Unreal Engine 5.5 Release Notes

What's New?

The release of Unreal Engine 5.5 continues to improve the UE5 toolset. This release delivers improvements in a wide variety of areas, including Animation, Rendering, Virtual Production, Motion Design, and more.

This release includes improvements submitted by our community of Unreal Engine developers on GitHub. Thank you to each of these contributors to Unreal Engine 5.5: a-canary, aharvi, Akymbo-Humanoid, AlbinBernhardssonARM, aliemci, alikomurcu, ALiwoto, Almax27, Ambrosiussen, arkadiusz-filip, batlam987, ben-mkiv, BenjaminHill, BenVlodgi, BlenderSleuth, bmwhitley, brorbw, bunnylacey, Caffiendish, chriszuko, colonelsalt, Corey-Downing, David-Vodhanel, dgiannetti-riot, dorgonman, DoubleDeez, DPons97, drandall-microsoft, Duroxxigar, duyaokun, dwdamien, dyanikoglu, dzeligman, Ebrahim-Mottaghi-Rezaei, Edstub207, efokschaner, erebel55, ersenal, ersh1, exxello, foobit, Frigerius, gamethread, GaoYuanBob, Garashka, gnu-enjoyer, GracesGames, grafikrobot, Gusten, hozuki, HSeo, hui211314dd, ilkeraktug, IvayloH, jashking, jdperos, Jernias, jerobarraco, jinsongh2, jorgenpt, jppiiroinen-h13, jpritchard1010, just-bank, KaosSpectrum, kdada, kdbn, KeithMorning, KeithRare, KirillAlekseeenko, klukule, kronok, laycnc, ligazetom, lightbringer, lijenicol, liuhao0620, LizardThief, Losdrew, lxcug, MagForceSeven, MarcusSvensson92, MaximeRobinot, Maxmystere, maxon887, Meidozuki, MinusKube, mr0ptimist, mrobitaille-riot, najmm01, nickdarnell, nicoell-threedy, nikitakrutoy, ohmaya, pasotee, PetterVMC, PFGschen, phantom10111, PhDittmann, PICO-XR, ppchavan001, pramanc, projectgheist, pzychotic, r-vaillant, ramiroagis, rdunnington, reapazor, RiotAlam, rmobbs-ml, sadunkit, sheepandriy, Sigma-Erebus, Skylonxe, sleeptightAnsiC, slonopotamus, Sluggernot, SRombauts, StalkMen, stanley1108, StefanZimecki-Sharkmob, sunwtGitHub, supuo, TechNXGEN, teddemunnik, tgraupmann, Th3Fanbus, TheLumbee, tigerjang, tntnkn, TroutZhang, Tt-Wes, TwentyPast4, uextm, Urkaz, user37337, Vaei, Vesros, vgpechenkin, vorixo, Voulz, Wellwick, whalefood, xeru98, zachlute, zeaf

Character and Animation

Sequencer Usability

Unreal Engine 5.5 brings usability improvements to Sequencer, enabling cinematic artists to control their view of contents within a sequence, gain easier access to properties, and filter viewport by sequence contents. This provides a more controllable interface to reduce workflow fatigue, helping users to create faster.

• Customizable Filtering

• Isolate or Hide Selected Bindings, Tracks, or Channels

• Hotkey Support for Hide, Isolate, and Show All

• Overlay Window for Properties of Bindings, Tracks, Sections, Channels, and Keys

• Toggle to Filter Viewport Selection of Sequence Contents

• Take Recorder now generates thumbnails based on your recorded cameras

Dynamic Sequencer

Dynamic Sequencer provides users the ability to better define dynamic operations of data to enhance interactive cinematic experiences.

Core Functionality:

• New Default Binding Type - Replaceable that can be dynamically bound at runtime to a different object

• Creating Custom Binding Types - More control over how an Object is bound in Sequencer

• Conditionally control a track row's or section's active state

• Time Warp a Sequence, Subsequence, or Skeletal Animations with an authorable Curve

• Override and animate the Transform Origin of a Subsequence or Shot

Animation Mode: Animation Layers

Animation Layers allow users to create motion on non-destructive layers for added control and flexibility. This takes advantage of the Section workflows in Sequencer while adding a simpler, cleaner interface for managing those Sections/Layers with lots of improvements to the usability.

Core Functionality:

• Create Layer from Selected

• Multi Object Layers

• Merge Selected Layers

• Additive and Override

• Mute, Lock, Select

• Animatable Weights

• Rename, Duplicate, Delete

Modular Control Rig (Beta)

Modular Control Rig moves into Beta, adding many quality of life improvements refining the user interface to help build rigs faster.

• Module Variants enable Modules to be easily updated.

• Schematic Overlay UX improvements.

• Module Hierarchy simplification

• New Modules:

  • Quadruped Modules

  • Vehicle Modules

• Native Bipedal module support for common skeleton types (Vicon, Mixamo, mGear, HumanIK, Motive, XSens, Advanced Skeleton).

Rig Variants (Experimental)

Rig Variants are highly experimental tools for upgrading and swapping Control Rig Modules and Functions, enabling animators to swap rigs non-destructively to a different variant for backwards and forwards compatibility.

• Upgrade and swap Control Rig Modules and Functions with a new variant.

Mutable Customizable Characters and Meshes (Beta)

Mutable generates dynamic skeletal meshes, materials and textures at runtime for creating character customization systems and dynamic content.

• Hidden surface removal to prevent z-fighting and implement object layering and interaction. Ex: jackets over shirts over the base body.

• Mesh and texture merging to reduce draw calls.

• Morph baking to reduce GPU load.

• Baked texture effects such as layering and decal projection to reduce GPU load.

• Graph-based editor.

Skeletal Editor (Production Ready)

The Skeletal Editor is now Production Ready with general improvements and visual feedback updates for working with Character Meshes within the Skeletal Editor, enabling quicker and simpler workflows for painting and editing weights on skeletal meshes.

• Isolation of meshes

• Robust weight transfer tools

• Edge & Face Selection with Grow/Shrink/Flood support

• LOD & alternate Skin Weight profile editing

• Improved viewport wireframe and bones display

• Improved Component Editor

• Lasso selection

• Experimental Quad Mesh editing

• Bones marquee selection & multi-editing

Animation Deformers

You can now craft more realistic animation effects such as contact deformation or better cartoon-style squash-and-stretch, with the new ability to spawn custom deformers inside Control Rig, and easily apply them to characters in Sequencer with a single click.

There’s also an Animator Kit plugin containing a collection of ready-made Control Rigs with built-in deformers—including Lattice, Camera Space Lattice, and Sculpt—that you can use during animation or as examples for building your own rig-driven deformers.

ML Deformer

ML Deformer brings high quality offline mesh deformations into real-time by leveraging Machine Learning. Examples of this are muscle and quasi static cloth simulations. For UE 5.5 the ML Deformer adds some additional features that can improve the runtime deformations.

Changes from 5.4 to 5.5

• Added support for painting masks, directly in the viewport of the ML Deformer editor.

• Ability to provide a mask per training animation/geom cache input, limiting the training data to a specific area.

• Added a pose mixer tool to the Maya plugin for ML Deformer, which can be used to improve training data.

• Improved workflow issues resolved based on feedback from internal and external teams.

Physics Control

The Physics Control plugin allows you to add simple, intuitive, and powerful physically based controls to either a blueprint using a component, or to a character using an animation graph node. This helps you gain the benefits of emergent physical motion of static and skeletal meshes, whilst still retaining artistic and gameplay control.

• Refined Control Profile API that can be applied to either the Physics Control Component or to the Rigid Body With Control animation graph node

• Improved Control Profile Asset Editor

• Simplified Creation of Control Profiles

Choosers

Choosers have arrived and are production ready in 5.5. Choosers provide a robust game context asset selector with a lot of excellent additional features and debugging. While the driver was animation originally, we exposed Choosers to be able to select nearly any type of asset for the release. This can encompass multiple levels of complexity, from simple random selectors to database-driven logic involving 1000s of animations.

Audio Driven Animation for MetaHuman Animator

Generate high quality facial animation from audio to quickly deliver convincing facial performance in MetaHuman Animator.

• Use audio assets in MetaHuman Animator to generate facial animation.

• Quickly delivers animation for all MetaHuman facial controls, including inference of upper face gestures.

• Works with various voices and languages.

• A fully local, offline solution, suitable for batch-processing audio.

To learn more about audio driven animation, read the Audio Driven Animation for MetaHuman documentation.

Optimized MetaHumans in UE

With release 5.5 we've taken the optimization approaches used to great success to bring MetaHumans to UEFN and applied the same techniques to UE MetaHumans. Now when exporting MetaHumans, users will be able to request either:

• Cinematic (Complete) - Existing 'full-fat' MetaHumans with original resolution assets or,

• High, Medium and Low (Optimized) - Optimized MetaHumans with baked textures and reduced complexity.

This enables the average size of a cinematic MetaHuman to be reduced from 800MB to just 60MB, with only minor loss of fidelity when the High (Optimized) option is selected.

This feature also introduces the MetaHuman Component, which consolidates the important configuration options for your MetaHuman. This provides a unified interface for users to further configure their MetaHumans by allowing them to turn on/off character animation features at certain LODs, enabling a trade off between performance & fidelity.

To learn more about optimized MetaHuman, read the Optimized MetaHuman in Unreal Engine documentation.

Rendering

MegaLights (Experimental)

MegaLights is a new Experimental feature that allows artists to add hundreds of dynamic shadow-casting lights to their scenes. Artists can now light scenes playfully without constraints or impact on performance. With MegaLights, lighting artists, for the first time, can use textured area lights with soft shadows, lighting functions, media texture playback, and volumetric shadows on consoles and PC.

For more information, see MegaLights

Lumen Improvements

Release 5.5 includes multiple improvements to Lumen HWRT performance, focusing on being able to ship Lumen at 60hz on consoles. There are also several notable improvements which increase the quality of Lumen global illumination (GI) and reflections. Lumen now supports hit-lighting for GI, a more expensive and accurate way to calculate GI, which avoids some of the limitations when using Lumen with static meshes. Another important improvement is the new reflection denoiser that substantially improves the sharpness of low roughness reflections as well as new support for translucency with refraction in reflections.

Hardware Raytracing

Release 5.5 has made many improvements to the underpinning systems which all fall into the external-facing hardware raytracing category (HWRT). These lower level systems all impact the performance and capabilities of Lumen, Path tracing, and Light Baking. There are improvements to asynchronous evaluation of raytracing code, improvements to caching and better management of acceleration structures. The intent of these changes is to make it feasible to utilize HWRT at higher refresh rates on platforms for which there is hardware support.

For more information, see Hardware Ray Tracing.

Path Tracer

In Release 5.5 the Path tracer is Production Ready. This means the Path Tracer is fully featured and now it can also act as reference for Atmosphere and Volumetric clouds. It also has a new Spatio-Temporal denoiser for offline Rendering through Movie Render Queue and Movie Render Graph as well Linux support.

It is expected that some in development or experimental features will not work with the Path Tracer despite its Production Ready status.

For more information, see Path Tracer.

Path Tracer Volumetrics

In Release 5.5, the Path Tracer now supports reference quality rendering of both the sky atmosphere and volumetric clouds offering opportunities for a fully-featured reference or ground truth image creation.

In order to preserve interactivity, some optimizations to the ray marching technique can result in visual artifacts, and very dense cloud layers will often need careful tuning.

NFOR - Spatio-Temporal Denoiser (Experimental)

NFOR Denoiser, "Nonlinearly Weighted First Order Regression" or "Spatio-Temporal Denoiser" is a plugin designed to provide temporally stable denoising to offline Path Tracing renderings by denoising each pixel based on the surrounding patches in both time and space.

This feature is not targeted towards extreme low sample count and or fast moving objects, but to produce a high quality output.

For more information, see NFOR Spatio-Temporal Denoiser.

Vulkan Ray Tracing (Beta)

In Release 5.5 Vulkan Ray Tracing is now enabled by default.

Vulkan Ray Tracing features are now at parity with DX12, including on the Linux platform. This will allow the full suite of ray tracing features to be used, including Hit Lighting mode in Lumen and Path Tracing.

Recent drivers are recommended for anyone trying this feature (on Nvidia 560+for Windows and 550+for Linux).

Render Pass Improvements

In Release 5.5 it is now possible to author scene captures and custom render passes which automatically mirror the main view’s camera and resolution, including temporal AA jitter and screen percentage. This allows compositing layers to be pixel identical, and compositing in general to take advantage of screen percentage for better performance.

Additionally, a user defined intermediate texture, dubbed "UserSceneTexture" can be written to and read from sequentially as a post process material. This means that UE now supports running multi-pass post process effects (such as separable filters or blurs) in a more performant manner.

Mesh Texture Color Painting

In Release 5.5, we now support mesh painting on Nanite mesh instances with minimal performance and memory overhead. Before 5.5, the use of Nanite prevented these common mesh painting workflows which allow local variation of appearance for instances of the same geometry.

For 5.5, the Mesh Paint Tool has been extended to add a new Texture Color painting mode that paints to virtual textures stored on mesh components. This is to support workflows similar to vertex painting, but that scale with texture resolution instead of vertex count which works more efficiently with Nanite meshes. Support for copying between vertex and texture color painting has been added, and there is an option to auto propagate texture colors to vertex colors while painting.

For more information, see Mesh Painting.

Orthographic Rendering

Orthographic Rendering is commonly used in Architecture, Engineering and sometimes as a stylistic choice for Gameplay. Similar to an isometric view, all objects appear at the same scale, parallel lines remain parallel and scale is represented consistently in the drawings / images, making it easier to judge relative sizes.

In Release 5.5, Orthographic Rendering is at visual parity with Perspective Rendering, supporting most rendering features In Raster and in Path Tracer.

For more information, see Orthographic Camera.

Render Parallelization

For 5.5 there are improvements to parallel translation, which issues RHI (Render Hardware Interface) tasks to translate RHI command lists into platform command lists. The impact of this change is a dramatic performance increase of up to 2x (dropping by 7ms on some platforms), reducing the number of stalls, and offering a minor reduction in drawcalls as well as small improvements to platform dynamic res and render thread time.

Release 5.5 also includes improvements to asynchronous RDG (Render Dependency Graph) execute tasks which benefits both critical path rendering thread time on the order of 0.4ms, as well as allowing asynchronous execution of approximately half of slate rendering.

Day Sequence (Experimental)

Day Sequence is an Experimental plugin that automatically generates a 24hr Day cycle allowing artists to easily create their lighting with artistic control over Sun, Moon, Stars, Atmosphere and Clouds from within the Sequencer tool.

In addition to doing much of the work a user would need to do to get a basic day/night cycle into a game, Day Sequence also handles network synchronization (out of the box multiplayer support), POI creation using volume overrides, procedural sequence creation to emphasize data oriented approaches to lighting.

Bindless Rendering

Bindless resources are a low-level feature related to the management of textures and other types of data buffers in modern Renderer Hardware Interfaces (RHIs) such as DX12, Vulkan, and Metal. Adding support for bindless resources will allow for more flexible GPU programming paradigms and additional features within the renderer, and is also a requirement for full ray tracing support on Vulkan.

With Unreal Engine 5.5 the number of platforms which can use Bindless Resources has been increased.

First Person Rendering (Experimental)

In 5.5, we've added initial support for first person rendering, which includes preventing player hands/weapons from clipping into in-world objects, a separate FOV which allows developers to specify a FOV that differs from the rest of the world for their first person assets.

The first person rendering feature works with all the major primitive types and materials, including opaque, translucent and also Niagara particle systems, as well as with Nanite geometry. New blueprint functions have also been added for transforming between world and first person spaces.

Local Fog Volume

Local Fog Volumes are actors that can be placed to quickly create local variations of fog in a simplistic and efficient manner. Local Fog Volumes, unlike volumetric fog, work across all platforms and scalability levels making them ideal to use for low-end and high-end platforms by providing consistent visuals with other fog and lighting systems.

Local Fog Volumes are Production Ready with Unreal Engine 5.5.

For more information, see Local Fog Volumes.

Light Function Atlas

The new Light Function Atlas accelerates rendering of various passes using Light Functions by baking down the Light Functions to a texture which is then projected onto the scene instead of recalculating the Light Function material inline for each light. This can result in significant savings of GPU time. While this method has some limitations, it permits the use of colored light functions as well as the use of light functions with Megalights.

For more information, see Light Functions.

Substrate (Beta)

Substrate materials have moved to Beta status as of Release 5.5. They have not yet been proven in large scale production, but all the features of legacy materials are supported, and more importantly, all the platforms which UE deploys to are supported. Work on cook times and memory footprint for materials is ongoing, and should be further improved when Substrate reaches a full production ready status.

Heterogeneous Volumes (Beta)

Heterogeneous Volumes (HVs) in Niagara allows importing VDB volumes into Sparse Volume Textures for rendering. Unreal Engine 5.5 brings numerous improvements to HVs:

• Scalability control for Gen9 consoles performance

• Ability to render multiple overlapping HVs

• HVs apply self-shadowing when incorporating indirect lighting

• Holdout support in Movie Render Graph, including path tracing

Volumetric Cloud Material Update

The new Volumetric Cloud material is an evolution of the previously provided material provided with the Engine Content. In 5.5, this material has been modified to be simpler, clearer, and easier to configure to achieve a desired appearance for clouds of different types and shapes.

Because this material completely replaces the original, all templates and projects which use the original Volumetric Cloud material are automatically updated in 5.5. It is expected that some projects may look different or have trouble finding the right resource because of this. If your project depends on the previous material, the simplest solution is to migrate it from 5.4 or earlier to 5.5.

For more information, see Volumetric Cloud Material.

Virtual Production

Virtual Scouting

The new Virtual Scouting tools introduced in UE 5.4 have been improved with the addition of a VR content browser, BP customizable gizmos and further polish increasing the customizability of the whole toolset.

With UE 5.5, Virtual Scouting is considered Production Ready.

Users can now access a powerful out-of-the-box experience using OpenXR compatible HMDs (Oculus and Valve Index supported by default) and dev teams now have an extensive API for building custom tools and UX.

The legacy Virtual Scouting tools remain functional in UE 5.5 but will be removed in UE 5.6.

Live Link Hub (Beta)

For UE5.5 Live Link Hub will move up to Beta status. This release we focused on features for professional users, while maintaining the ease of use from the initial UEFN focused release:

• 3rd Party Plugins - Live Link Hub can now load Unreal Editor Live Link plugins, enabling the whole 3rd Party ecosystem of Live Link data sources.

• Data Retiming - Hub now supports selecting a single subject as the source of timecode and synchronization for all other subjects, allowing users to set all subjects to a common framerate. This provides consistency when recording Live Link data in Take Recorder and adds timing data to subjects which do not have it by default - eg LiveLinkControllerInput and XR sources.

• Timecode support - Live Link Hub can make itself the Timecode provider for all it's attached clients. Simplify the process of getting all your engine sessions synced without the need for SDI hardware.

• Virtual Subjects - Virtual subjects are now supported in Live Link Hub. You can merge multiple animation and basic role subjects into a single subject for simpler in-engine consumption.

• Skeletal Attachments - Virtual subjects now support skeletal attachment. Merge mocap glove data with body data into a single Live Link subject.

• Recording - record raw data for later playback. Recordings are written asynchronously and can be accessed as soon as recording has finished.

LiveLinkOpenVR

Responding to LiveLinkXR plugin user feedback , we have created a LiveLinkOpenVR to address VP workflows. LiveLinkOpenVR has the same UI & UX but is specifically created for SteamVR tracker > Live Link workflows. LiveLinkOpenVR is available in Live Link Hub and within Live Link in UE. No command line arguments are required and VR rendering is still accessible.

Timecode Improvements for Performance Capture

• Sequencer TC - You can now view your Sequencer timecode in the viewport via the Stat SequenceTimecode command. Sequence timecode as well as Take Recorder Timecode can be viewed.

• Animation Asset Editor Timecode - the animation asset editor for Animation Sequences now displays timecode if this has been imported as a custom attributed or plotted to the root bone via Take Recorder.

• LiveLink Take Recordings - LiveLink Subject Take Recordings now receive timecode tracks, the same as regular actor recordings, enabling you to QA timing and synchronization.

• ProRes media TC support - Media Assets using ProRes files with Timecode embedded now have timecode metadata. This enables automated syncing in sequencer, providing parity with Anim Sequences & Soundwave assets. Sequencer Media track sections now receive correct TC if it is present in the imported movie file.

• Image Based Media TC support - Img Media Files have user editable TC metadata, again to support automated synchronisation in Sequencer timelines.

• Subframe support in Take Recorder - subframe is now as a plotted float value on Take Recordings.

Camera Calibration Accuracy

The Camera Calibration solver now leverages calibrator tracking information to drastically improve accuracy in lens and camera parameters estimation, and does not rely on precise mounting of the tracking device. The system can also solve for both Lens Distortion and Nodal Offset simultaneously to speed up the overall process for the operator.

In addition, adaptive resolution when using overscan is now available, as is the ability to apply lens distortion with TSR, both of which can improve visual quality.

Per-Light Card Over/Under Inner Frustum Controls

Currently the option exists for Light Cards to be over or under the Inner Frustum but this setting is global to all Light Cards in the scene. The ability to have per-Light Card control is a common request, as there are frequently situations where Light Cards must be near the Inner Frustum but selectively over or under based on the shot.

Level Visibility Controls

Toggling sublevels is a common workflow for stage operators and doing this with multi-user requires the "Hidden in Game" checkbox rather than the (Editor) Visibility checkbox. The Levels window only shows the (Editor) Visibility option so the current workflow requires opting in to a CVAR that attempts to synchronize the two checkboxes and transact them to multi-user. This is fragile and error-prone, and there is no way for the stage operator to easily fix the problem if they get out of sync. Both checkboxes should be displayed in the Levels window for transparency and simplicity.

Color Grading Panel

The enhanced color grading UX in the ICVFX Editor is relevant and applicable to any Unreal Engine artist who works with color grading in Post Process Volumes and Color Correction Regions, even if nDisplay is not involved in the project. As such, this panel will be promoted up for general editor use and made available to all artists.

Production Ready SMPTE 2110 for ICVFX

As productions begin to transition over to SMPTE 2110-based deployments, Unreal Engine will continue to prioritize improvements to IP video signal flow that ensure it is ready to meet the needs of real world In-Camera VFX projects. While initial support for the end-to-end workflow was introduced in Unreal Engine 5.3, in UE 5.5 we provide Production-Ready SMPTE 2110 support via the following:

• Numerous stability improvements to Unreal Engine's core SMPTE 2110 support.

• Automatic detection and repair for instances where the system loses framelock to ensure synchronization is preserved continuously.

• Ability to use PTP as a Timecode Provider.

• Ability to timecode-align 2110 external media inputs.

• OpenColorIO support for 2110 media sources.

Overscan For CineCameras and MRQ

The CineCameraActor now supports an overscan multiplier. Render additional pixels at the edges of your frame to improve Screen Space Post Processing accuracy, add camera shakes in post, or accurately distort the image through Lens Distortion.

Overscan is supported on the CineCameraActor and in Movie Render Queue.

Virtual Camera - Post Smoothing

Non-destructively smooth out your Virtual Camera moves after the fact directly from the device. The original move is always preserved so no data is ever lost!

Virtual Camera - Photography and Bookmark Browser

Virtual Camera can now take photographs, which are dropped directly into your project's save folder for easy review and sharing.

Snapping a photograph also creates a bookmark, which can be viewed from the new Bookmark Browser and quickly jumped back. The Bookmark browser allows users to search, sort, favorite, and rename their bookmarks through a visual interface.

Virtual Camera - Take Carousel

Easily review and cycle through your recordings with the new Take Carousel! Swipe through the carousel to see previews of your recordings and quickly load them for review.

Access the carousel through the previous recording preview thumbnail on the Virtual Camera's main screen.

Multi-User Replication (Beta)

Multi User Replication has undergone a series of UX and technical improvements and is now officially in Beta. Multi-User Replication allows users to specify properties and actors to replicate to other clients in an MU session in real-time and without the need to wrap your changes in transaction and flood the undo buffer if they need high frequency replication. Save and Load Presets to make curating your replication setups significantly faster.

Developer Iteration

Zen Server - Snapshots for Faster Build Farm Cooks (Experimental)

Cooking relies on a persistent state on the build agent in order to not re-cook the same data again. There is no guarantee that the exact same agent will be assigned the next cook job.

The Zen Server Snapshot stores the state of the cook job so it can be restored quickly and re-used for a new job on another build agent resulting in a faster, incremental build farm cook.

Zen Server - Streaming to Target Platform (Experimental)

Zen Server is the new architecture for new local/shared data Unreal Engine Derived Data Cache (DDC). It provides improved data conditioning and read/write performance by no longer storing outputs as loose files on disk.

Instead of time consuming full copy deployments, the server component enables local network streaming of cooked data directly to a target platform for the game client and game server for faster 'play on target' iteration.

Unreal Zen as Shared DDC

In Unreal Engine 5.5, deploying Zen server as a shared DDC is now production ready for Windows host machines.

Replaces use of network file shares as DDC storage with new Unreal Zen storage server architecture. Zen is more latency tolerant and optimized for network communication, reads & writes to/from remote machines; operations no longer do synchronous IO at the DDC storage level.

UBA C++ and Shader Compilation

In the Unreal Engine 5.5 release UBA is production ready for Windows host build machines. Unreal Build Accelerator (UBA) is a local and distributed compilation solution for C++ and Shader Compilation used in conjunction with Unreal Build Tool and/or Horde’s Remote Build (compute task) system. Unreal Horde functions as the job pool coordinator to assign UBA agent helper resources on your build farm resources. UBA transmits local data, executes the remote task and returns the results.

Please note for macOS and Linux host build machines, C++ compilation is stable and ready to use for production however shader compilation on those platforms remains in beta.

Zen as Cooked Output Store (Beta)

Previously cooked output data was stored as loose files on disk introducing filesystem process overhead. When enabled in the project settings, platform cooked data will now be stored in local and/or remote in Unreal Zen Storage server which provides better data conditioning local + network I/O performance.

Unreal Horde CI and Remote Execution

Unreal Horde Continuous Integration & Remote execution is officially production ready for Unreal Engine 5.5

Horde is an 'out of the box' continuous integration solution designed for any Unreal Engine development team. Horde is a horizontally scalable, distributed continuous integration and build platform system hooked into Perforce, and tightly integrated with Unreal Engine developer iteration tools and workflows.

Zen Loader in Editor By Default

New Zen loading architecture is considered production ready in Unreal Engine 5.5 and is enabled by default. Zen Loader reduces overhead and optimizes the asset loading path to increase performance from starting the editor, loading a map, and loading into Play In Editor (PIE), as well as the various cook processes.

Motion Design

Cloners and Effectors UX Enhancements

The latest release of Cloners and Effectors enhances creative workflows with powerful new features. Effectors now include Push Apart for seamless object distribution, Particle Color for dynamic visual control, and Invert Volume for flexible manipulation. New shapes like Torus and Radial expand design possibilities. Cloners bring advanced particle emitter workflows to spawn and manage particles, along with point-based dynamics for realistic interactions. The ability to create instances and static meshes adds versatility, making this update a must-have for artists seeking efficiency and precision.

Cloners and Effectors Proximity Effects

The Effectors System provides a powerful solution for colorizing cloner particles, offering seamless integration with both cloners and materials systems. By transmitting data between the Effector and Cloner systems, users can intuitively apply and control particle colors across large sets of clones. This system ensures dynamic and responsive color effects, perfect for achieving complex visual results without manual adjustments.

Cloner and Effector Parameters

• Effector Count

• Random

• Mesh Index

• Normalized Age

• Index

• Count

• Color

• Effector Weight

• Progress

• Mesh Count

• Position

• Velocity

• Velocity Normalized

Cloners and Effectors Collision

Cloners and Effectors now feature robust particle and mesh collision capabilities, enabling intricate procedural effects and dynamic interactions. Clones can effectively collide with one another, preventing unwanted intersections, while also interacting with other meshes within the environment. This added collision functionality provides for more realistic and controlled outcomes, opening up possibilities for complex simulations and refined visual effects.

Push Apart Effector

The Push Apart Effector is a powerful tool designed to push cloners away from the effector's center point. Ideal for generating force field-like effects, this effector enables controlled separation and dynamic spatial interactions, enhancing flexibility and precision in your projects.

Material Designer PBR Workflows

The Material Designer now supports complete PBR workflows, providing artists a method to build complex materials with ease. Each channel features a stacking system, helping users to layer multiple images, colors, and noise patterns to achieve intricate material designs. This workflow also includes multi-texture drag-and-drop functionality, facilitating quick and efficient material creation.

Material Designer Texture Sets

The Material Designer now supports full drag-and-drop functionality for texture sets, streamlining material creation. With name matching for each slot and channel packing for identifying specific channels, such as ORM maps, artists can quickly and efficiently build materials. This feature accelerates the workflow, making material development faster and more intuitive.

Material Designer Effects

The Material Designer now includes a range of material effects, such as color correction, distortion, generators, and blurs, providing faster and more intuitive creation of complex materials. Artists can apply these effects and procedurally toggle them on or off. Additionally, all effects can be animated in Sequencer, allowing for the development of intricate, dynamic visuals.

Text Animators

Animators can now create text animations in Unreal Engine with unprecedented ease thanks to procedural, non-destructive features. These tools can precisely target individual characters, facilitating dynamic and playful text effects. The non-destructive approach ensures effortless adjustments, providing artists with enhanced control and flexibility throughout the creative process.

Property Animators

Animators is a powerful feature that drives most properties in Unreal Engine through procedural animation, providing users a way to easily control position, scale, rotation, visibility, and more with just a few clicks. The latest release introduces a new curve animator for smooth in, out, and looping animations, perfect for pop-up style effects. Enhanced Sequencer support now allows Animators to be added as a track, enabling easy drag-and-drop timing while preserving all procedural animations. Additional features include fade in/out tracks, as well as copy, paste, and full preset support for efficient workflows.

Transition Logic

In live television, the seamless presentation of multiple on-screen elements and their smooth transitions are paramount. Transition logic plays a pivotal role in precisely controlling the entry and exit of elements during live shows based on assigning various on-screen elements to "layers." This capability empowers designers to intelligently structure graphic systems, ensuring that each element appears and disappears on the screen exactly as intended, providing a level of precision essential for impactful live broadcasts.

Transition Logic Features:

• Transition Tree for deciding transitions

• Add multiple elements to a layer

• Tag up elements in a single level to dynamically transition without the need to split a single graphic up into multiple.

• Simplified, up-front setup, with optional complexity under the hood, using the Transition State Tree

Simulation and VFX

Chaos Dataflow Editor (Experimental)

The Experimental 5.5 Dataflow Editor graph allows for the procedural generation of asset within a Node based environment. The implementation of the graph utilizes a pull-based evaluation, where the nodes of the graph generate a cached output state based on the evaluation of its inputs. Dataflow assets are used to assist in the procedural authoring and setup of simulation systems. For example, the Chaos Cloth system uses Dataflow to import and set up garments from Marvelous Designer.

5.5 Updates include:

• Reroute nodes

• Copy and Paste

• Better Undo Support

• Deprecation Support

• Dynamic Inputs

• Show/Hide Pins

• Ability to colorize comments

• Grayed out disable nodes

• Node versioning (for developers)

• Any type support

To learn more about the Chaos Dataflow Editor, read the Dataflow Graph documentation.

Chaos Flesh (Experimental)

For 5.5, the Experimental Chaos Flesh release focus includes finishing a simple single animated muscle, a simple ML example, and a full muscle simulation. We are currently working on fat layer simulation, with remaining tasks including setting static constraints between muscle and fat in the same graph, validating the appearance of the driven SkeletalMesh, and training an ML model for SkeletalMesh from GeomCache.

Chaos Visual Debugger (Beta)

Released as Beta in UE 5.4, the Chaos Visual Debugger is a tool that allows you to record the state of the physics simulation (in-editor or packaged builds), to later visualize it with the ability of scrubbing back and forth in time, and inspect the recorded data in a per-object level.

In UE 5.5, the Chaos Visual Debugger is still in Beta, but we have added new features and made several improvements to it.

New Features

• Scene Query Browser: Now you can see all scene queries made in any given frame, search by tag name, type, etc. In a new dedicated, Scene Outliner like window.

• Recorded Output log : CVD is now able to show the recorded output log, similar to how Unreal Insights does it. When you scrub to any frame within CVD, the correct log line will be selected and visualized. In addition, when you select any log line, the corresponding frame will be visualized.

• Network Tick Sync mode: In PIE Sessions, CVD was already able to record server and client data, but they were synchronized using timestamps. In 5.5, we are introducing a new "Network Tick" sync mode, that will calculate and apply the required offsets to show the visualization as the expected state taking into account client side prediction. In this mode, any divergence you see between server and client, indicates a network de-sync.

• Collision Geometry Inspector: A new details panel that allows you to see recorded data per collision geometry (not just from a whole particle / rigid body). This panel under the hood processes all the chaos data and decodes it back into the settings used in the Unreal Editor. For example, it shows if a shape is query only, query and physics, etc. Collision Channel and Collision Channel response matrix

• Recent Files: Now the last 5 files opened in CVD are remembered and can be assessed via the file menu.

• Acceleration Structures: CVD now records and visualizes the acceleration structure used by our scene query system.

• Character Ground Constraints: We added support to record & visualize character ground constraint data. This is the constraint type used by our Physics Based Character Movement system

• Generic Debug Draw : Now you can record simple shapes (Sphere, Boxes, Lines) using Macros in C++ or dedicated BP nodes in Blueprints, that then will be visualized with the rest of the simulation in CVD.

Improvements

• Performance: On the fly geometry generation was improved by removing work that could be skipped, and moving more of the remaining work into worked threads. We will continue improving this area in future releases

• Show Menu: In 5.5, we have re-made the Show menu to be a proper UE tool menu, and added Save support. Now all available visualization flags are organized in submenus and sections. In addition, when you change a visualization flag, the new setting is auto-saved (you can revert to default if needed).

• Particle Colorization: In UE 5.4 we were using the color scheme used by Chaos Debug Draw. That color set is good for wireframe representations, but it is not ideal for solid representation. UE 5.5 now uses a less intense color scheme, which can be changed if desired.

• Scene queries : The scene query inspector now decodes the collision query response flags to show the collision channel response matrix.

Chaos Destruction

In 5.5, Chaos destruction features comes with the following improvements

Unreal Editor improvements

• Geometry collection are now properly displaying their collision when using the following collision modes are selected :

  • Player collision

  • Visibility collision

Memory improvements

• In 5.5, memory footprint of Geometry Collection component and their corresponding physics proxy has been reduced allowing for better scaling

Root proxy only Custom renderer

• A new custom renderer has been added to allow rendering root proxy meshes using Instanced Static Meshes but uses the normal renderer for rendering the broken state The new renderer is : GeometryCollectionRootProxyRenderer

Dataflow

• A Simulation view has been added to the Dataflow Editor for Geometry Collections allowing to see the final geometry collection produced by the graph along with the debug view that displays the selected node results

• Several new nodes have been introduced or improved to closely match the tools available in the Editor Fracture Mode

• Improved existing fracture nodes to better match the parameters in the fracture editor tools

• New Radial point distribution node

• New Mesh cutter node

• New FixTinyGeo node

• New Recompute normal node

• New Validate node

Caching

• Cache collection now have a new interpolation modes to address limitation of the default one Default interpolation mode is sometimes not enough when using large time steps or when replaying in slow motion

We added an option to allow users to choose a different interpolation method.

• Quat Interp:

  • Using the regular FTransform Blend method with standard quaternion interpolation

  • Have limitation when time step is large or very small ( slow mo )

• Euler Interp: rotation are interpolated in euler angle space

  • May not interpolate along the shortest path

• Dual Quat Interp: use double quaternion method to interpolate rotation

  • Most precise method in extreme situations

  • But potentially slightly slower to evaluate

Chaos Modular Vehicles (Experimental)

The 5.5 Experimental Modular Vehicle System is a vehicle simulation plugin that enables real-time vehicle construction and destruction, allowing components to be added or removed dynamically.

Changes from 5.4 to 5.5

Unlike the existing Chaos Vehicle Plugin, which uses a fixed skeletal mesh topology, the Modular system is more flexible, supporting custom simulation modules and client-predicted, server-authoritative physics with rewind resimulation. Vehicles are built from multiple GeometryCollection Actors, combined within a Cluster Union Actor, with plans to support Static Meshes. The simulation is modular, with components assigned to a simulation tree, enabling the creation of both traditional and unconventional vehicles.

To learn more about modular vehicles, read the Chaos Modular Vehicles documentation.

Niagara Lightweight Emitters (Beta)

The new Lightweight Emitters do not store any state from frame to frame, only visible proxies will have data calculated for them. This allows for significantly higher emitter counts and includes a constrained, faster feature set to increase productivity and drastically decrease runtime cost and compile times for simple behaviors.

Lightweight Emitters were introduced as an Experimental feature in Unreal Engine 5.4. They now ship as Beta in Unreal Engine 5.5.

To learn more about lightweight emitters, read the Niagara Lightweight Emitters documentation.

Niagara Data Channels

Niagara Data Channels (NDCs) allow passing data between Niagara Systems and between Niagara and other parts of the engine. One important use case has been to use NDCs to inject events into large shared Niagara systems to enable better performance for things such as impact FX.

NDCs are now Production Ready with Unreal Engine 5.5, with improved user experience and runtime capabilities.

To learn more about data channels, read the Niagara Data Channels documentation.

Worldbuilding

External Data Layers

Actors within a World Partition level can now be associated to a specific Game Feature Plugin using External Data Layers. Data Layers can also be parented to External Data Layers. The resulting streaming levels generated from this association will be injected only upon plugin activation which can be set at runtime.

Leveraging the Data Layers editor, actors can be assigned, moved or removed to External Data Layers. Additional plugin dependency validation occurs to prevent invalid combinations.

Ultimately, using External Data Layers allows for various Game Feature plugins to add actors into levels without affecting the base game content making them ideal for DLCs and live game operation.

Static Lighting (Experimental)

Experimental support for Static Lighting added for World Partition levels and Level Instances. Both lightmaps and volumetric lightmaps techniques are supported using CPU Lightmass.

Lightmaps data in world partition level is packaged per grid cell for streaming according to their Actor streaming settings. Volumetric Lightmaps use independent Cellsize and distances which can be adjusted under World Settings - Lightmass.

A new World Partition Static Lighting commandlet builder is provided and is recommended for loading and baking static lighting in World Partition levels.

It is required to allow Static Lighting in project settings and include r.AllowStaticLightingInWorldPartitionMaps=1 to the DefaultEngine.ini config file.

Commandlet example:

-run=WorldPartitionBuilderCommandlet -AllowCommandletRendering -Builder=WorldPartitionStaticLightingBuilder -Build -LogCmds="WorldPartitionStaticLightingBuilder "

Procedural Content Generation (PCG)

GPU Compute (Experimental)

Added support for GPU Compute in PCG Framework.

Using PCG GPU compute allows to harness some of the power of GPU hardware for parallel & computation-intensive processes. Behind the scenes, PCG compiles a graph of kernels for the execution on GPU.

The data can be transformed to and from CPU seamlessly.

It can also write directly to the GPU Scene, allowing fast and efficient spawning of large amounts of static mesh instances with no impact on CPU performances. Writing directly to the GPU Scene comes with limitations including no collision and indirect lighting support.

This first experimental version includes:

• Custom HLSL GPU Kernels nodes: Point Processor, Point Generator and Custom HLSL, which allows users to define their own input/output data and thread counts

• Access to points, attributes, textures and landscape data

• Basic functions are provided to read, write or output and custom user functions can be added per kernel.

• An HLSL editor with error reporting and syntax highlighting

• Copy Points operator updated with optional GPU Compute

• Spawn static meshes directly on GPU through a Procedural Instanced Staticmesh component.

• Chained GPU Kernels are compiled and executed as a single operation.

Remaining work includes converting more PCG nodes from the current library to run optionally on GPU, branching and CPU VM for headless server support.

Grammar

In the context of procedural content generation, "grammars" refer to formalized systems of rules that will define how the content ought to be generated or structured. Often, using a simple representation, such as a symbol or a word, these rules dictate how to combine or string together smaller elements, such as walls, columns, or panels, to create more complex structures, like fences or buildings.

In order to facilitate the use of grammars through the PCG framework, several new nodes have been introduced in 5.5. These new nodes are used to define shapes and subdivide them according to the grammar provided.

Nodes

• Select Grammar

• Print Grammar

• Clean Spline

• Reverse Spline

• Primitive Cross-Section

• Spline to Segment

• Duplicate Cross-Sections

• Subdivide Segment

• Subdivide Spline

Grammar syntax

Tokens:

Literal: Any string without spaces

Sequence: [a, b, c] Stochastic choice: {a, b, c} Priority choice: <a, b, c>

Repetitions (default: 1) Fixed number: [a, b, c]3

Zero or more: a*

One or more: {a, b, c}+

Weight in stochastic choices (default: 1) Weight specifier: {a**:3**, [b, c]*:2, {d, e}+:1}

Examples

[A, B*, C] [Entrance, {Corridor, Doors}*, Exit]

[Entrance, {Corridor+:2, Doors*}, Exit]

{[Entrance, Corridor, Exit], [Entrance, [Corridor, Doors]*, Exit]}

Graph Executor v2

The new version of the PCG Graph Executor scales better under multithreading applications, and makes it possible to run PCG tasks not bound to the engine frame time.

This helps limit the impact of PCG on responsiveness and framerate and improves execution wall-times significantly in both Editor and Runtime use cases.

Allowed execution frame time can be configured and balanced for both Editor and Runtime independently using these cvars:

pcg.EditorFrameTime

pcg.FrameTime

Geometry Processing

Model, modify, combine and output meshes directly from within PCG through UE's dynamic mesh type. This also allows mixing modeling and instancing, for different use cases within a single context.

Example: A PCG building generator can populate its sides with modules instances using a grammar and produce a unique geometry for its rooftop and floors. It can resample that produced rooftop geometry to spawn assets on top. It could also produce its own shape model to apply the grammar on using the Primitive Cross-Section operation.

Additionally, to provide efficient memory and performance when operating on meshes, PCG now allows for resource stealing between each operation thus avoiding expensive copy of data when possible.

This first implementation includes:

• Dynamic Mesh Data type

• Resource Stealing

• Static Mesh to Dynamic Mesh

• Create Empty Dynamic Mesh

• Get Dynamic Mesh

• Transform

• Merge

• Append Meshes from Points

• Spawn Dynamic Mesh

• Debug node support

• Export to Static Mesh with Save Dynamic Mesh to Asset

• Support for dynamic mesh input in the existing Mesh Sampler operator

• Full compatibility to extend functionality with PCG Blueprint Elements using geometry script functions

Spline Meshes

Create Spline Mesh node was added to easily assign meshes to their splines in PCG, making the process of creating spline mesh actors significantly easier.

Data Layers Support

Added support for transparent data layer assignment, such that content produced from a PCG component in a specific data layer configuration (including External Data Layers) will properly assign the same properties to its created artifacts.

World Raycast

World Ray Cast node was added as part of the effort to generalize ray casting in PCG.

Multiple ray casting modes are available such as Infinite, Scaled Vector or from segments with start/end points. The rays direction can be overridden from an attribute such as $Rotation.Up to ray cast using the origins input points' up vector allowing better control.

A new Create Points Sphere node has also been added with different options such as geodesic, poisson or angle based distribution, allowing to build easy ray cast logic.

Additionally, all ray cast related nodes (World Raycast, World Ray Hit Query, etc) can now query more attributes from the ray-hit result, such as UVs, Impact Normal, Render Material, etc.

Pathfinding

Pathfinding node adds support for A* pathfinding search algorithm across a point data.

When provided with point data to traverse, the pathfinding will search for points within a given search radius and if possible, find a complete and optimal path from the start position to a goal position, using the A* search algorithm. A heuristic (estimation) is used to predict the next point along the path, which can be adjusted to improve performance, at the cost of the path no longer being guaranteed optimality.

The final path, if it exists, will be forwarded as an output either as a Spline Data or a Point Data containing an ordered set of points to represent the path. If no final path is possible, there is an option to output a partial path as well.

Optional ray cast test can be done between each step to prevent the path from going through physical obstacles as well as attribute-based path selection weighting to help guide the search algorithm (i.e. favor flat surfaces over steep slopes).

Elevation Isoline

Added an Elevation Isoline extraction node that is able to efficiently build isolines from Surface Data such as the Landscape. This is useful for careful placement of assets near ledges and along slopes.

The output produced can be point or spline data per isoline with controls over min and max height, increment and resolution.

Write to Niagara Data Channels (Experimental)

A new Write to Niagara Data Channel node has been added to PCG to send data directly to a Niagara System.

By writing PCG attributes into an NDC, the associated Niagara System can spawn emitters or use the data as inputs for the system itself. This can be used for contextual spawning at runtime based on the PCG logic such as placing emitters under specific spawned assets, creating world ambiance systems or even adding emitters on the fly to a single system using PCG's runtime hierarchical generation and NDCs islands.

The Procedural Content Generation Framework (PCG) - Niagara Interop plugin must be activated to use this feature.

More information about Niagara Data Channels can be found here.

Save to PCG Data Assets

Save to PCG Data Assets node saves the input data collection to a PCG data asset directly from the PCG Graph execution it is placed in. It can open a dialog or save to a predetermined location.

Will rerun every time the graph is rerun, but will not execute if the inputs are the same. Can specify a description and a color as well.

Useful to build graphs that gather information offline to be consumed by other graphs as PCG Data Assets.

Additionally, it is now possible to export each data or the entire data collection directly from within the Attribute List View window in the PCG editor. Helpful for exporting on the fly for debugging or to compare data side by side outside of the graph execution context.

Builder Settings and Build Menu

A world partition builder that can generate PCG components in a level and save the results was added in the previous 5.4 release.

5.5 introduces a new PCG Builder Settings asset which allows specifying builder settings without having to pass a long list of arguments to the builder. The PCG Builder Settings assets can be created directly in editor from the PCG Content Browser menu and then customized.

The asset can be:

• Passed as a builder argument with the -PCGBuilderSettings=/PathToAsset switch

• Set as global Project settings

• Defined when triggering a PCG Build for the current loaded level using the new Build - PCG menu directly from editor

Additional Nodes and Operators

On top of the new Custom HLSL, Grammar, Spline and Segment manipulation, Geometry, Raycast, Isoline, Pathfinding, Spline Meshes, Save to PCG Data Assets, Write to Niagara Data Channel operators, 5.5 also introduces multiple native PCG elements including:

• Attract: interpolates points and attributes from a source data to a target data according to the weight value and attract distance. Useful to regroup points or interpolate attributes such as scale or rotation to a nearby center of attraction.

• Collapse: merges points and attributes according to an iterative search distance threshold. Useful to combine nearby points and use paired with the Attract node.

• Blur: Apply spatial blur on a given attribute within a given distance

• Cluster: Using traditional clustering algorithms, the Cluster node attempts to identify groups of points from a point data that share proximity to "centroids" in world space.

• Random Choice: Chooses points or attribute set entries randomly through ratio or a fixed number of entries.

• Create Points Sphere: Generates a sphere of points based on a sphere generation mode (Geodesic, Angle, Segments, Random, Poisson)

• Add Component: Adds a component per input point to the specified actor (either through an attribute on the ‘Target Actor’ data, or will default to the owner of the PCG Component), from a template component, or from a class stored in an attribute.

• Get Attribute List: Returns an attribute list per input data containing one entry per attribute. Options to also output the internal type and the default value (as a string).

• Bounds from Mesh: Updates the point bounds on the input data based on the bounds of static mesh(es) provided in an attribute.

• Create Collision Data: allows to create a data that works as-if all points were static meshes with their collision. The output data is a primitive data type (compatible with the volume sampler) and can be used as the "difference" part of the difference node for more precision.

• Spawn Spline Component: spawns spline component per spline data provided as input.

• Wait Until Landscape Ready: Waits until landscape changes (if any) are done. This node, in collaboration with the options on the graph/pcg component that ignores landscape updates (e.g. Ignore Landscape Tracking option), allows to build graphs that would affect the landscape (such as placing actors with landscape patches, etc.) without creating loops.

• Attribute Remove Duplicate: remove points or attribute set entries which have identical attribute(s) values.

• Get Tags: Returns an attribute list per input data that contains one entry per tag, with optionally the values (as strings).

• Data Tags to Attribute Set: Returns an attribute set with a single entry per input data.

• Sort Data by Tag Value: Sorts input data based on their tag values, e.g. when they have tags of the form Tag:Value, in either ascending or descending order.

• Filter Elements By Index: Filters a points or attribute sets directly getting new data with specified indices.

• Parse String: Parses string as attribute and converts it into a compatible PCG type.

• Octree spatial queries: adds new functions to do spatial queries from the Point Data octree in Blueprint

Platform

Editor Preview

Editor platform preview allows artists to iterate on content (materials, VFX, etc.) in UE Editor and preview the visual that they would see on device. Unreal Engine 5.5 brings several improvements to help with content development for mobile games.

• Connected Android device profile capture, to allow previewing a specific device

• half16 float precision shader emulation, for materials which require it

Mobile Renderer

Unreal Engine 5.5 brings several new features to the mobile renderer:

• Forward mode now supports d-buffer decals, rect lights, capsule shadows and point light shadows

• Runtime automatic PSO precaching, which offers an alternative to the manual PSO gathering workflow

• Screen-space Reflections

XR Resolution Scaling

Resolution scaling in XR has been updated to better match the rest of the engine, and allow new upscaling modes which take advantage of the ability to perform upscaling within the OpenXR compositor (behavior may vary depending on OpenXR runtime).

• vr.PixelDensity has been renamed to xr.SecondaryScreenPercentage.HMDRenderTarget to reflect the fact that it can only be used for spatial upscaling and should not be changed frequently at runtime. This makes it analogous to r.SecondaryScreenPercentage.GameViewport on desktop. In XR, the desktop CVar is disabled, and you should use xr.SecondaryScreenPercentage.HMDRenderTarget instead. Additionally, "100" is now the standard value corresponding to the HMD’s ideal render resolution, rather than “1.0f”.

  • xr.SecondaryScreenPercentage.HMDRenderTarget works by changing the size of the final render target and allowing the result to be automatically spatially upscaled/downscaled by the OpenXR compositor. This can be performed even when post-processing is not available, like when using the Mobile renderer with Mobile HDR off.

• Unreal Engine can also now support Dynamic Resolution in XR even when post-processing is not available, like when using the Mobile renderer with Mobile HDR off. You can enable this feature with the CVar xr.MobileLDRDynamicResolution. Note that in order to use dynamic resolution, you must also enable it as you would normally, and it must be supported by your XR device via its device-specific UE plugin.

visionOS 2.0 (Experimental)

Experimental support for visionOS 2.0 and Mixed Immersive Mode which enables passthrough support with Metal.

See the Apple Vision Pro Quick Start Guide.

Mobile Forward and Desktop Forward feature parity

The Mobile Forward renderer is receiving feature updates and performance improvements with the objective of becoming the recommended renderer for PC VR once it reaches feature parity with the legacy Desktop Forward Renderer. In 5.5 we implemented support for the following features:

• Moveable Point/Spot-light IES Textures

• Capsule Direct Shadows

• Decals

• Rectangular Lights

• Volumetric Fog

• Niagara Particle Lights

• Moveable Point Light Shadows (only supported with d3d and not Vulkan)

Audio

Audio Insights

Audio insights is our major tool for profiling and debugging audio. In this release we are providing a standalone mode and additional visual debugging improvements, such as:

• Standalone Audio Insights mode for remote connections

• High-frequency Plotter data

• Saving Tab layouts

Audio Widgets

Fancy Audio Widgets are a big thing in the Audio world. Customized, slick and nicely dressed up UI are required because that is a widely adopted standard in the industry. We are improving our current widget system to make it easy to customize by providing a system to make custom audio widgets with a refined visual representation:

• Create extensible widgets based on UMaterials where designers can create custom UMaterials for common widgets.

• Provide base implementation of the UMaterial.

Things to consider

• Materials performance implications on UI performance.

• Proper integration to Metasounds.

MetaSounds Usability

This release brings numerous quality of life improvements to MetaSounds and Audio Modulation:

• New console commands

• Don’t need to click canvas before playing graph w/ spacebar

• Get Last Index helper node

• Improving convert from preset workflow

• Dropdown menu supporting arrow keys

• Add play/stop button to sound previewing

• Fast input promotion

• Simple-view options

• Hide unconnected pins

• Right-click create MS Source from CB

• Clear unused inputs

• Add getname to wave asset

• Clearing delay line audio

• Find-in-references support

• and many more

MetaSounds Pages

Allows swapping out a MetaSounds Graph or Default Properties depending on platform targets.

• Supports presets

• Can customize inputs, properties, per platform

• Previewing pages and page fallback schemes in-editor

• Can create dramatically simpler/cheaper graphs on lower-end platforms without changing gameplay

MetaSounds Relative Render Cost

When multiple or relatively large MetaSounds play concurrently, they can require significant CPU time. On limited platforms, when MetaSounds uses a large CPU budget, it has knock-on effects to other game systems because of CPU bottleneck. MetaSound Relative Render Cost will allow the effective "Voice Count" of a MetaSound to more accurately reflect the true rendering cost of a MetaSound by using the dynamic voice count. On limited platforms we should see that large MetaSounds count for multiple voices and effectively reduce the number of concurrent waves being decoded at the same time.

• Step toward intuitive performance metrics

• Can better cap CPU

• Platform/CPU independent metric

Notes

Voice limiting enablement is done via

• CVAR au.EnableRelativeRenderCostVoiceLimit 1

• The MetaSound editor will show the relative render cost in the lower left corner when a metasound source is played.

• The debug HUD for au.debug.soundwaves 1 shows the relative render cost (RRC) next to the CPU usage.

Modeling

Modeling Tools (Beta)

Modeling tools in Unreal Engine 5.5 offers the following improvements:

• Weld and Collapse

  • Weld now welds to center. A new "weld to" tool will weld to last selection.

  • Edge collapse allowed in more cases, such as closing single-triangle holes.

  • Weld and bridge can be run on multiple group edges at the same time as long as they can be partitioned into two separate sequences.

  • Weld, bridge, and collapse can work on vertex selections if they can be converted to appropriate edge selections.

  • Weld can also weld a pair of vertices, and collapse can work with a face selection.

• Transform and Align: Now work on any primitive component, in addition to the mesh types.

• Edit Pivot Point: If the Edit Pivot tool is run with an active geometry selection, it now initializes the pivot location to the selection (just the location, keeps the default orientation). It also now supports snap-dragging just the orientation.

• Sculpt: When the stylus and tablet plugin is enabled the Vertex and Dynamic sculpting brushes will support pressure for brush strength.

• Split Tool: The split tool now can show a preview of how it will split your meshes, and has new options to split by polygroup, material ID, or with a vertex distance tolerance to allow you to not split across un-welded boundaries.

• MeshToCollision: The mesh-to-collision tool UI now has an explicit option for convex decompositions (previously it was hidden as a setting under convex hulls) and defaults to using the new navigation-driven algorithm (though you can still switch to the old method and/or manually request a number of hulls).

• PolyCut: Polycut now has a 'cut outside' option.

• Primitive: New Capsule tool, support changing the number of slices along the cylindrical section.

Extrude polygon, extrude path, and revolve path now initialize their draw plane from the user selection, including the geometry element selection (if available) so you can start drawing your new shape aligned to the selected vert/edge/face.

• CubeGrid: If run with an active element selection, initializes from the pivot location (like edit pivot, keeps the default orientation).

To learn more, see the Modeling Mode Overview.

Modeling Workflows (Beta)

Selection Conversion: mesh element selection conversion cover all cases, so selections are now consistently preserved/converted when the selection type changes

Mesh Element Selection Colors: The mesh element colors have been updated. The color settings are now customizable in the project settings

To learn more, see the Mesh Element Selection documentation.

UV Tools (Beta)

• Brush/paint UV Selection Tool: Works in both the 2d and 3d viewports, and has an option to brush an island at a time.

• "Make Island" Operation: Takes the selection and makes it into a separate island (i.e. removes all seams inside the selection, and creates seams along its boundary). Combined with the brush tool, it makes it possible to create islands in cases where bad topology previously made it very hard to draw seams.

• Transfer UVs Tool: In the modeling tools UV section. Transfers UV values from a mesh that has been simplified using the "Existing Positions" method to the original mesh, allowing UV layout to be done on a simplified mesh and then moved back to the original high-res mesh.

• New Layout Options: There are new options to maintain scale or rotation when repacking islands

• Export UV Snapshot: The bake UV snapshot is now available in the UV Editor and baking tools. This allows for the export of an image with user controllable colors aspects of the wireframe display.

To learn more, see the UV Editor documentation.

Texturing Tools (Experimental)

• New Nodes

  • Histogram Scan

  • Histogram Range

  • Edge Detect

  • Warp

  • Texture Path

• Improved Default Material in 3D Preview: The new material provides open slots for standard material channels like BaseColor, Roughness, Normal, Specular and Metallic.

• New Export Mode: The new Export Texture Graph mode allows you to use texture graphs as reusable utilities with exposed input/output parameters without the need to view the entire graph.

To learn more, see the Getting Started with Texture Graph course.

Geometry Scripting

Dynamic Mesh Components also now support Static Draw Path and Distance Fields in their rendering options, and can be used with Lumen (though their lumen mesh cards will be simpler than the static mesh equivalent).

Over fifty new geometry script nodes were added to the Geometry Scripting library in more than a dozen functional categories. For example, this release provides additional interoperability with skeletal meshes including morph targets, skin mesh profiles, bone weight functions, and LODs. In addition, we added several new functions to aid with collision objects on meshes and convex hull decompositions. We added a wide range of mesh specific functionality, ranging from mesh selections, mesh repair to mesh UV packing. To simplify working with pooled temporary dynamic meshes, we added new macros to request and release meshes.

To learn more, see the Geometry Scripting User Guide.

Content Pipeline

Import Interchange Framework

Interchange Framework provides users with easier ways to create, extend and parameterize import/re-import, and soon export, workflows.

In 5.5, with completion of features on level import and some UI updates, the Interchange is now considered production ready for asset imports and beta for level imports. Level import will create assets and spawn the hierarchy of the model into the level.

The work focused on:

• Finalizing the pipelines for level import, especially with regards to the FBX file format. Content creators can now fully customize their FBX pipelines using the Interchange Framework.

• As output of the level import there is a new option to create a level instance actor.

• The collision UI and behavior was reworked, especially around reimport.

• Some cosmetic changes were introduced in the import dialog window.

Interchange Workflow Improvements

Expansion of Interchange features:

• Add editor only blueprint pipeline to access editor functions in custom pipelines;

• Work on animation and morph targets on skeletal mesh;

• In MaterialX import, add support for some boolean and custom inputs;

• In glTF import, add support for anisotropy extensions and extras;

• node related metadata are now stored on actors.

Customize USD Asset Import with Interchange (Experimental)

USD is a versatile scene description file format with a growing adoption across the 3D industry.

USD was added to the list of file formats supported by the Interchange framework. Content Creators benefit from more control over the import process and are now able to add custom processing steps for asset import of USD files, similar to the Interchange capabilities that are already available with other formats such as FBX.

The support for USD through Interchange is considered Experimental and limited to import of assets. The supported asset type are:

• Texture

• Material

• Material Instance

• Static Mesh

• Skeletal Mesh

• Anim Sequence

USD Support and Performance

USD is a versatile scene description file format with a growing adoption across the 3D industry. It is used by content creators, artists to transfer 3D content, especially scene description, between DCCs. Originally used in the media entertainment industry, its use is now spreading to games and other industries like automotive, architecture, etc.

In 5.5 major work has been done to reduce import/load times and memory footprint for very large stages, especially the ones using a lot of instanceables. This will show in use cases of load/reload stage actor as well as regular imports. This enhances QoL by speeding up iteration on scenes and by allowing stages to be loaded on a broader range of machines, especially those with lower memory capacity.

A collapsing API provides finer control on what elements are collapsed when loading/importing in UE.

Framework

State Tree UX and Events

In this release the State Tree editor got a large UX revamp, introducing more eye-catching colors, icons and accessibility options. We also added a new Outliner window to help navigate large trees quicker.

We improved event support for conditions, adding the option for payload structs. This can for example be used for type of damage done and amount, or loudness and location of a noise event.

State Tree Runtime

To help with richer state selection we have added 2 new State Selectors:

• Utility State Selector (Score based selection)

• Random State Selector (uniform and weighted).

We have also added support to run parallel tasks by offering the ability to run sub trees in parallel to the main one.

Finally, we have added property binding functions, allowing users to perform calculations on values being sent to a property. This is useful to combine and perform calculations on other parameters or external references.

To learn more about the State Tree Selectors, read the State Tree Selectors Overview documentation.

State Tree Diff Tool

As big teams with multiple members collaborate to create more complex AI systems using the modular State Tree features, we needed a better way to visualize diffs for the State Trees so users can be more efficient with such shared data. Just like the blueprint diff tool that came before it, the new tool is better suited for this format to review work and easily identify added/modified/removed content to speed up the team's reviewing and debugging workflows.

Gameplay Cameras

Coordinating cameras in Unreal Engine has never been easier. We are aiming to provide a new workflow, with tools and data assets which try to make multi-user camera auditing a reality by splitting the system into multiple, logically organized files. Users should be able to easily author new cameras modularly, as a team, and integrate them into the system that will handle transitions between the different setups in a very flexible and streamlined way. Our toolset will ensure that debugging cameras will be easier than ever, as we are making the system and debug tools compatible with rewind debugger.

To learn more about the Gameplay Camera System, read the Gameplay Camera System documentation.

Struct Utils

Struct Utils plugin was originally introduced with Unreal Engine 5.0. Since then it has seen regular quality of life improvements and is now considered production ready and will be fully supported moving forward. Struct Utils has also been moved into the engine module and is no longer a separate plugin.

Instanced Actors

Instanced Actors is a new feature designed to reduce the overhead of having too many actors in your game world. It does so by replacing actors with Mass entities and converts on-the-fly between actors and entities (called hydration/dehydration), providing a lot more performance out of densely populated open world environments. The conversion is controlled by the Mass LOD system using distance to viewer logic, and physics traces can be used to trigger hydration as well.

This works best when you have many actors using the same mesh, for example rocks and trees in large environments.

Automatic Navigation Link Generation

Unreal Engine 5.5 features a way to automatically generate short distance navigation links.

• When enabled, navlinks are generated as part of the navmesh tile generation process by reusing the navigation collision data.

• Navlink trajectories are configured to respect specified length, height and other parameters.

• The trajectories are also validated to be without collisions while respecting the agent radius.

• Generated navlinks can be discovered and handled during path following in a similar way to custom links, by using a UGeneratedNavLinksProxy class.

Debug:

• Debug display options can show the navlinks trajectory and trajectory validation.

• An option allows to show links that were filtered out.

• A specific edge can be inspected and this allows us to see the steps used by the generation.

• Generated links are displayed with other navlinks but using a thicker line.

• Navlink build time is displayed with other navmesh build time statistics.

To learn more about automatic navigation link generation, read the Automatic Navigation Link Generation documentation.

Mover Plugin - Animation Support

As we keep developing and making our new character mover better, we are making strides to keep pace with the latest and greatest UE5 animation technologies, including Motion Warping, improved Animation Root Motion support, and trajectory queries for Motion Matching.

Learning Agents

Learning Agents is a UE plugin that allows game developers to train and deploy bots using Reinforcement Learning and/or Imitation Learning.

Changes from 5.4 to 5.5:

Re-Architect ML Training Code

• Rewrote the ML training code such that users have more control over the networking protocols and ML training algorithms

• Networking protocols now accept a variable number of networks & data buffers in support of BYOTA

Support Additional Networking Protocols

• Learning Agents now has the flexibility to support multiple networking protocols.

  • TCP Sockets - good for communication over a local area network (LAN)

  • Shared Memory - great for fast communication on a local machine

• End users can extend LA’s networking by adding their own external trainer protocol

Bring Your Own Training Algorithm (BYOTA)

• Rewrote the python side of Learning Agents so that it is easier for users to integrate off the shelf ML training algorithms or custom python training code

• Users can make these changes directly in their project workspace without needing to modify Learning Agents’ codebase

Mac and Linux Training Added

• Training now works on Mac and Linux!

• Linux currently supports both shared memory and socket networking protocols, while Mac currently only supports sockets.

Editor and UI Systems

Enhanced Text Rendering in UMG

This work will enhance both visual fidelity and rendering performance for fonts, with the following Text Rendering Features:

• Fonts can now be scaled without losing clarity. This means that text will appear crisper at different sizes.

• Higher quality effects such as outlines and drop shadows by using distance fields in materials.

• Reduced memory usage at runtime.

Scriptable Tools

• Modular Behavior: We added a new Modular Behavior based tool to replace the 5.4 click and click drag based tools.

• Tool Builders: Added support for tool builders with both tool target and custom tool builder support.

• Filters and Collections: Added support for tool group filters to manage large tool collections.

• Point/Line/Triangle Sets: Added support for point/line/triangle sets, allowing persistent drawn objects compared to the legacy primitive drawing support in the Render event.

• Widgets: Added support for Blueprint scripted viewport widgets, allowing more customization in UI for the tools.

• Mouse Behaviors: Added support for multi-click, single click, double click, click drag, click or drag, mouse hover, mousewheel ITF behaviors within the Modular Behavior tool base.

• Input Behavior: Added support for single/multi-key input behavior to the ITF and also exposed support in Scriptable Tools.

To learn more, see the Scriptable Tools System documentation.

Additional Plugin Directories

Users can now specify directories outside of the engine and project to parse for plugins directly from the plugin browser! Plugins found in these folders will appear in the browser just like any others. Use this feature to maintain a dynamic library of tools that can be updated in one central location and referenced by all of your projects.

Batch Renamer

Previously released in 5.4 as "Advanced Renamer," this plugin has been re-released for 5.5 under the new name "Batch Renamer" and will be part of the core UE Editor experience. This plugin allows users to rename multiple assets and actors and add prefixes/suffixes simultaneously. In 5.5, the Batch Renamer's UI has seen a few updates to look coherent with the UE5 styling.

Reference Viewer UX Enhancements

Users can now right click on Referenced Nodes and select the "Resolve Referencing Properties" action in order to visualize which properties are referencing that Node from its Referencing Node. This option is currently retrieving properties when they use the Node Asset both as Reference/Value or as Type.

In the future we might also show information for specific types (Materials, Fonts, etc), e.g. the names of Material Parameters referencing a Texture.

The Reference Viewer also received a few usability enhancements that will improve the content refactoring experience :

• Collapsed nodes are now easier to spot when zoomed out, and we no longer collapse when there is only 1 reference

• Settings in Editor Preferences are now respected

• Loading a large graph no longer stalls the editor

StylusInput Plugin

The plugin supporting pen and tablet input has been rewritten. Its new API is more explicit, robust, and performant due to the following:

• Tablet input contexts need to be explicitly requested for individual windows. This ensures that tablet data is only generated when it is actually needed, and that an application/plugin only receives the tablet data it needs.

• Tablet device data gets forwarded directly as a stream of packets, and any state management is left up to the client code. This avoids issues experienced in the previous implementation of the plugin where packets were dropped or performance was inferior when there was load on the overall application due to tablet data only being evaluated during a tick.

• Users of the plugin can choose if callbacks for new tablet data are made on the game thread or on an asynchronous thread. Getting the data on the game thread avoids having to do any thread synchronization for most use cases, whereas asynchronous calls are potentially more performant and/or result in lower latency for the end user.

The StylusInput plugin currently only provides tablet data for Windows platforms with Windows Ink support. Support for Linux and Mac is planned for future releases. Furthermore, while the plugin forwards mouse input, this is again only available on Windows platforms with Windows Ink support. A fallback for mouse input only on all platforms is planned for UE 5.6.

Media

Media IO Holdout Composite for Video and Emissive Materials

In past releases, we added a contextual menu to the Media Plate Actor called Overlay Composite Material that helped with TSR smudging artifacts. We are deprecating that and instead releasing a new Plugin and Component called Holdout Composite that offer the following improvements:

• Bypass TSR and tone curve for video/media plates: avoid smudging artifacts due to lack of motion vectors and (sometimes) undesirable color transformations.

• Works with translucency objects in front. This was not the case with the previous implementation.

• Opt-in/out exposure compensation, meaning video content can be affected or not by real-time Eye Adaptation.

Constraints

• For Unlit materials only.

• Requires Alpha Output & Support Primitive Alpha Holdout project settings.

• Translucent videos not supported yet.

Media IO Timecode Track Support

We are adding Timecode support to ImageMediaSource and FileMediaSource video assets so they can now properly be placed and used in Sequencer. The Timecode metadata can be set via a manual field for image sequences and parsed through the MOV container for standard video files.

• Add support for and expose Timecode track to Sequencer.

• Add Timecode support :

  • ImgMediaSource (editable field)

  • FileMediaSource (through the MOV container Panel)

Production Rendering Pipeline

Movie Render Graph (Beta)

Building on the successful experimental launch of Movie Render Graph in Unreal Engine 5.4, the new graph-based configuration workflow continued to be the main priority. New development is split evenly between new workflow improvements enabled by the graph configuration, refinements based on initial user feedback, and improved parity with the legacy preset configuration. Unreal Engine 5.5 will include the following:

• Spawnables in Collections.

  • Transient Actors can be referenced by name, eliminating additional setup overhead for scenes with Spawnables.

• Improved Console Variable Management.

  • Configure overrides in the Queue window without reopening the graph.

• Set Start/End Console Commands.

  • Trigger logic (ex. from Blueprints) that relate to the render.

• Improved 32-bit Post Process Material Support.

• Script Tags to facilitate pipeline tools and scripts.

  • Scripts can parse graphs to find particular nodes they may need to access/modify/etc. more easily.

• Reference Motion Blur is available on the Path Traced Renderer node.

• Render All Cameras is available on the Camera Settings node.

Render Layers for All Asset Types

In the experimental launch of Movie Render Graph, some critical Actor types lacked the ability to be used as a Holdout or some/all of the other options found in Modifiers. In Unreal Engine 5.5, baseline support for all Actor Types will be available, which now includes:

• Translucent Objects.

• Niagara FX.

  • Via support for Translucent Objects.

• Heterogeneous Volumes.

• Landscapes.

• Sky Atmosphere without a Sky Sphere.

  • Render Layers initially supported Sky Atmosphere only with a Sky Sphere but this is no longer required.

Custom EXR Metadata

Unreal Engine 5.5 has a new Set Metadata Attributes Render Layer node that allows users to configure custom attributes that will be written as EXR Metadata when rendering to that Output Type. Metadata Attributes are user-driven key/value pairs that expand upon the default metadata (ex. GPU, driver, memory usage, etc.) provided at render time. Users can use slashes to create organizational structure for metadata and File Name Format tokens for dynamic metadata.

This node is also scriptable and pipelines can automate metadata creation by adding nodes via Python, alleviating the need for custom tools to interject metadata after the EXR is written.

Avid DNxHR/Apple ProRes in Graph

Apple ProRes Movie and Avid DNxHR Movie will be available as Output Type nodes in Movie Render Graph. These two nodes have improved functionality in the graph, offering a new Quality property that gives the artist the standard set of options for each codec. In the legacy preset system, the quality was hardcoded to a specific value that the user could not modify.

Both formats also now properly embed timecode from Sequencer for improved editorial interoperability.

Cryptomatte/Object IDs in Graph

ObjectIDs will be available as a Renderer node in Movie Render Graph in Unreal Engine 5.5.

Protocols

DMX

Alongside GDTF and MVR integration at the core of the plugin, DMX tech stack including Control Console, Pixel Mapping and Conflict Monitor is now Production Ready for live show designers, virtual production operators, anyone desiring to use DMX to drive in-editor elements for real-time preview.

Control Console Cues & UX

• Cues so that users can store & load multiple Control Console configurations.

• Editor docking for better UI integration.

• GDTF support and integration for reading default and physical fader values, adding a third option to Faders:

  • DMX

  • Normalized

  • Physical

Pixel Mapping Color Accuracy

Adding support of Transfer functions (linear, sRGB, custom 2.2/2.4 gamma curves) along the output Color Space settings.

Data Conflict Monitoring

• Show objects that send DMX even if they do not cause a conflict

• Option to navigate to objects sending DMX

• Option to open objects sending DMX

• Performance stats relevant for large quantities of DMX data sent to the network

Remote Control DMX Patching System Integration

Adding the Signatures to Remote Control. Similar to the DMX Fixture Types, Signatures are a collection of exposed properties and allow users to quickly repeat the process to a large quantity of Actors. Previously, users had to define Universes and Patch ID's manually for every property but now once signatures are created and Actor properties exposed, they can also be Patched and saved in a DMX Library for further control.

Remote Control DMX Patching System Integration is about providing a mechanism that feels natural and coherent with the current DMX tech stack so that Remote Control can be used to control arbitrary UE Actors with DMX.

This feature is for Virtual Production, Live Events or anyone wanting to use DMX to control arbitrary Actors in UE.

While Signatures are inspired from DMX, the concept can be used for other protocols for improving the time taken to expose properties to Remote Control.

• Signatures to quickly apply similar set of exposed properties to Actors

• DMX Library for Patching and GDTF/MVR export

• Revised UX for improved usability, not only for DMX workflow

• Improved performance when driving large sets of properties

Platform SDK Upgrades

• Windows

  • Visual Studio 2022 v17.10 or newer

  • Windows SDK 10.0.22621.0 or newer

  • LLVM clang

    • Minimum: 18.1.3

    • Preferred: 18.1.8

  • .NET 4.6.2 Targeting Pack

  • .NET 8.0

• IDE Version the Build farm compiles against

  • Visual Studio 2022 17.8 14.38.33130 toolchain and Windows 10 SDK (10.0.22621.0)

  • Xcode 15.4

• GDK

  • Minimum Windows SDK: 10.0.22000.0

  • GDK: June 2024 Update 2

  • Latest recovery version

  • Supported IDE: Visual Studio 2022

• Linux

  • Native Linux Development

    • Recommended OS: Ubuntu 22.04, Rocky Linux 8 or newer, Redhat Linux 8 or newer

    • Compiler: clang 18.1.0

  • Cross-Compile Toolchain: v23 clang-18.1.0-based

• MacOS / iOS / tvOS / iPadOS

  • Recommended OS/Xcode

    • Latest macOS 14 Sonoma

    • Xcode 15.4 or newer

  • Minimum OS/Xcode

    • macOS 13.5 Ventura

    • Xcode 15.2

  • Beta OS/Xcode (See Note below)

    • macOS 15 Sequoia

  • Supported Target SDK versions:

    • iOS SDK version: 15

    • macOS SDK version: 13

    • visionOS SDK version: 1

  • iOS Graphics API: Metal 2.4 - 3.1

  • Other Notes

    • Shader Model 6 (SM6) requires macOS 15. This support is in Beta, and we do not recommend it for production at this time.

• Android

  • Android Studio Koala 2024.1.2 August 29, 2024

  • Android NDK r25b

  • Android SDK

    • Recommended: SDK 34

    • Minimum for compiling UE: SDK 34

    • Default target SDK for shipping: SDK 34

    • Minimum install SDK level: SDK 26

    • AGDE v23.2.91+ is recommended if you are using AGDE debugging, as this version contains a fix for a SIGBUS error.

  • Build-tools: 34.0.0

    • If you try to use 35.0.0, you may have issues if using aidl on Windows.

  • Java runtime:

    • openjdk 21.0.3 2024-04-16

    • OpenJDK Runtime Environment (build 21.0.3+-12282718-b509.11)

    • OpenJDK 64-Bit Server VM (build 21.0.3+-12282718-b509.11, mixed mode)

  • Other Notes

    • UE has been updated to use Gradle 8.7, and the Android Gradle Plugin (AGP) version we use has been updated to version 8.5.2. If you are using Android Studio for debugging, we recommend using Android Studio Koala. Ladybug also works, but do not update Gradle or AGP from the above versions.

    • When you choose your NDK level, you should target android-26, which supports Android 8.0+.

• EOSSDK

  • 1.16.4-36651368

• Steam

  • 1.57

• Switch

  • SDK 18.3.1

  • Minimum Firmware Version: 19.0.0-2.0

  • Nintendo Dev Interface 2.6.0

  • Supported IDE: Visual Studio 2022

• PS4

  • Orbis SDK 12.008.011

  • System software 12.008.011

  • Supported IDE: Visual Studio 2022

• PS5

  • Prospero SDK 10.00.00.40

  • System Software 10.01.00.00

  • Supported IDE: Visual Studio 2022

• ARCore

  • 1.37

• ARKit

  • 4.0

• OpenXR

  • 1.0.27

Release Notes

Animation

API Change:

• ILODSyncInterface's SetSyncLOD and GetCurrentSyncLOD functions have been deprecated in favor of functions that allow separate control over the LOD requested for streaming and the LOD used for rendering.

New:

• Added preview scene controller to animate character in any animation viewport using pose from any other running instance of the same skeletal mesh.

• Multiple skin weight profiles can now be activated at the same time and layered on top of each other. This is currently limited to two layers and the active profiles cannot have overlapping weights, on the same vertex, that differ from the base.

• The skeleton tree now has an option to show the internal bone indices.

• [AnimationCore] Expose EEulerRotationOrder as blueprint type, which should be the enum to use when it comes to rotation order across animtion systems, including control rig.

Bug Fix:

• Fixed an issue where an actor using the LOD Sync Component, such as a MetaHuman, would only ever use the lowest LOD if the project had LOD streaming enabled.

Deprecated:

• USkeletalMesh::GetHasBeenSimplified and USkeletalMesh::SetHasBeenSimplified have been deprecated and should no longer be used. This information is already stored per LOD and can be accessed with FSkeletalMeshLODInfo::bHasBeenSimplified.

Animating in Engine

New:

• Sequencer: Anim details: Shift does range select, and use new method to get display names to fix modular rig bugs with details panel

• Sequencer: Control Rig: Add option to have non-grouped channels still get sorted when other groups are present. This is needed for a request to get the Control Rig WeightChannel first in the outliner when active, otherwise to hard to find.

• Sequencer & Control Rig - Changed the default behavior when adding new control rig track: rigs added later now are evaluated after existing rig tracks by default, instead of before. The evaluation order can still be changed by right clicking on the Control Rig track and changing the order number.

• Animator Kit plugin - when Animator Kit plugin is enabled, it also enables the "New TRS Gizmo"(Gizmo Framework) plugin, which allow you to enable the new TRS Gizmo via "Editor Preferences - General - New TRS Gizmo - Enable New Gizmos"

• Sequencer: Anim Details: Add support for interactions and driven controls

• Sequencer: Add bake settings to load animation into section for control rig so you can do proper key reduce and keep controls

• Animator Kit Plugin - Added Sculpt Deformer Control Rig & Deformer Graph. Its implementation can be found in /Plugins/AnimatorKit/DeformerRigs/

• Sequencer & Control Rig - Control Rig asset picker no longer shows rig modules as they are not intended for sequencer usage

• Sequencer & Control Rig - Updated UI for the control rig asset picker when adding new Control Rig tracks. Also added asset filters based on ControlRigBlueprint Variant Tags. New tags can be created in Project Settings - RigVM Project Settings - Variant Tags. And these tags can be assigned to ControlRigBlueprints via Class Settings - Variant - Asset Variant.

• Sequencer: Anim Details: Show anim details for sequencer selected objects/components not editor selected, per animator feedback

• Sequencer: Add Force Evaluate BP/Python function to make sure we evaluate immediately, this is needed for example with control rig's since they get setup lazily on evaluation.

• Sequencer: Anim detail fixes: Added support for bool,integers, floats and doubles

• Sequencer Control Rig picker - It now shows rigs that can work with any skeleton, in addition to rigs created specifically for the active skeletal mesh when "filter by skeleton" is turned on

• Animator Kit Plugin - Added CameraSpaceLatticeDeformer Control Rig & Deformer Graph. It can be used to deform a skeletal mesh from the viewpoint of the "Camera Handle" control. This control can be constrained to a cine camera to allow for deformation control from the perspective of the cine camera. Its implementation can be found in /Plugins/AnimatorKit/DeformerRigs/

• Sequencer: Change default behavior so Control Rig Section to Keys are set based upon what section is selected in the outliner

• Sequencer: Linked Anim Sequences. Allow ability to specify custom range when saving out custom time range, includes BP/Python functions.

• Animator Kit Plugin - Added Lattice Deformer Control Rig & Deformer Graph. Its implementation can be found in /Plugins/AnimatorKit/DeformerRigs/

• Sequencer: Constraints working with snapper tool

• Sequencer: Fix overshoot for Smart and Auto tangents

• Sequencer: Control Rig:Can now run PIE and animate a Control Rig in editor window at the same time.

• Sequencer: Anim Details: Attributes are now shared per animators request, instead of just showing the first one.

• Sequencer: Fix so User/Broken tangents get set to curve slope automatically wherever added in Curve Editor or Sequencer. Need to make sure we only do this when within the keys, if a key is added outside it stays flat.

• Constraints: Space Switches: Add buttons to compensate key or all for spaces like we can for constraints.

• Sequencer: Anim Details: Per animator feedback we only select curves on the section to key section when there are multiple sections.

• Sequencer: Control Rig: New Smart Baking algorithm added as a curve filter, make new filter default for reducing control rig keys when baking, add bp/python support.

Bug Fix:

• Sequencer: Animation Baking in subsequences would get the incorrect time range.

• Sequencer: Anim Details: Fix Rotators not working with anim details and selection not working with actors.

• Sequencer: Tween tools: Fix divide by zero crash with new Push Pull tween and change blend to ease function based on animators feedback

• Sequencer: Control Rig: When collapsing, recording animation keys use preferred rotators.

• Sequencer: Anim Details: Group keying properties in anim details to one undo.

• Sequencer: Control Rig Make sure to tick the mode manager so pending deactivated modes are really deleted before enabling a new control rig edit mode.

• Sequencer: Control Rig: Fix crash after undo add rig then add again, need to remove the stale control rig node from the layer instance proxy

• Sequencer and Control Rig only reconstruct in the game thread #changelist validated #virtualized

• Sequencer: anim Details panel add support for constraints.

• Sequencer: Anim Detail Fixes, reset to default and vector3d working #changelist validated #virtualized

• Sequencer: Control Rig: Make sure when collapsing by key the key is in section range

• Sequencer : Anim Details: Make sure to set sequencer on edit mode and pass that through to tabs to avoid crashers

• Sequencer: Control Rig: Restore selection state when refreshing tree view and make sure to clear sequencer when selecting in viewport/outliner

• Sequencer: Control Rig: Fix collapsing sections when there are no absolute sections.

• Sequencer: Anim details: Fix slow selection due to details panel getting recreated too many times, use timer handle now to make sure we only tick next once.

• Sequencer: Anim Details: Use Relative values directly to avoid quat/rot conversions.

• Sequencer: Anim Details: Fixed anim details showing multiple curves with multiple actors

• Sequencer: Constraints: Only recreate channels if there is a valid world on the Control Rig.

• Sequencer: Control Rig: Disable control rig not letting other objects to key with 'S'

• Sequencer: Control Rig: Change the control mask from index based to be a set of names of masked out controls. Indices aren't reliable since the number of controls for rigs now changes for most rigs based upon how it is getting set up, e.g IK for FK settings now change the number of controls.

• Sequencer: Control Rig: Don't refresh bones transforms if post evaluating when restoring state.

• Sequencer: Control Rig outliner, speculative crash fix, reset delegate handles directly and check for null hierarchies

• Sequencer : Anim Details: Move updating values when we are dirtied to only happen on next tick so we only do it once instead of possibly thousands of times.

• Sequencer: Control Rig: Keep selection on IK/FK controls if selected and they lose visibility

• Sequencer: Control Rig: Don't reset the mask if we have zero available controls

• Sequencer: Constraints: Make sure to evaluate all constraints when baking

• Sequencer: Anim Details: Don't update if compensating

• Sequencer: Control Rig: When getting object replaced delegate don't force sequencer to rerun if the track is muted

• Control Rig: Rotation Orders: Fix various issues with rotation orders.

• FK Control Rigs: Fix channels keys not showing up on creation or load do to the track/section models not getting recreated. Need to mark as changed and wrap the change in a transaction for the view model to make the change. This will probably also fix some load time issues with AnimDataModels.

• Control Rig: Snapper: We had an optimization to not re-evaluate a snap if we are on the current Sequencer frame but that will break do to how we gather frames (we could have gathered the last frame most recently). So just remove that check.

Gameplay

New:

• Add experimental prediction to orientation warping

• Improved PoseSearchDatabase indexing performances that was causing stutters in databases with lots of assets

• [Motion Matching] Added sync groups support for the motion matching.

  • [Sync Groups] Added flag to stomp previous leader info (bOverwriteLeaderPosition).

  • [Sync Groups] Added a new role (ExclusiveLeader) which will make a tick record tick as ungrouped if it fails to be a leader.

• Expanded Motion Warping plugin to support non-Character actors using adapters, and added warping support to Mover plugin #virtualized

• [Motion Matching] Made PoseSearchDatabase items with an incompatible Skeleton have a red tint on their name to warn users.

• Added UPoseSearchLibrary::IsAnimationAssetLooping to gather animation asset looping state in a thread safe manner

• [Motion Matching] Added warnings for an empty PoseSearchDatabase item and an asset with an incompatible skeleton.

• [Motion Matching] PoseSearchDatabase item's asset picker now filters based on if the asset is compatible with the PoseSearchDatabase's schema.

• Improve debugging on OrientationWarp - Save prediction info so prediction can be analyzed during pauses

• Added UPoseSearchLibrary::GetDatabaseTags to gather PoseSearchDatabase Tags in a thread safe manner

• [Motion Matching] Able to perform all of the PoseSearchDatabase item's options via the right click context menu.

• Changed display name for UAnimNotifyState_PoseSearchBlockTransition from "Pose Search: Block Transition" to "Pose Search: Block Transition In"

• Made USkeleton::GetBlendProfile BlueprintThreadSafe

• Fixed blend profiles support in BlendStack anim node

• Improvements for motion matching debug lines rendering

• Introduced normalization groups to motion matching schema channels to be able to normalize them together

• Small performance improvements for motion matching

• Added PoseSearchDebugger support to scrub RewindDebugger recordings after PIE has been stopped

• Exposed PoseSearchAssetSampler to blue print via PoseSearchAssetSamplerLibrary

• Added initial motion matching support for AnimNext

Bug Fix:

• Fixed curves not being normalized from range 0 to 1 in FootAnimEventsModifier.

• Fix Orientation Warping Counter Compensate undoing root motion rotation.

• [Motion Matching] Fixed issue where selecting a BlendSpace, AnimMontage or AnimComposite for an item in a PoseSearchDatabase fails.

• Add a strong interp to Counter Compensate to address stuttering when correcting between two samples between the same frames

• Prevent Foot Placement running when an actor is dropped into the level viewport

• Fixed montage segment details ticking the scene in the widget instead of via the viewport client. This was prone to crashes when force ticking slate widgets.

• Fix to prevent Offset Root Bone anim node overwiting scale

• [Motion Matching] Asset browser refreshes its asset list when the target PoseSearchDatabase's Schema changes

• Fix Orientation Warping jittering with counter compensate - Don't update root motion direction based on prediction. - Remove threshholds / checks needed for contunity due to innapropriate root motion direction setting

• Fixed editor freeze when deleting a BlendSpace from a PoseSearchDatabase

• Fix Crash ChooserTableEditor due to 'SelectedColumn' not added to GC. - Add SelectedColumn to Root like 'SLevelEditor' does for 'SelectedElements'

• [Motion Matching] Added content browser to the PoseSearchDatabase Editor.

• keeping numerical errors in check in FAnimNode_OffsetRootBone::Evaluate_AnyThread

• Fix for UPoseSearchDatabase::CachedAssetMap garbage collection

• Fix for crash in UBlendSpace::ResetBlendSamples when adding a blend space into a pose search database

• Fix for BlendSpace playback in BlendStack when repurposing an anim player previously playing a sequence

• Fix for PoseSearch and Cook determinism by removing unneeded UPoseSearchSchema::PreSave

• Fixed motion matching trajectory generation when gravity and collisions are applied

• Fix for compatible skeletons support in pose history

• Fix for crash during blue print compilation containing FAnimNode_PoseSearchHistoryCollector_Base with bInitializeWithRefPose set to true

• Fixed ConditionalPostLoad dependency to UMirrorDataTable for motion matching

Deprecated:

• Deprecated UPoseSearchDatabase::GetAnimationAssets

• Deprecating FMotionMatchingState properties ComponentDeltaYaw, ComponentWorldYaw, AnimationDeltaYaw

Movie Render Queue

New:

• New: Added the ability specify cvars at the job/shot level for graph-based configurations. These cvars will override any cvars set within the graph.

• New: Added the "Is Spawnable" query to graph collections.

• MovieGraph: Added support for 32-bit output on additional post-process materials.

• New: Added the ability to frame nodes within the graph, or zoom out to show the entire graph (included in the View menu).

• New: Added drag/drop capability for most collection queries in the graph.

• MRG: Reference Motion blur should enable Reference DOF Post-processed Depth-of-Field does not work well if the input is already motion blurred. When using the reference motion blur mode, automatically turn on reference DOF.

• New: Added the ability to re-order graph variables (drag/drop) and assign them to categories. The categories themselves are also re-orderable. The variable order/categorization is reflected in the job variables in the queue UI.

• New: Added the "Avid DNxHR Movie" node to the graph. Note that this requires the "Avid DNxHR/DNxMXF Media" plugin to be enabled.

• New: Added two new timecode properties to the Global Output Settings node ("Custom Timecode Start" and "Use DF Timecode if 29.97 FPS"). These properties affect the timecode that's included in the output from the Avid DNxHR Movie and Apple ProRes Movie nodes, and also the burn in that's displayed in the default burn-in widget with the Burn In node.

• New: Added the "Apple ProRes Movie" node to the graph. Note that this requires the "Apple ProRes Media" plugin to be enabled.

• New: Added support for the Object ID pass (aka Cryptomatte) to the graph via a new "Object ID" node.

• New: Added the "Set Start/End Console Commands" node to the graph.

• New: Added a "Set Metadata Attributes" node to the graph, which adds metadata to graph output files (currently, only EXRs will pick up the metadata).

• New: Added the ability to duplicate a condition group condition in the graph.

• New: Updated the "Actor Name" condition in the Collection node to match spawnable actors. This is a side-effect of an update to spawnables in general to give them a more readable name when being spawned.

• New: Updated the picker for the Actor collection query in the graph to include a checkbox selection mode.

• New: Updated pinned property promotion to set the new variable's default value to the current value of the property.

• New: Added the "Actor Layer" query to graph collections.

• Added the "Data Layer" query to graph collections.

• New: Updated the Set Console Variable node to make promoting the Value property more streamlined. The "Value" in the context menu includes the name of the cvar -- eg, "Value (r.SomeCVar)". Also, when promoting the "Value" property, the new variable is given the name of the cvar.

• New: Added a new "Script Tags" property to nodes in the graph to allow for easy identification within scripts.

• New: Updated the Post Process Materials property to include an additional "Name" field (optional) that will be used as the pass name in file name formatting (the {renderer_sub_name} token in the graph, and the {render_pass} token in legacy MRQ). If a custom Name is not provided, the entire PPM's name name will be used.

• New: Updated the "Apply Console Variable Preset" node to allow per-cvar pin promotions (so individual cvars within the preset can be overridden easily).

• New: Added the ability to drag a pin to the Inputs/Outputs nodes in the graph and have the input/output created automatically (rather than creating the input/output manually, then doing the connection).

• New: Added the ability to enable/disable individual collections within a "Modifier" node in the graph.

• New: Added tooltips throughout the graph that specify a variable's description (in the Members panel, the variable node and variable node pin, and the queue UI).

• New: Added "Duplicate" for variables in the graph.

Bug Fix:

• Bug Fix: Fixed a freeze that could occur when using the Command Line Encoder node with a sequence that is playing audio.

• MovieRenderPipeline: Fix broken EXR channel names on linux

• Bug Fix: Fixed a crash that could occur if the queue has contents removed while a render is occurring. Removing queue contents is now blocked during a render.

• MRQ: Fix tiling logic to allocate history per tile. The code could result in excessive memory allocations in this case.

• Bug Fix: Fixed an issue that caused undo to reset the selection in the graph.

• Bug Fix: Fixed an issue that caused the sublevel picker in the Collection node to load all sublevel assets, causing lengthy freezes in large projects. The picker will no longer trigger asset loads.

• Bug Fix: Removed support for the "Buffer Visualization" view mode on the deferred renderer node in the graph because it could cause a crash.

• MovieGraph: Removed reliance on cvars for the (deferred renderer) 32bit setting on additional post-process materials, allowing per-layer support.

• Bug Fix: Updated the graph's preview window to hide burn-in and widget render layers.

• The Command Line Encoder node no longer requires the executable (specified in Project Settings) to be part of the project if the path isn't absolute (PATH will be searched).

• The Command Line Encoder node no longer generates incorrect warnings about missing {shot_name} and {sequence_name} tokens.

• The Command Line Encoder node now handles sequence-level encodes correctly (ie, the file name format excludes {shot_name}).

• Bug Fix: Updated the "Editor Folder" collection query in the graph to traverse into subfolders.

• Bug Fix: The autowire context menu in the graph is now restricted to nodes that can only be connected on that branch type or pin type.

• Bug Fix: Fixed a crash that could occur when Save As'ing over an existing graph that's already open.

• Bug Fix: Fixed a bug where the C++ add-node API (UMovieGraphConfig::CreateNodeByClass()) didn't work properly when called from Python.

• Bug Fix: Fixed several quirks in the file name format autocomplete widget.

• Bug Fix: Fixed the detail lighting mode (via View Mode Index) not properly working on the Deferred Renderer node.

• Bug Fix: Updated the lighting components on the path tracer node to work properly. Previously they were exposed under Show Flags which did not work properly. A dedicated Lighting Components section was added, which instead affects the post processing volume's path tracing Lighting Components properties.

• Bug Fix: Updated the "Write All Samples (Debug)" feature to work for the deferred and path traced renderers in the graph.

Mutable

New:

• Added a new modifier, 'Transform Mesh In Mesh', that uses a secondary mesh as a region to specify a volume in which to transform vertices, using the given transform input.

Rigging

New:

• Improved component editing in skin paint tool

• [Deformer Graph] Added "TwoLayerLinearBlendSkin" deformer function, which serves as an usage example for the new layer skinning option added to the "Skeleton" Data Interface. It allows you to use two skin weight profiles to skin your character. The primary skin weight profile may only contain weights for primary bones like arms and legs, while the second skin weight profile only have to specify weights for tweaker bones (with the exception of the root bone) that are parented to those primary bones.

• Expose TriangleEdit in skeletal mesh editor.

• Improved retargeter debug drawing.

• [Deformer Graph] Added a new version of the "Skeleton" data interface that supports additional features such as

  • Access data from any skin weight profile,

  • Access per-bone animation attributes as bone buffers, similar to the existing bone matrix buffer

  • Enable layered skinning that allows for layering of multiple skinning kernels using multiple skin weight profiles, which may be helpful if you want to separate skin weights for primary bones and tweaker bone into two different skin weight profiles. See new deformer function DG_Function_TwoLayerLinearBlendSkin for example usage.

• Deformer Graph - exposed attribute name as a input property pin on the "SkinnedMeshVertexAttribute" data interface, which can then be driven by a Deformer Graph variable from Blueprint or ControlRig

• A new function, FSkeletalMeshOperations::GetPosedMesh, was added to get a posed copy of a skeletal mesh's FMeshDescription. This function allows specifying either a full set of component space transforms, or a named set of bone space transforms, keyed to specific bones. It also supports activation of morph targets and selecting specific skin profiles to use for posing the mesh.

• Deformer Graph - Added support for a variable node to connect to a constant node to override its value. This may be useful for providing pin default values to input pins on deformer functions/sub-graphs. Users of these functions can override these values using additional variable/constant nodes connected to those input pins. This is a temporary solution before pin default values are implemented for Deformer Graph.

• Deformer Graph - Added a new deformer function "ComputeNormalsTangentsAndKeepImportedNormal" that first computes the rotational offset between the imported normal and the recomputed normals derived from the rest pose vertex positions, and then reapplies this offset to the recomputed normals derived from deformed vertex positions, in a attempt to construct deformed normals that retain the characteristics of imported normals.

• Deformer Graph & Control Rig - Added "AddDeformer" Node in Control Rig, which allows any Control Rig to dynamically add deformation effect to the bound skeletal mesh using a deformer graph during forward solve. Deformer Graphs used in this context can use the new "ReadSkinnedMesh" data interface to read the output vertex buffers from a previous deformer if there are multiple "AddDeformer" nodes present. When right clicking on the "AddDeformer" node, click on "Refresh Variables" to make Deformer Graph variables appear as input pins on the node. See various Deformer Rigs shipped with the "AnimatorKit" plugin for example usage.

• Added "Hammer" weights operation to skin weight tool.

• Deformer Graph - Added a compilation error when there are kernels with no valid execution domain present in the graph

• Deformer Graph - Show "Outdated" on data interface node title if there is a newer version of the data interface.

• Deformer Graph - Added error messages when compiling/running a deformer graph that contains a debug draw data interface with unsupported platform project settings, which should help diagnose why certain deformer graphs are failing silently if it contains this data interface.

• Added ability to Copy/Paste skin weights between selections of vertices.

• Deformer Graph - Added "Skin Weights as Vertex Mask" Data Interface, which combines the skin weights of multiple bones into a single per-vertex weight map. Useful for limiting deformation effects to certain body parts of a character using existing skin weights, instead of having to paint another vertex attribute weight map.

• Deformer Graph - Added support for using Deformer Graph variables/constants to set properties values on data interfaces. See "Skinned Mesh Vertex Attribute", "Skeleton" and "Skin Weights as Vertex Mask" data interfaces for example usage.

• ControlRig - Added a new flag "AllowMultipleInstances" under "Sequencer" category in ControlRigBlueprint class settings that allows multiple instances of the rig to be added to the same character in sequencer. It may be useful for Deformer rigs like the lattice control rig shipped with the "AnimatorKit" plugin, where users can add multiple lattice deformer to the same character.

• Deformer Graph - Added API support for changing the pins shown on a data interface node based on data interface property. See the new UOptimusAdvancedSkeletonDataInterface data interface class for example usage if your custom data interface has such needs.

• Deformer Graph - Added support for array-type variable, which can be driven from ControlRig via "AddDeformer" node by right clicking on the node and click "Refresh Variables", or from Blueprint via "Set Variable" API on a OptimusDeformerInstance, just like normal deformer graph variables.

• When converting a static mesh to a skeletal mesh, using the asset browser, the converter now gives a choice of setting the target path for the skeletal mesh; removing and adding prefixes and suffixes; and allows specifying the root bone location, if not using an existing skeleton.

• Determinism pass on RigVM hashing

• Added isolated selection support to the skin weight editing tool.

• Deformer Graph - Deformer Graph should now also support Mac platform

• Added ability to edit skin weights while previewing the pose from a running PIE session.

Bug Fix:

• Fixes issue in skin paint tool where user could not paint with relax brush unless bone was selected

• Fixe a crash in Control Rig when undocking the hiearchy and closing one editor while multiple editors are open

• Fixes issue where editing skeletal mesh with non-manifold geometry scrambles material assignment.

• Fixed bug where skin weight editor would load non-normalized weights.

• Auto-retargeter window no longer slow in large projects with many animation assets.

• ControlRig - Fixed a dead lock issue that can happen during Control Rig post load, when calling FRigVMTemplate::Resolve.

• Fixes static mesh to skeletal mesh conversion losing multiple UV channels

• Deformer Graph - Fix crash when collapsing a link between a component source pin and a group pin into a sub graph.

• Fixed RigVMEdGraph generating invalid model node paths for EdGraph subgraphs, when a function that contains a collapsed graph is renamed.

• Prevent control rig debug draw displaying in game view mode when high resolution screenshots are taken

• Added some safety checks to compute graph/optimus to prevent crashes on nullptr.

• Fixed an editor shutdown crash due to shared pointer cross dependency at ControlRigModeTools

• Deformer Graph - Fix an out of bound access with Duplicate Vertices Data Interface. It should not use the section vertex index offset because the content of Its data buffers are only meaningful when the kernels are dispatched per material section instead of per mesh.

• Allowed UScriptStructs to be pre-registered for use with FRigVMRegistry

• Deformer Graph Editor - Fix debug draw/shader print provided by the "Debug Draw" data interface not showing up in deformer graph editor viewport

• Deformer Graph - Fixed unconnected "Color" pin on "WriteSkinnedMesh" data interface can lead incorrect/random vertex color values for skeletal meshes using the Deformer Graph.

• Fix issues importing RigVM pin default values for structs with native ImportTextItem implementations

• Switched to using FLazyName for control rig built in types to avoid static init order issues in PGO builds

• Deformer Graph & Skeletal Mesh Editor - Change Skeletal Mesh asset details to show new vertex attribute weight maps under "LODInfo - Vertex Attributes" immediately after weight map layer creation, allowing users to enable new vertex attributes for Deformer Graph usage without having to reopen the skeletal mesh editor.

• Deformer Graph - Fixed Trigger Graph cannot be triggered from blueprint using EnqueueTriggerGraph API

• Deformer Graph - Fixed bad motion vectors when skeletal mesh using a mesh deformer changes LOD

• ControlRig - fixed name related nodes having different behaviors in editor vs in packaged. Nodes like replace/concat now use IgnoreCase.

Deprecated:

• Deformer Graph - Deprecating lattice deformer function shipped with the Deformer Graph plugin. Use the new lattice deformer rigs shipped with the Animator Kit plugin.

Runtime

New:

• Anim notify and sync marker workflow changes

  • Skeletons are no longer dirtied when adding notifies and sync markers from animation timelines.

  • Skeletons can still hold sync markers and notifies, but they are not mandatory and they can all be held in animation assets if required.

  • 'Find References' for notifies and sync markers now launches the find/replace dialog when selected from the animation timeline.

  • Removing notifies and sync markers from the skeleton now does only that. To remove from animations, use the find/replace tab.

• New: Make PhysicsControl work with PrimitiveComponent, not just meshes.

• New: PhysicsControl adds a function that can be used to zero the implied velocities when moving a character.

• Update warning message in UAnimationAsset::ReplaceSkeleton for clarity

• Added Root Motion Attribute handling to Inertialization and DeadBlending nodes.

• ControlRig AnimNode - Added support for using Enums as input pins on the ControlRig AnimNode.

• Disable 'Add Socket' action in skeleton tree when a bone is not selected

• New: Better help text relating to animation syncing.

• New: Adds an editor-only option to enable/disable each BlendSpace sample in "analyse all"

• ModifyCurve anim node now generates debug data

• Updated LLM reporting for Animation Graph to more accurately reflect actual usage.

• Expose functions on the various cached anim state machine types to blueprint

• New: Rename PhysicsControlProfilesAsset to PhysicsControlAsset - no functional changes, and the redirector should fix up any existing assets. Note that this is still an experimental feature.

• [AnimRuntime] Added an optional interpolation override when sampling animations. This makes it possible to force sampling animations in Step interpolation mode even though the Anim Sequence assets are set to Linear.

• New: PhysicsControl supports the body modifier "default" movement type, so it doesn't force a change to the movement.

  • Bug Fix: PhysicsControl/RigidBodyWithControl fixes problems initialising physics assets that have kinematic bodies.

  • Bug Fix: PhysicsControl/RigidBodyWithControl makes sure that when controls are disabled, the constraints are removed and the RigidBodyWithControl reverts node back to its uncontrolled state.

• Added a flag to allow skeletal mesh component's animation to be completely disabled

• Added support for blend mode in Montage Inertialization when used in conjunction with DeadBlending node.

• Added a log at additive retarget bone transform function, to detect bone size differences between the retarget transforms array and the skeleton required bones.

• Add editor option to hide long list of enum blueprint actions in the ABP editor. The bound enum can now me set in the node's property window.

• The RigidBodyWithControl animation node has a viewer (previously called "editor") that lets users see lists of controls, modifiers, sets etc. However, this does not always function as expected, so until it is improved it has been hidden behind the CVar p.RigidBodyWithControl.EnableControlSetViewer which is disabled by default.

• Use UToolMenu for AnimNotifyTrack ContextMenu. This allows users to customize the menu and apply permissions.

• New: Improve help text for BlendSpace evaluator, which doesn't always behave as expected regarding the time input.

• Added option to disable animation ticking when a skeletal mesh is directly occlusion/frustum culled

• Skeletal mesh global scale animation now has a minimum value of zero

• Clamp montage playback when stopping at end of section

• Skeletal mesh editor now uses the required bones to display the skeleton tree, so the bones stays in sync with the preview scene. This will make clear which bones are excluded or not, as the required bones might have some bones that can not be removed from the LOD due to physics or other various needs.

• Improved blueprint navigation speed when several assets are open and we double click to jump to other asset or element, like a state machine state

• Morph target maximum blend wheight is now configurable at render settings. Value can be also controled using a cvar r.MorphTarget.MaxBlendWeight

• New: BlendSpace analysis provides an alternative orientation calculation method which avoids problems when the pointing bone is not restricted to an "upright" orientation

• Added support for mirroring root motion

Bug Fix:

• Fixed a rare crash when running initial pre-evaluate GT anim instance tick

• Fix montages not being marked dirty when (e.g.) adding curve comments or changing curve colors

• Fix issues with selection in the montage editor selection. Marquee selection now requires Alt key.

• Revert changes to AnimGetter nodes that led to invalid data and added a compile time error to check for these broken nodes and instructions to replace them.

• Bug Fix: Makes the action buttons in the BlendSpace details appear when searching

• Fixed crash in blend profiles when skeleton mapping is incomplete.

• Changed 'missing bones' ensure to be a logged error

• Fix notifies not being displayed in context menus under certain circumstances

• Fix for crash when validating auto rule based transitions. Also reinstated some warnings as info

• RandomPlayer anim graph node now calls PreloadRequiredAssets.

• Allowed post process Animation Blueprints to be applied based on a LOD threshold per-component

• Fix budgeted skeletal meshes that are placed in levels not getting registered when playing as client

• Fix for issue where looping level sequences could get stuck on the final frame

• Optimized the opening of notifies/sync marker widget

• Fix edge cases around re-importing meshes with bones inserted into the hierarchy

• Add missing fast path icons for blend space nodes

• Add missing nullptr check on animation blueprint editor preview instance

• Fix to set transient Skeletal Mesh Asset property when value is changed on an actor in level viewport

• Fix viewport cursor style in animation editors when hovering mesh info text

• Fixed issues copying and pasting notify states in montages

• Fixed an issue where the animation notify copy / paste menu items stopped working

• Bug Fix: Ensure the RigidBodyWithControl pose cache is big enough, allowing it to work even when the skeleton is updated whilst the node is operating.

• Fix anim getter node title not updating on state rename.

• Make automatic transition rule account for transit durations smaller than delta time value

• Exposed a native way to get the 'main' anim instance in a thread safe way

• Deprecated USkeletalMeshComponent::SetAnimClass function

• Fix Lyra PIE property access issues caused by use of 'most up to date' classes

• Fix pose watch not drawing correctly for debug skeletons larger than preview.

• Fix copy-pasting shared transition rules not behaving correctly.

• Fixed BlendSpace log spam in TickAssetPlayer function by setting the log as Verbose

• Fix crash in 'call function from anim graph' node BP menu population

• Fix for animation blueprints incorrectly showing animation graphs using animation layers default shared group in my blueprint.

• Removed double-call to RemapTracksToNewSkeleton for 'this' sequence when remapping skeleton

• Fix montage network compatibility between editor and non-editor builds

• Fixed recording of anim notify states in looping montage sections

• Fixed an issue where the experimental AnimNext plugins accidentally showed the beta tag

• Fix bone names being drawn for bones when they're not visible

• Fix crash with setting bone name in skeletal mesh region bone filter.

• Fix an issue where closing a stand-alone viewport resulted in a crash.

• Fix for an issue where WheelController anim node wasn't updating upstream nodes in the anim graph

• Fix FAnimMontageInstance::GetNextSection to return next section of instance rather than the montage default next section.

• Fixed TSAN race condition around bForceRefPose flag

• Fix for aim offset anim node to account for socket offset when calculating pivot location

• Fixed crash when reverting Skeletal Mesh unsaved change while the asset is opened in the editor

• Changed PersonaToolkit raw object pointers to weak object pointers, so validity can be checked

• Account for possible invalid section when montage is force moved

• Fixed OnlyTickMontagesAndRefreshBonesWhenPlayingMontages option updating the anim instance multiple times

• Exposed bShouldStopAllMontages pin in latent Play Montage node

• Fixed anim sequence cooking indeterminism issue with curve names and added some checks to help detect some cases

• Fixed animation budget allocator debug rendering sometimes getting removed

• Fix animation editors selecting the incorrect bone for non-mesh bones leading to array out-of-bounds

• Fixed function renames not applying to property access nodes and compilation crashes post-rename

• URO now ignores non-visible mesh components to prevent invalid LOD params being set

• Fixed problems editing various property types in anim notifies (e.g. FGameplayTagQuery and FRuntimeFloatCurve)

• Fix for cook warning related to skeletal mesh component instance data introduced by 35191113

• Fix issue with byte properties containing enums where default pin values weren't being set

• Fix pose watches not being drawn in PIE

• Fix pose watches using multicolor bones

• Fixed Regenerate LOD button not getting enabled in the Skeletal Mesh Editor under some circumstances

• Fix crash when destroying nodes that have no outer animation blueprint

• Fix crashes when using ref pose overrides when using skeletons with virtual bones

• Fix anim BP node orphan pins not getting removed on disconnection

• Updated icons for animation asset find/replace tab

• Notify list are now refreshed after Undo / Redo on animation sequences, to avoid crashes caused by active tooltips

• Fixed crash setting a preview animation blueprint

• Fix pasted 'anim getter' nodes introducing hidden references to their source animation blueprint

• Fix native bitfield-bool properties writing to incorrect memory when exposed as pins on linked anim graphs

• Fix unfixable warnings when variables referenced in in anim graph node pin bindings are removed

• Fixed a crash at the asset editor module manager due to bad dependency with the preview scene

• Fix animation attribute registration issues with attributes defined as user-defined structs

• Fixed memory leak when switching skeletal meshes and setting animation mode during montages

• Fix for issue where anim streamable couldn't be created directly from anim sequence asset #changelist validated #virtualized

• Breakpoints in Animation Blueprints can now get hit when not debugging a specific object

• Editor fix for transient values being reset at SkeletalMeshComponent for Blueprint created components at PostEditChange

Sequencer

Bug Fix:

• Remove support for weighted blendables in camera animations/shakes. This wasn't really needed, and caused problem with weights animated by gameplay code which would get stomped by Sequencer.

Synthesis

New:

• [MLDeformer] - Enable tests for the editor framework, updated all tests to latest API etc. - Cooking improvements, where stripped data is recovered after cook. - Ability to select a training device. This allows you to pick a specific GPU to train on, or choose CPU. - Added some extra Cuda related logging, to help debugging issues. - Added checks to validate training data, checks for NaN and Inf etc in NMM. - Add another return code from the training, and improve error logging in NMM (show call stack etc). - Some other small typo fixes etc.

• [MLDeformer] Copy over all shared settings when switching between model types.

• [MLDeformer] Removed the delta cutoff threshold property and filtered out bad deltas. This also fixes the problem where the delta cutoff length was removing deltas in post-skinning space in the viewport, while removing them with the same length in pre-skinning space. This would possibly cause deltas removed during training that shouldn't have been removed.

• New: Improvements to the Physics Control Asset Editor. Note that the feature remains experimental.

• [MLDeformer] Changed some default settings to see higher quality result on first training. This makes it easier for new users. More advanced users can tweak the values to reduce memory usage and increase performance at runtime. The values changed are: - Compression level, which was 20 before, but now 1.0 - Delta Zero Threshold, which was 0.0025 before, and now 0.001.

• The File Cache options have been hidden from the UI in the Nearest Neighbor MLDeformer Model with a cvar "MLDeformer.NearestNeighbor.ShowFileCacheCategory". File caching only works in very specific circumstances, and is not recommended except within the same training session, and even still it may not work correctly.

• [MLDeformer] Automatically create two hidden layers when creating a new Nearest Neighbor model. And automatically create a section as well.

• [MLDeformer] Show an error when the deformer can produce visual shading artifacts. This can happen when no deformer graph is used while skin cache is disabled and the materials don't have 'Use with morph targets' enabled.

Bug Fix:

• [MLDeformer] Fixed a bug where the heatmap in ground truth mode would flicker. Playback in ground truth mode is now disabled for now as this causes issues due to differences in geom cache and anim sequence sampling. Scrubbing works as we can force things to be at the right frame.

• [MLDeformer] Fixed a bug where the heatmap could get in a wrong state when toggling it on and off while playing, and while in ground truth mode while playing, and then scrubbing.

• [MLDeformer] Fixed a crash when switching between NMM and NN and back to NMM models.

• [MLDeformer] Fix a crash when saving a level after creating a character blueprint with Vertex Delta Model in it and a compute graph component.

• [MLDeformer] Improved handling of delegate bindings, which could prevent crashes.

• [MLDeformer] Fixed an issue where ground truth heatmaps were incorrect on some frames. Disabled showing ground truth heatmaps while playing the animation as well as that just doesn't work well due to frame differences. Directly added some extra error handling in the Neural Morph Model and logging some info about the Cuda hardware used.

• [MLDeformer] Fixed the timeline from breaking when switching models. This was because some delegates were still pointing to the old editor model which got destroyed after switching models.Directly fixed a few small errors in the comments.

• [MLDeformer] Fixed a crash when having an ML Deformer asset open, with HeatMap enabled, while untrained in testing mode and reloading the skeletal mesh it uses through "Asset Actions -> Reload".

• [MLDeformer] Fixed a bug in the Finalize Morph Targets button where the memory usage wasn't reported correctly. Also fixed an issue where the editor uncooked asset didn't include the compressed morph targets. And fixed a typo in the button's tooltip and added a bit more information. Also made the Finalize Morph Targets button disabled when there is nothing to finalize.

• [MLDeformer] Fixed a crash when there are no input sample animations, and the NMM is set to local mode, and you click a bone.

• [MLDeformer] Fixed a crash when switching models and then clicking the LOD "Auto" button.

• [MLDeformer] Fixed some pytorch deprecation warnings and fixed an issue when switching from global to local mode after having trained in global mode. This had to resample data.

• [MLDeformer] Fixed a crash when packaging a project with a blueprint that has a VertexDeltaModel based ML Deformer inside it.

• Fixed an issue where the Editor may crash on exit after training the Nearest Neighbor Model.

• Fixed an issue where the Nearest Neighbor Model would underestimate the available GPU memory when training, causing it to allocate more than was available.

• Fixed python crashes when training the Nearest Neighbor Model on machines without CUDA.

• [MLDeformer] Fixed a little bug when switching model types. It didn't auto select the correct input anim in the timeline.

• Fixed an upgrade issue when opening existing old Nearest Neighbor Model assets, which would cause some training tools such as the Key Pose Extractor to fail to open.

• [MLDeformer] Fix some crash when pressing Undo in a specific case.

• [MLDeformer] Bug fix when switching back and forth between ML models and then train again. Also some small tweaks to the python training code to move a tensor to the gpu when using gpu. And moved some display logging to verbose while sampling frames.

• [MLDeformer] - Fixed a crash when deleting bones from the bone list in local mode. - Make sure the ML Deformer component gets reinitialized after training and after updating its trained input info object. - Handle the case when the deformer is not compatible with the current skeletal mesh.

• [MLDeformer] Vertex delta model was still using the NNE RDG instead of ORT, which caused it to not be able to run the model properly.

• [MLDeformer] Add an extra improvement to the handling of bindings in the ML Deformer Component. Also removed the quality level from the ML Deformer component as that isn't used anymore since we added LOD.

• [MLDeformer] Fixed a crash in the Nearest Neighbor Model where the GetNumBaseMeshVerts() is 0, which can be caused by the imported model data not to be present.

• [MLDeformer] Fixed a crash and potentially incorrect behavior when switching from Local mode to Global mode in the Neural Morph Model.

DMX

New:

• Conflict monitor now shows a list of objects actively sending DMX even when no conflicts are detected.

• Add progress bars when loading a large DMX library into control console or pixel mapping.

• Control Console - Implement highlight selected patches in the fixture patch list when in custom layout.

• Rework Blueprint Nodes and Runtime API to reset and clear DMX buffers

  • DMX Subsystem now has a Blueprint Node to clear DMX Buffers.

  • Fixture Patch now offers Blueprint Nodes to send default and zero values.

  • Monitors now update when DMX Buffers were cleared.

  • Changing port settings in the DMX Library now clears DMX Buffers.

• Add a compact editor for Control Console that offers a minimal view and can be docked to the level editor.

• The default quality of Pixel Mapping cells is now high instead of low..

• Control Console - Add drag and drop operation in the cue list.

• Add an auto-grouping checkbox for the default layout in Control Console.

• Add shortcut to reload Control Console asset from disk.

• Add a combo box to display and select a cue in the Control Console main and compact views.

• Control Console - Implement ask user to confirm "Store" option when storing a Cue.

• Add physical units and physical value ranges to Fixture Type Functions (editor only). Physical units and ranges export to MVR.

• Control Console - Implement select every similar fader in your custom layout across all fixtures by double-clicking.

• Add "group" and "add" options in the fixture patch list of the Control Console.

• The DMXEditorModule now offers a public method to export DMX Libraries as MVR files.

• Remove the beta version flag from the Control Console plugin.

• The Fixture Type editor no has an option to only display the latest revision of GDTF modes.

• Add controllers exposing editor color property and implementing search bar collapse/expand state in Control Console.

• Add "physical unit" as a value type display option to the Control Console.

• Add renaming Control Console UI options.

Bug Fix:

• Control Console - Fix fader group controller combo box doesn't show the controller name.

• Control Console - Fix prevent double-click from switching from compact/full UI modes.

• Pixel Mapping and Control Console now send DMX values depending on their Stop Mode when their respective editor is closed.

• Fix a bug where the Patch Tool does not show newly created DMX Libraries, fixed a bug where UDMXSubsystem::GetDMXLibraries did not return newly created DMX Libraries.

• Control Console - Fix deleting layout 0 automatically switches back to Auto layout.

• Control Console - Fix Custom Layout Rename button doesn't work.

• Fix Control Console asset dirties on first opening

• Control Console - Fix matrix fixtures can't be removed using the DEL key.

• Fix issues where undo did not work after deleting an Input Source in Pixel Mapping.

• Improve positioning of cells when adding selected patches to pixel mapping, fix cells stop resizing by mouse when either side is 1px.

• Control Console - Fix Fader UI is not updated correctly when switching between custom to auto layout when oscillator class is involved.

• Modes can now be edited in the Details View when multi-selecting Fixture Patches

• Auto-assign now keeps valid stacks of patches instead of aligning them one after another.

• Control Console - Fix various issues related to DMX Editor settings using a custom config instead of EditorPerProjectUserSettings.

• Control Console - Fix user can add all patches or an empty group in custom layout if a filter is set.

• Control Console - Fix faders not updating properly when creating new cues.

• Fix Control Console does not preserve the grid layout when toggling off the Auto-group patches mode.

• Fix Attributes defaulted to the first entry of Attributes in project settings, leading to changed defaults if the first entry changed.

• Control Console - Fix renaming controller causes crash with matrix Fader Groups.

• Control Console - Fix the add patch menu in custom layouts.

• Control Console - Fix engine crashes when the Control Console is upgraded from a legacy Output Console.

• Fixed an issue where OSX did not render DMX Pixel Mappings correctly and sent zero instead of color values.

• Control Console - Fix Control Console UI widgets for controllers.

• Modes can now be selected from the Add Fixture Patch menu as expected.

• Control Console - Fix reset to default option is not performed correctly.

• Fix Compact DMX Control Console window remains open when returning to Control Console.

• Control Console - Fix controllers values automatically synching on grouping.

• Control Console - Fix engine stalls when recalling a cue from a large DMX Library with limited fixture exposure.

• Control Console - Fix matrix controllers don't get ungrouped when auto-grouping.

• Control Console - Fix DMX streaming will stop if DMX library is reloaded.

• Control Console - Fix resetting to Default Values doesn't mark Cue as modified, preventing users from saving changes.

• Control Console - Fix rename muted/unmuted state for Fader Groups/Faders.

• DMXEntityFixtureType::CreateFixtureTypeInDMXLibrary now correctly updates the Channel Span for its DMX Modes.

• Control Console - Fix UI fails to update slider for grouped patches.

• Control Console - Fix add Fader Group/Fader UI buttons.

Deprecated:

• The DMX Screen Component is now fully deprecated in favor of a purely Fixture Patch based workflow.

Editor

New:

• Added the rendered object's name as metadata to the RenderThumbnail CPU trace, in order to quickly diagnose the costliest thumbnail renders

• Move some USD classes and utilities (including access to the USD SDK) to a new USDCore plugin.

• Added support to export CameraRig_Rail animation to USD.

• Groom Bindings are now compiled asynchronously by default in the editor

• Added a setting to control whether warnings logged during validation are promoted to errors

  • FValidateAssetsSettings::bCaptureWarningsDuringValidationAsErrors controls this behavior, and defaults to true to preserve the existing behavior.

  • Note: FDataValidationModule::OnValidateSourcePackageDuringCook now keeps them as warnings, as this is only used by UE::Cook::FDelegates::ValidateSourcePackage and cannot accept a FValidateAssetsSettings argument.

• Group the PreviewPlatforms into submenus organized by PlatformName

• Input of the '-PackageFolder' arg when running ResavePackagesCommandlet is now properly sanitized and the commandlet will warn the user if the provided path did not result in any package files being found.

• Updated SunPosition plugin to add VolumetricCloud component with an updated version of the Hillside clouds material.

• Json Preview Platform for Editor - New menu options for preview platforms to generate/preview devices from json files - Currently only enabled for Android preview platform

• ImageCore::ResizeImage with fast high quality image resizing is now used for Texture Downscale and MaxTextureResolution. More filters added as well as the option to do alpha-weighted resizing.

• Added DoubleClickBehavior to the InteractiveToolsFramework.

• New: Added an additional fallback so we can spawn the Slow Task widget if we are a Program that compiles against the editor, but we don't use the mainframe module.

• New: Skipping Asset Data Updates in the source control module when a actor label is changed if its package is transient. Some tools like the Chaos Visual Debugger need to spawn a large number of transient actors, which will result in actor label creations, which becomes expensive due to that asset data update attempt. Transient packages cannot be saved, therefore we can safely skip the update in the source control module for them.

• Added JsonObjectGraphFunctionLibrary, a set of edit time functions for stringifying objects and persisting those strings to temporary files. Includes two new console commands snapshotblueprints <label> and snapshotblueprintclasses <label> which will write snapshots of all loaded blueprints to a folder as specified by the label. Available to python in unreal.JsonObjectGraphFunctionLibrary, as all blueprint callable functions are.

• Add r.Editor.NeverStartInPreviewMode Disable Preview Platform automatically if Preview crashed

• Add fixer to illegal reference data validation errors

• Added IAssetReferenceFixer (following the pattern used for IAssetReferenceFilter), which allows UAssetValidator_AssetReferenceRestrictions to add a fixer token to any illegal references it finds.

• New config option TextureImportSettings AutoLimitDimension to resize textures at import time to limit texture source sizes.

• TextureAssetActions that modify texture source data can now convert 16 bit per channel source data to 8 bit, eg. TSF G16 to G8. This makes the uasset source content files smaller.

• Removed duplicate Volumetric Cloud assets in SunPosition plugin to use EngineSky assets instead.

• Added UMaterial and UMaterialInstance asset validators to help troubleshoot material compilation issues earlier on. They are disabled by default, see data validation setting "material validation platforms" field.

• Added experimental support to import some USD assets (the same asset types supported by FBX) through Interchange.

• Texture UEDelta filter provides much faster loading of uasset texture files.

• Added option to export skeletal animation as geometry cache to USD.

• Added new OverflowPolicy for text (Middle Ellipsis) can be used also in UMG widgets, there are currently some limitation to it displayed in the ToolTip.

• Batch Renamer release, tool for renaming multiple Assets and Actors at once.

• New: [Plugin Browser] "External" plugins (such as from .uproject AdditionalPluginDirectories, -PLUGIN= command line argument, or UE_ADDITIONAL_PLUGIN_PATHS environment variable) are now displayed in a separate category.

• Added support for new check function for hover capture in Interactive Tools Framework behaviors, similar to the check function for mouse capture in behaviors.

Bug Fix:

• Fix issue where temporary WorldPartition maps generated at cook time could be assigned Primary Asset Ids that would confuse the Asset Manager system

• [Plugin Manager] Target receipt selection now prioritizes editor targets whose Launch executable matches the currently running executable. Previously, the first (arbitrary) editor target receipt with a matching configuration was chosen. This was necessary to disambiguate a second receipt for an editor target in the engine binaries directory, and matches existing logic used to determine the correct receipt in FEngineLoop::AppInit.

• Disable breakpoints during tab restore to prevent editor freeze / infinite loop

• Add PlatformName to FDataDrivenShaderPlatformInfo. In Editor, when using -game we now also load the TPS module of the preview platform if we are using OverrideSP command

• Fix memory leak when the level editor viewport is set to realtime but it's not visible.

• Added support for custom reset to default widgets to IDetailPropertyRow/FDetailWidgetRow

• Allow single property views to hide their reset to default button

• Fixed issue when using Preserve Aspect Ratio on an SWindow where the window would change aspect ratio the first time it was resized if it didn't have an OS border/titlebar

• Re-enable VK SM5 preview for D3D Force SM6 for preview VK SM5, Mac SM5 Enable Lumen Support for Preview VK SM5, Mac SM5 Modifying FeatureLevelSwitch to respect the parent ShaderPlatform FeatureLevel and not the one set by preview in order to have consistent material logic with the Shader Platform we are trying to preview

• Fixed crash when diffing class objects with sparse data

• Fix for crash when adding a component in the level editor after its scene root has been deleted

• Use the Runtime Value of bSupportsInlineRayTracing and bSupportsRayTracingShaders for preview platforms This avoids getting in a bad state where the Preview platform has bSupportsRayTracing=true, but bSupportsRayTracingShaders=bSupportsInlineRayTracing=false while Runtime RHI globals like GRHISupportsRayTracing is true, leading to crashes because of missing shaders. Like Android VK SM5 Preview in D3D Editor

• Bug Fix: Fixed an issue where the OnTabClosed delegate was not triggerd when the Tabs were closed during the Mainframe reinitialization process.

• Fixed material editor crash when trying to restore previously open shader code tab before shader instances are populated.

• Fix property viewer not displaying correctly when setting a UScriptStruct as a container

• Fix some cook nondeterminism bugs involving UWaterBodyMeshComponent and UAtmosphericFogComponent

• Bug Fix: Added a missing null check on FActorTreeItem::OnVisibilityChanged. Some tools like the Chaos Visual Debugger can perform GC on their own, so if a visibility changed event in the outliner is processed while that is happening, we can end up with an invalid actor ptr which will result in a crash

• Fixed crash when diffing assets in inactive plugins

• Always scroll the initially selected item into view for class pickers

• Diffing umap assets now provides a more useful text representation of the map, rather than an empty T3D object

• Fix 100% repro crash on right click for Text Render / Dynamic mesh actors in outliner. Add check class valid AnimationAsset.

• Hide Preview Platform indicator when we hide viewport UI

• Updated clipboard operations in WindowsPlatformApplicationMisc to report an error instead of asserting if clipboard ownership is stolen before CloseClipboard is called

• Make RenderUtils read from TargetPlatformSettings. Fixes the crashes/wrong rendering preview had when the sdk was not installed for the previewed platform

• Added support for importing RootUV attribute from Blender groom Alembic.

• Fixed UEditorValidatorSubsystem::ValidateAssetsWithSettings taking its settings as an out-param rather than an in-param

• Fix a rare crash on editor shutdown caused by incorrect usage of EditorModeManager. Avoid interacting with EditorModeManager singleton during editor shutdown, as it's destroyed in AppPreExit, which is before ShutdownModule is called during editor shutdown (AppExit)

• Fix thumbnails of transparent textures.

• Fixed cases where Color Grading hue, saturation, and value sliders could fail to update when changed in another panel

• Plugin Reference Viewer - Fixed a crash when plugins reference other plugins that have have not been discovered

• Fixed a bug where Asset Guidelines failed to update ini files when the Enable Missing button was clicked.

• Fix ShaderComplexity View crash in ES31 in Editor when SecondayUpscale is active

• Asset Registry tag values are now updated when an asset is moved on disk

• Fix unintended copy of FSelectedActorInfo in MakeTransformDetails Since of the operand in the ternary statement was a temporary object, we held a const reference to a temporary copy rather than a reference to the object pointed by SelectedActorInfoPtr

• Replace Actor will now properly preserve scale and mobility for scene components coming from blueprint classes.

• Fixed Curve Editor Crashes in array remove/clear and undo/redo

• Editor: make viewport FOV computation consistent with the game

Datasmith

New:

• Added the "bExportStaticMeshSourceData" export option when exporting static meshes to USD, which can be used in order to export the source mesh data as opposed to the current render data of the static mesh.

• Added an explicit option to regenerate the LevelSequence that is created for AUsdStageActors when they open a stage. That option can be found on the USD Stage Editor, under the Options menu. In addition, many issues were fixed related to inherited visibilities in USD, and how those map to non-inherited visibilities in Unreal.

• Optimized the opening and import of USD stages that use USD instanceable static meshes.

• Fixed some performance bottlenecks on USD Stage Editor, especially for when opening very large USD stages.

• Implemented support for removing and reloading referenced USD layers and payloads, by selecting the prim with the reference or payload, and right-clicking the target reference or payload on the references panel to the right of it.

• Allow setting USD-related Unreal project settings via Python/Utility Blueprints: Just use unreal.UsdProjectSettings.get_default_object() to retrieve the settings object, and set/get the desired settings via get_editor_property/set_editor_property.

• Exporting skeletal and transform animations to USD will now cover more cases, including components with AnimBlueprints and attach sockets.

• Added an option to the USD LevelSequence exporter called "bExportSeparatePrimsPerSpawnableInstance" to control whether the export should spawn additional prims for each subsection spawnable instance or not

• Implemented a new USD schema to allow explicitly controlling whether prim hierarchies are collapsed or not, when opened or imported in Unreal. Check the schema directly at "Engine\Plugins\Runtime\USDCore\Resources\UsdResources\Win64\plugins\unreal\resources\unreal"

• Implemented a new option called "Use prim kinds for collapsing" (visible on the Options menu of the USD Stage Editor, as a property on the AUsdStageActor and as an import option when importing stages) that controls whether the import process should even use prim kinds for collapsing at all. When disabling this option, prims will not be collapsed by default.

• Added the "USD.LevelSequenceExport.SkipConstantValues" cvar (enabled by default) that controls, for LevelSequence exports to USD, whether we should automatically skip exporting a timeSample value if the previous exported value for that property was identical and the new value is not needed.

• Exporting geometry caches, static and skeletal meshes to USD will now also emit values for the extent attribute

• Allow exporting static meshes with the Nanite override attribute and multiple LODs and at the same time.

• Added support for opening and importing stages with the UsdMediaSpatialAudio schema via USoundWave assets, UAudioComponent and AAmbientSound.

• Implemented support for opening USD stages and authoring new material overrides directly on the generated staticmesh/skeletalmesh/geometrycache components, even if those referenced prims were inside USD instanceables. This is done by the usage of USD collection-based material assignments.

• [SketchUp] Fixed incorrecly exported geometry by baking transform into meshes with SketchUp transform that is not supported by Unreal(like 'shear' or parent scaled non-uniformly with a rotated child component).

• Replaced the usage of Sequencer Dynamic Bindings with Sequencer Universal Object Locators in order to allow creating bindings, on external LevelSequences, to actors and components that are spawned when USD stages are opened via the AUsdStageActor. These bindings automatically repair themselves when the stage is reopened/reloaded.

• The Selection Sync option of the USD Stage Editor is now enabled by default.

• [Solidworks] Added support for Datasmith exporter of Solidworks 2024

• Implemented a new version of the USD Asset Cache (UUsdAssetCache3). This version exposes the cached assets directly on the content browser, which should consume less memory and be more useful, safer to use, and easier to maintain.

• Implement support for muting and reloading USD sublayers by right-clicking on them, on the bottom panel of the USD Stage Editor window.

• Added a new Unreal project setting option called "Log Usd Sdk Errors" that enables or disables the reporting of USD SDK errors onto the Output Log.

• Added a new option on the USD Stage Editor: "File -> Export -> Flattened layer stack", which flattens the opened USD stage's local layer stack into a single layer, but retains reference and payload arcs.

• Add basic support for opening USD stages using UsdLuxShadowAPI (just the shadow:enable attribute for now).

• Renamed 'bReuseIdenticalAssets' to 'bShareAssetsForIdenticalPrims' on the USD import options dialog.

• Improved the USD.DiscardUndoBufferOnStageOpenClose cvar to have it prevent serialization of assets/components after opening, closing and reloading USD stages. This cvar is disabled by default, but can be used in order to gain some performance when opening very large USD stages, in case undo/redoing past the stage opening/closing operation itself is not needed.

• [Solidworks] Metadata export - component, document, generic, summary, custom properties, config properties, comments, BoM table

• Optimized the process of reloading USD stages via the USD Stage Editor (File -> Reload option), especially for very large USD stages.

• Optimized the handling of update notices emitted by the USD SDK when a stage opened via AUsdStageActor is modified.

• [Solidworks] Used PersistentIds for face identifications which fixes issues with face-material connection in the exported data

• [Solidworks] Improved export times

• [Solidworks] Animation is now exported from solidworks using Direct Link Sync

• OpenUSD version was upgraded to v24.05

• Optimized the process of opening and importing USD stages, especially for large stages.

• When exporting LevelSequences to USD, the current level will now also be exported by default, unless another level is provided.

Bug Fix:

• [Solidworks] FIxed exported parts not being updated when changing configs with DirectLink Sync

• Fixed an issue when opening USD stages with non-primitive-shape Gprims within a prim hierarchy would cause the generated, collapsed, static mesh to be invalid and empty.

• Fixed the export of LevelSequences to USD, when the LevelSequence animated blueprints set to rerun their construction scripts continuously in the Sequencer.

• Fixed incorrect transforms when exporting LevelSequences to USD in some scenarios related to attachment tracks, especially if those were on top-level actors.

• Fix ensure being triggered when adding/manipulating animation tracks of unsupported types on the LevelSequence generated by an AUsdStageActor when it opens a USD stage.

• Fix LevelSequence spawnable tracks exported to USD (as visibility timeSamples) never being able to actually hide the objects.

• [SketchUp] Fixed Layer/Tag visibility to take into account Default(Untagged) layer visibility overrides from parents.

• [Datamith exporters] Datasmith exporters correctly inform about plugin upgrade when installing a newer version over the old one

• Fixed how some scenarios would end up generating too many materials when opening or importing USD stages (e.g. if the mesh was doubleSided, the material required different primvars, etc.).

• [Rhino] Fixed failing sync/export when internal texture has no path

• [Rhino] Fixed export of visibility in certain cases, taking parent visibility into account

• Fixed some name collision issues when exporting LevelSequences with spawnable tracks to USD, for those sequences with multiple spawnables that have identical names.

• Fix a race condition when cooking games and applications that use the USD importer plugin using multiple cooker processes.

• [3dsMax] Fixed Arnold light export SkyPortalLight only when the light is a SkyDome in Max

• [3dsMax] Fixed Disk shape type to export as proper area light

• BugFix: [Archicad exporter] Fixed crash exporting Morph elements

• BugFix: [Archicad exporter] Fixed mirrored Morph elements export which caused exported elements to be misplaced before

• [Archicad] Fixel export of Window/Area light orientation

• [SketchUp] Fixed export of geometry normals which causing lighting issues when geometry is transformed within group

• [Solidworks] Fixed mesh actor visibility when exploded view has parts different in different configs

• Fixed many issues related to visibility and visibility tracks, when opening and importing USD stages.

• [Navisworks] Fixex crash exporting high poly density terrain geometry

• Fixed the behavior of AUsdStageActors converted into Spawnables when it comes to loading and unloading the stage, especially when in PIE or being rendered via MovieRenderQueue.

• [CAD] Fixed importing non-manifold geometry hanging the editor

• Fixed a crash when interacting with the LevelSequences generated by the AUsdStageActor after going into and out of PIE, in some scenarios.

Framework

New:

• Engine (map and set add item); Implementing a way to have the map and set fill in with the next available enum value instead of always doing the default value.

  • -- Code --

    • PropertyHandleImpl: FPropertyHandleMap::AddItem() - Added a HasKey() lambda. We're then checking if the map property's key is an enum property, if so, we'll loop the enum values to see if the map doesn't already have that enum value as a key. When we find one that isn't in the map, we're adding a child node and then setting the child's key node to be the enum value that is not in the map yet. If the map property's key is not enum then we do the old check for if the default key isn't there.

    • FPropertyHandleSet::AddItem() - Added a HasElement() lambda. We're then checking if the set property's element is an enum property, if so, we'll loop the enum values to see if the set doesn't already have the enum value as an element. When we find one that isn't in the set, we're adding a child node and then setting the child node to be the enum value that is not in the set yet. If the set property's element is not enum then we do the old check for if the default key isn't there.

    • UnrealTypes: FSetProperty::GetElementProperty() - Added this getter to return the ElementProp property.

• Curve Table Filtering; Improving the curve table uasset filtering so we get more specific matches to the text queries. For example, typing "location" will filter all text with location in it but then typing "location.x" used to filter everything with location and x in it, now it'll filter things with location.x in it. So instead of filtering strings with x in it like "max", it now keeps both of the terms in consideration by finding x and then searching the hierarchy for location as well.

  • -- Code -- CurveTableEditor: FCurveTableEditorItem::PassesFilter() - Updating the string search to not just be a Match() but to find each token in the string's hierarchy.

• Engine (FScriptSetHelper); Adding FindLogicalIndex() to the set helper so we can get the logical index from the internal index. The internal index can have invalid entry indices kept in a continuous list for faster adding after an entry have been removed, while the logical index is all of the valid entry indices.

  • -- Code -- UnrealType: FScriptSetHelper::FindLogicalIndex() - Added this function so we can get the logical index by passing in the internal index.

• Remove CoreMinimal.h includes from plugin template headers

• Adding new cvar to EditorIterationTests named project.iteration.pie.testiterations which specifies the number of times we start/run/stop PIE during the test. Default is 1 to match previous behavior.

• The 'Revision Control Login' dialog will now immediately save settings changes to disk when either 'accept' or 'disable' buttons are selected where as before the changes would only be made permanent when the editor was shutdown.

• Added a data validator that checks for corruption in package files. It will check for truncated files that were not fully saved to disk, invalid package summary info at the front of the package file and that the unstructured data stored in the package trailer is valid.

• AggregateGeom (shape arrays); Adding the metadata specifier TitleProperty so we know what the name of the shapes are in the shape arrays.

  • -- Code -- AggregateGeom: FKAggregateGeom - Added TitleProperty = "Name" to the shape array properties.

• Exports to a .csv file the list of asset references that exist between the plugin and one of it's plugin dependencies

• Utility console command to trace a plugin dependency chain and output the found paths

• Add a RunCommandlet console command. Allows for faster iteration when debugging commandlets in the editor (e.g via hot reload)

• ExportDirectory command added what will export to csv all cross plugin asset references for all plugins found under the specified directory.

• Enabling GauntletModule to support multiple entries/exits from PIE without re-creating its controllers.

• Plugin reference viewer utility suite. Plugin reference graphs can be exported to .csv to detail the number of reference types to each of the plugin dependencies

Bug Fix:

• Updated the Asset Reference Restrictions asset validator to also ignore Verse packages when checking soft dependencies. Previously it only ignored script packages.

• USkinnedMeshComponent (min LOD validation); Adding a validation step to the SetMinLOD(), OverrideMinLOD(), and ComputeMinLOD() function calls so we aren't setting to a value that doesn't have render data. This was seen on lower end platforms where the mesh would be invisible because there was no render data for the min LOD value being set.

  • -- Code -- SkinnedMeshComponent: GetValidMinLOD() - Validate the min LOD value of the mesh component by iterating over render data to make sure we get something usable. SetMinLOD() - Calling GetValidMinLOD(). OverrideMinLOD() - Calling GetValidMinLOD(). ComputeMinLOD() - Calling GetValidMinLOD().

• Fixed an issue where the perforce source control module was not returning the correct workspace root after a user had changed the currently used workspace via the editor ui.

• Fixed a potential shutdown crash in the uncontrolled changelist module.

• Engine (array, map, and set add item); Fixing an issue with the previous TMap and TSet auto increment implementaiton, where if you remove an element in the middle of the array then adding a new entry would incorrectly grab the last index of the container to adjust it. When adding an entry into a container, it will use the first free index (head of the linked list) instead of just adding to the end. Now we'll return the added logical index (meaning, the valid element index and not the internal index) into the container so calling code can get the correct entry if needed. NOTE: There is still a side effect of how we use the first free index of the container, which is really the last removed element of the container. This means that if we then add an element from an enum, it could be in a position that isn't sequential visually. For example, you add all entries with an enum key from 0-5, those keys will match the container index [0] [1] [2] [3] [4] [5]. You remove index 2 and 4 from the container [0] [1] [3] [5]. Now when you add, it'll add the new element to index 4 but the enum would be 2 [0] [1] [3] [2] [5].

  • -- Code --

    • PropertyHandleImpl: FPropertyValueImpl::AddChild() - Added an int32 return type so we can return the logical index of the added child.

    • FPropertyHandleSet::AddItem() - Using the child index from AddChild() instead of grabbing the last element on the container.

    • FPropertyHandleMap::AddItem() - Using the child index from AddChild() instead of grabbing the last element on the container.

• Fixed an issue where attempting to use a workspaces with a root set to a volume root would fail.

• USkinnedMeshComponent (min LOD validation); Removing the log because it can get spammed when render data isn't ready.

  • -- Code -- SkinnedMeshComponent: GetValidMinLOD() - Deleted the logging.

• Fix not being able to edit Gameplay Tag Queries from modal windows

• Fixed crash that occurred when creating an FAdvancedPreviewScene with bDefaultLight set to false

• Fixed ensure when editing CDO properties in FDataLayersBroadcast::OnObjectPostEditChange.

Interchange

New:

• It is now possible to save and load Interchange translator settings via Python and Editor Utility Blueprints (e.g. via the save_settings() and load_settings() functions) in order to "apply" property changes to translator settings.

• Removing PCX importing/exporting.

Bug Fix:

• Deformer settings are now retained when a skeletal mesh is re-imported.

• Fix for FBX exporter not exporting control rig track data when there is no equivalent animation track

Landscape

API Change:

• Deprecated CreateLayerFrom, since it's a duplicate from DuplicateLayerAndMoveBrushes, but missed the brush reassignment, and was unused anyway.

New:

• Removed editor-only data from landscape/water classes in order to avoid issues with missing data in cooked editor. Note that the associated textures have been changed to lazy-load on use (i.e. in the editor only, when the landscape brushes run) so that this doesn't affect the data loaded at runtime

• Adjustments to actionable (landscape) messages UX:

  • Added tooltip when the widget is collapsed to help the user understand what it's about without having to expand it

  • Show the number of affected landscape actors even in the "dirty actors" case to help the user assess how much "out-of-date" the overall landscape is

  • Dirty actors are now handled part of out-of-date landscape proxy flags

  • Optimized update by gathering all out-of-date flags at once (~33% of what it used to cost)

• Various UX improvements for landscape "Select" tool :

  • Don't display target layers, edit layers or BP brushes when using the Select tool, since it makes no sense there

  • Display the Select tool in the Paint panel since it applies there too

  • Refresh the landscape mode details panel when clearing the selection in order to hide the Select tool options immediately

  • Moved the Select tool-specific options into a "Select Mask" category

  • Moved the Select button to the end of the tool list for both Sculpt and Paint panel, since this is not really an editing tool and acts in both modes

• Added system to invalidate VSM pages when using (non-Nanite) landscape, to hide shadow artifacts induced by the vertex morphing system of standard landscape : Relies on pre-computing max height delas from mip-to-mip for every landscape component Invalidation occurs when the evaluated max delta between the heights at the LOD value that was active when VSM was last cached is different enough from the heights at the current LOD value (for a given persistent view), based on a height threshold that is tweakable per landscape and overridable per landscape proxy Invalidation doesn't occur when Nanite landscape is used The invalidation rate is decreased as the LOD value goes up, controlled by a screen size parameter in the landscape actor (overridable per proxy), under which no invalidation will occur. This avoids over-invalidating VSM on higher LOD values, since they tend to occupy less real estate and therefore don't need to have perfect shadows

• Added per landscape (overridable per-proxy) shadow map bias to help with this problem too

• Added 3 non-shipping CVars to help tweak those 3 parameters in-game (landscape.OverrideNonNaniteVirtualShadowMapConstantDepthBiasOverride, landscape.OverrideNonNaniteVirtualShadowMapInvalidationHeightErrorThreshold, landscape.OverrideNonNaniteVirtualShadowMapInvalidationScreenSizeLimit)

  • The whole invalidation system can be enabled/disabled via CVar landscape.AllowNonNaniteVirtualShadowMapInvalidation

  • Added another CVar (landscape.NonNaniteVirtualShadowMapInvalidationLODAttenuationExponent) to tweak the screen-size-dependent invalidation rate curve shape

• Fixed landscape.DumpLODs command : now works without parameter and can be used several times

• Changed CachedSectionLODValues system for landscape to be usable both for ViewState-less views (one-shot renders like water info custom render passes) and "persistent" views (those that have FViewStateInterface associated). This allows to keep track of the previous frame's CachedSectionLODValues for a given persistent view and removes the previous hacky method

• Prevented landscape render systems to have their LOD section values cleared when a render is made on another scene (e.g. any time a thumbnail renders in editor or when custom render passes execute) : now only the render systems that pertain to the scene being rendered get udpated

• Landscape UX fixes

• Fixed some landscape CVars which were not render-thread safe

• Removed redundant calls to SupportsLandscapeEditing when ticking landscape proxies for grass. This is to avoid O(N^2) complexity when iterating on landscape proxies for ticking grass.

• The Resize and Move tools are now disabled instead of hidden when unavailable, and the tooltip mentions why they are not available.

• Optimizations for landscape flatten/smooth tool

• Added info message when there are no target layers in landscape mode, to help the user understand the workflow now requires him to add layers either using the "Add" or the "Populate from materials" button

• Added AllowedDensityRange to landscape Grass Variety. This can be used to prevent a variety from ever spawning on a given range of grass density (specified as an interval between 0 and 1)

• Made landscape collision settings overridable per-proxy

• Added tooltips to Landscape Dirtying Mode settings and made "In Landscape Mode And User Triggered Changes" the default

• Water: Implemented the ability to tag arbitrary actors as "ground" by adding a WaterTerrainComponent. This will cause them to render into the water info texture terrain heightmap and affect wave attenuation, water rendering, etc.

• Improvements to landscape flatten UX:

  • The flatten target value and terrace interval properties are defined in absolute world-space so we now bound their min and max slider values to what that the landscape can actually reach, so that the interval is always valid, regardless of the landscape scale

  • Adjust the preview grid in realtime when the target value is changed via the slider, to make it much easier to eye-ball it

  • Prevent the flatten target value eye dropper tool to validate the change when clicking anywhere outside the viewport or when leaving landscape mode

  • Save the value of preview grid in the user settings

• Landscape mode paint panel :

  • Added filter to target layers list (helps when too many layers are being used)

  • Minor UX improvements

• Landscape: Expose additional rendering properties on Landscape and Grass actors

• Adds SActionableMessageViewportWidget in Viewport's toolbar. This widget will host warnings or messages with the ability to automate actions for the user. Current actionable messages: Invalid Landscape grassmaps, with associated rebuild action Invalid Landscape physical materials, with associated rebuild action Invalid Landscape nanite meshes with associated rebuild action Invalid grassmaps, physical materials, nanite meshes will be agregated to only one message if multiple rebuild are necessary * Landscape proxy packages needs to be updated, with associated mark dirty action

• Added multiple views (split screen) support to SingleLayerWater by using a different slice of WaterInfoTexture and a different water quadtree per view. #changelist validated #virtualized

• Landscape: Make the new layer creation dialog be optional, controlled by the ShowDialogForAutomaticLayerCreation landscape editor setting.

• Disable Retopologize tool button when unsupported (due to edit layers) or when CVar "landscape.EnableRetopologizeTool" is false (default is false).

• Fixed landscape target layers UX refresh issues

• Added info message to explain to the user that all the landscape's target layers are hidden (either by the "Hide unused layers" filter of by the filter text box)

• Used a standard show/hide icon button to the "Hide unused layers" toggle button" in order to help the user understand the status of that filter

• Allowed drag and dropping target layers even when the "Hide unused layers" filter is active

Bug Fix:

• Fixed missing transaction when overriding landscape properties

• Fixed rivers rendering in the water brush : the scene capture component that's used internally was rendering Fog somehow

• Fixed landscape flatten eye dropper tool canceling when clicking on the landscape while keeping the mouse still.

• Fixed editor crash from importing heightmap image files with invalid tile coordinates.

• Fixed crash in landscape alpha brush thumbnails which wrongly assumed that the texture's resource was loaded. Now the thumbnail viewport will keep on being invalidated until it can render the texture

• Fixed crash when resizing landscape

• Drastically reduced severe hang (minutes-> seconds) when clicking on an actor with "Show hidden properties while playing" enabled after a material compiles

• Fixed rare crash when deleting edit layers

• Re-select the affected landscape after using the resize tool in landscape mode

• Moved landscape visibility layer info asset to from EditorLandscapeResources to EngineResources so that it doesn't get stripped on cook when "Exclude editor content when cooking" is used #virtualized

• Prevent landscape target layers from being renamed to a layer name that's already in use

• Fixed crash when landscape fixed grid vertex factory is not created : we would still create mesh batches regardless

• Several fixes with landscape brushes Misc changes :

  • Added landscape.VisualLog.ShowBrushPhysics (0 by default) to avoid polluting the visual logger whenever we move the mouse when landscape sculpting/painting, since that is only relevant to debug the landscape brush

  • Added visual logs when extending the landscape data cache when using the landscape brush + fixed those logs to extend by (-0.5, +0.5) beyond the cached region, in order to properly show the vertices that were sampled (i.e. that allows to show what was cached when the cached region contains a single landscape vertex in either the X or Y direction)

• Fixed landscape Select tool

• Fixed assert when resizing landscape

• Fixed crash when unloading a map while landscape mode is active

• Fixed incorrect ensure triggering when loading old landscape levels that have landscape edit layers textures with more than a single mip. This ensure is only valid if CVar landscape.StripLayerMipsOnLoad is active (it's currently not)

• Don't display landscape on-screen warnings while the landscape is being edited to avoid flickering of the message while stuff get updated in the background

• Fixed landscape material property assignments not being properly undone when using edit layers : in that case, even if the landscape layers update runs properly, if no change was detected on weightmaps, the component material instances wouldn't get updated and the material changes wouldn't get applied

• Fixed Water brush manager not properly reacting to landscape resolution changes

• Fixed landscape.ShowDirty/TrackDirty, which was iterating over vertices without taking into account (subsection) duplicate vertices

• Fix for crash when trying to make a landscape proxy "modified" on PostLoad when the main landscape actor has not registered to its ULandscapeInfo yet

• Prevent user from accidently using a landscape target layer named after the reserved weightmap name for visibility

• Landscape : fixed FBodyInstance being improperly detected as not synced with parent landscape when the content of the collision responses is similar but out-of-order

• Prevented weightmap textures generated by turning edit layers on on a landscape that has it off to have a mip chain, which causes an assert later down the line

• Fix wrong warning when importing landscape weightmap from 8bit source image.

• Fixed rare asserts when using landscape brushes

• Water: fixed GetWaterTimeSeconds so that it can be called outside of the game thread.

• Fix for subtractive blend when using local merge

• Fixed / improved landscape texture diff CVar utilities :

  • One texture / diff report is dumped per landscape paint layer (it used to be one per weightmap, which was incorrect if multiple layers from a given weightmap texture changed, as the last layer would override the other ones

  • Misc minor improvements in the diff report

• Fixed LandscapeInherited properties (from a custom category, like Nanite) that failed to be made disabled and to have their tooltip customized to indicate they are inherited

• Landscape batched merge fixes:

  • Fixed landscape edit layer renderers being renderered in all batches instead of just the ones they intersect with

  • Fixed OOBBox landscape edit layer render item debug display and misc visual logger improvements

• Fixed UWaterBodyComponent::UpdateComponentVisibility updating the water info texture whenever it was called.

• Fixed "Update Water Mesh During Interactive Changes" (Water Editor) setting that has been ineffective for a while now

• Fix crash when building static lighting with a Landscape using WPO by waiting for the async readback to be complete before fetching the results.

• Fix the index that the last row of verts in the collision mesh uses for their color.

Deprecated:

• Removed deprecated code in landscape and water (anything prior to, and including, 5.3)

Scripting

New:

• New: Added Tool Menu Widget for use in Editor Utility Widgets. This widget gives Editor Utility Widgets the ability to create their own menus and toolbars by leveraging the ToolMenus system.

• Expose realtime toggle to level editor subsystem This allows utilities to disable realtime for better performance during intenstive tasks

• Added IsEditorPropertyOverridden to compare a named object property against its archetype value

• Moved FEditorPythonExecuter to PythonScriptPlugin so that it can understand Python directly

  • It will now log an error if the Python script fails execution (to match the commandlet behavior). This error can be made fatal by passing -ScriptErrorsAreFatal on the command line.

  • It will now use a standard async task notification, rather than its own custom UI.

  • It will now defer starting script execution until IPythonScriptPlugin::OnPythonInitialized has run.

• Remove the restriction that Unreal types generated from Python scripts must have globally unique names

  • There are two strategies used internally for achieving this:

    1. If the Python script lives under the project or engine root (and ideally under a content mount point), then a package is created to host any types generated by that Python script.

    2. If the Python script lives outside of any known portable path, then we take its absolute filename (normalized and lowercase) and append it to the generated type name as a hash.

  • These strategies allows a.py and b.py to both define an unreal.uthing() called "Foo" without those two generated types having a conflicting Unreal type name.

  • Note: For backwards compatibility, we leave a redirector from the old-style name to the most recent modular/hashed type name.

• Editor Utility Widget blueprint -Added an option to spawn an Editor Utility Widget as a nomad tab so it can be docked as both major and minor tab.

• Added GetPackageForObject, a function for editor scripts to get the package, principal use is to reload packages

• Exposed AssetViewUtils::GetPackageLengthForCooking to scripting

• This is available via UEditorAssetSubsystem as GetAssetFilenameLengthForCooking or GetLoadedAssetFilenameLengthForCooking

• Added support for modifying spline points within blueprint graphs outside of the construction script via a new 'Set Override Construction Script' method.

Bug Fix:

• Allow Blueprints to add UserDefinedStruct DataTable rows via UDataTableFunctionLibrary::AddDataTableRow

• Don't crash when passing None as the class type to unreal.ObjectIterator

• Instead gracefully handle it and emit a type error: 'type' cannot be 'None'

Deprecated:

• Deprecated creating an instance of a BlueprintFunctionLibrary from Python

  • These types only contain state functions and no state, and so you should just call their classmethods directly on the class from Python

UI

API Change:

• Deprecated SColorGradingWheel, SColorGradingPicker, and related types in the AppFramework and Slate modules. Updated classes with the same names can now be found in the AdvancedWidgets module.

New:

• Revision Control: Add option to copy remote paths

• String UPROPERTY types can now specify a validator UFUNCTION, on the same object, that will validate a user input and show a validation error on the string input, as needed. The function should be static, and takes as input a single FString reference, and returns an FText object. If validation passes, the function should return an empty FText object, otherwise the value of the FText object is displayed as the validation error.

• Make content browser tooltips for 2D and cube texture arrays show array size

• Two utility classes for use with the Details View class FDetailsViewCategoryHiderCustomization - Used to hide entire categories of a Details View. FDetailsViewWarningOrErrorCustomization - Used to insert an SWarningOrErrorBox into a Details View at the top of a specified category.

• Kismet: Added slate argument to SKismetInspector to specify if the section selector should be shown.

• [PropertyEditor] Moved CallInEditor functionality to shared location. You can now replictate this functionality, previously hard coded within ObjectDetails.

  • See FObjectDetails::AddCallInEditorMethods for usage.

• Added SActionButton to the ToolWidgets module, and exposed the icon color. This is a less specialized version of SPositive/NegativeActionButton that doesn't imply intent.

• Tweaked formatting of project badge in editor to avoid unnecessary spaces

• New: Added the experimental ImageWidgets plugin containing generic Slate widgets for displaying and interacting with images and image-like content. The currently provided widgets are SImageViewport for displaying and interacting with images and image-like content, and SImageCatalog for listing and interacting with a set of images.

• The texture editor now shows relevant information, warnings, or errors for the current texture in the texture viewport.

• The editor can now decode and view textures encoded for other platforms - notably, ASTC encoded textures for mobile platforms can be viewed in editor for quality reference.

• Added tooltip with help text to console suggestions

• ToolMenus: Added reusable UToolMenuWidgetCollectionContext class. Allows adding/finding widgets in a generic way, which should reduce the need to create custom context classes.

• Added Select All/None button for column view right click context menu in the Content Browser

• Folders can now be added to Favorites by simply dragging them in.

• Changed color grading wheels to a clean, modern style that scales nicely to large monitor sizes.

• Added supports for profiles for the ContentBrowser.AssetViewOptions menu The activated profile can be specified using the FAssetPickerConfig struct

• Added new default animation editor preview profiles for editing purposes with grey background and nicer wireframe rendering.

• Reorganized the Details panel for Color Correct Regions and Color Correct Windows for more convenient access to important properties.

• Add an EditorPerProjectUserSettings override for Texture import PNG infill setting. This is so UI artists can set that to "always" for UI work without affecting other users.

• Added customization support to properties added as external objects at propertyy editor

• Revamped the place actors panel UI and added a Favorites category.

Bug Fix:

• Fixed a problem with tooltip force fields, where if the force field would push the tooltip towards an invalid position (e.g. when forced down but the tooltip ends up outside the screen), the force field would end up being ineffective. With the fix, we're still trying to push the tooltip in the best direction, but if that fails, we're trying the other direction

• Fixed crash when reloading texture being used as an atlas while it's sprite is visible

• Fix VolumeTexturePreview using incorrect SizeZ calculation

• The config-file value "ProjectBadgeBackgroundColor" is now respected again.

• Fix for ThumbnailManager singleton shutdown crash, due to the thumbnail pool trying to access the singleton in the destructor

• Account for LOD bias when determining volume depth slice count in texture editor

• Fix 1-frame glitch in texture editor when changing mip level

• Fixed issues with Nanite object highlights and selection outlines while editing a packed level actor in the Level Editor.

• Fixed an issue that could cause the text alignment on an SPrimaryButton to be incorrect.

• Fixed panning of the texture atlas visualizer

• Fixed a rare crash when interacting with an Asset Editor with the Viewport tab closed.

• Fix an issue where the level editor "Favorite Levels" main menu would be hidden if there are no recent levels.

• Fixed issue where the PIE window would grow over time when launching PIE in a new editor window

UX

API Change:

• New API is disabled by default, to enable set CVAR Editor.EnableITFCursorOverrideSupport > 1

New:

• Added Lit Wireframe viewmode, which combines MeshEdges with the Lit viewmode

• Added categories for custom notify class properties in the details panel. All properties on the notify class will now show in their appropriate categories in the detail panel when selecting an animation notify in the animation editor. The categories will be placed as subgroups of the "Anim Notify" group. Any properties without a category will be placed directly under the "Anim Notify" group. Properties that explicitly specify a category of "AnimNotify" will be added to the "Anim Notify" category directly as if they did not have the "AnimNotify" prefix to prevent showing an extra nested category.

• Added new options for loading presets in the Console Variables Editor, allowing you to either replace or add to the existing settings.

• The Play-in-Editor toolbar now shows a Simulate button front and center. It's now easier than ever to jump straight into a Simulation without first playing or navigating a menu.

• Added button to open selected data registry asset for FDataRegistryType detail customization

• Added the Color Grading window, which provides a convenient interface for creating and controlling color grading objects, and which scales nicely on large monitors.

• Added console command tooltips when displaying the history Also, for the console command text box, there is now a tooltip for the command currently being typed (if it's valid), which also displays the current value for CVars (to avoid typing the variable without parameter, switch to the log window to peak at the current value and back to the console command to enter a new value) Also added tooltips forcefields for both the edit text box and the suggestion list view

• Polished the Console Variables Editor's interface, bringing it in line with Unreal Engine 5 style.

• Added the ability to disable or delete multiple selected items in the Console Variables Editor.

• Added right-click menu option to open underlying asset (data table, curve table) from data registry editor. Made right-click on data registry row highlight the row.

• Provide new API for controlling mouse cursor styling during tool operations and prevent excessive hit proxy testing when the Interactive Tools Context has mouse capture active.

• Changed RebuildModeToolBar and ShouldShowModeToolbar methods to be virtual, allowing derived toolkits more flexibility over constructing and managing the mode toolbar.

Bug Fix:

• Fix an issue where menu search fields didn't respect the "Menu Search Field Visibility Threshold" setting.

• Improved editor performance when moving Light Cards using the Unreal Stage app.

• Fix a bug where the hotkey for "Open Level" (Ctrl+O on Windows and Cmd+O on Mac) didn't work after clicking on a tab.

• Use cached transforms for Pilot transactions to allow for other transactions to occur while piloting.

• Fixed Place Actor menu for Custom Actors (e.g. Runtime Virtual Texture Volume)

Foundation

New:

• Add EAutomatinTestFlags::ProgramContext flag to filter tests for Program target.

• Add StaticLoadAsset, LoadAssetAsync, and FSoftObjectPath::LoadAsync functions to make it easier to asynchronously load objects from C++. Also improve the comments to note which loading options are actually deprecated

• StudioTelemetry's log analytics is now disabled by default.

• Optional property support for StructSerializer & StructDeserializer.

Bug Fix:

• Maps that use redirectors for sublevels can sometimes hang the editor. (Partial fix) In rare cases, moving maps with streaming levels could end up serializing PackageNameToLoad. This could happen if a map was moved and the asset registry hadn't updated its soft path redirect table before ULevelStreaming::Serialize was called. As a result, PackageNameToLoad would be saved to disk with the updated path. However, if the map were moved again, there would be a discrepancy between PackageNameToLoad and WorldAsset. This would eventually create a corrupt UPackage where the name and file path don't match. Eventually, the editor would hang as it failed to load the streaming level and repeatedly re-attempt. For now, we'll just clear out PackageNameToLoad during these scenarios. At some point, we'll need to phase out PackageNameToLoad completely in favor of WorldAsset. Having two fields attempt represent a package path is a bit clumsy and error prone.

• CborStructSerialalizerBackend fixes for FSoftClassProperty. Serialize it like FSoftObjectProperty, where the path can be valid even if the object reference isn't.

• Fixed an issue where Studio Telemetry could cause extreme performance issues in the editor when run on certain hardware configurations

Build

New:

• Intel® Implicit SPMD Program Compiler has been updated to version 1.24.0.

• Added DeprecatedEngineVersion to plugin descriptor to be able to warn when a plugin is deprecated and will be removed in future engine versions.

• Calling the CustomCopyHandler during CreatePakResponseFileFromStagingManifest

• Adding support to the BuildGraph system to allow properties first declared inside a macro to be flagged as CreateInParentScope causing them to be created in the scope containing the macro invocation. This allows macros to be used to define collections of properties. This pattern is now used in EditorPerf.xml inside the SetupPerfProject macro.

Bug Fix:

• Fixed FastBuild failing to distribute .hlsli files.

• Nastepfilters re-added back into Visual Studio project file generation.

• Fix data race in UBT DataDrivenPlatformInfoIniIsPresent

• Adding UE_DEPRECATED_FORGAME and UE_DEPRECATED_FORENGINE to known optional tokens parsable by UHT. E.g. usable for enum entries.

• ModifyConfig action in buildgraph is not preserving quotations on original value.

• SN-DBS: Fixed the problem of distributed builds leaving ghost jobs running in the background after failing a build under certain conditions.

• Fix an issue with making chunked builds due to incorrect quoting of path

• bEnableNoInlinedWarnings=true causes crash under specific module fileset

• SN-DBS: Fixed possible issues with distributed builds not handling the cl-filter tool correctly.

• SN-DBS: Fixed incorrectly set timeout which could lead to spurious fails of long running jobs in distributed builds e.g. when building shaders on some platforms.

Core

API Change:

• Change storage container from TSet to TArray for passing into UAssetManager::GetPrimaryAssetLoadList, ensure no duplicate assets were added to that list later on a higher level or use TArray::AddUnique().

• As part of the fix to TSoftObjectPtr's API, some expressions may now fail to compile, like comparing TSoftObjectPtr with a TObjectPtr. This should be fixed by disambiguating the conversion by calling .Get() on the TObjectPtr to convert it to a UObject*.

New:

• The 32 byte FIoChunkHash used by UnrealPak and iostore has been deprecated and replaced with the 20 byte FIoHash, and at the same time the command line argument -verifyhashdatabase was renamed to -validatechunkhashes and the IIoStoreWriterHashDatabase interface was removed.

• UTexture::ForceRebuildPlatformData will now build Final when passed an encode speed of FinalIfAvailable, rather than always falling back to Fast. This fixes an issue where failed fetches for FinalIfAvailable would enqueue deferred force rebuilds of textures that will be rebuilt as Fast encoding. Subsequent runs of the editor will still miss on the same texture using Final encoding, and again kick off a rebuild for the already built Fast texture never populating the cache with Final texture data through normal editor usage.

• Added UE_REQUIRES_FRIEND and UE_REQUIRES_DEFINITION to allow forward declarations and friend declarations with constraints.

• [TextKey] Make TextKey SlabSize configurable with UE_TEXTKEY_SLAB_ALLOCATOR_SLAB_SIZE and bump the default size to 32k (64kb when using widechar). In tests this has saved up to 20Mb of memory. [RN] TextKey SlabSize is now configurable with UE_TEXTKEY_SLAB_ALLOCATOR_SLAB_SIZE

• Added FMath::FloorLog2NonZero to enable optimizing callers where the value is known to be non-zero

• Added support for TUniquePtr<void> and restored support for TSharedPtr<void>.

• Changes the zenloader interpretation of the flag RF_WasLoaded to match the -nozenloader meaning by setting the RF_WasLoaded flag on the linker root object once the package load is complete. Before zenloader would set this flag during creation of the package but before any loading had occurred. Any code guarding access to an partially loaded object will now be correct if guarding against objects missing RF_WasLoaded. However this change does means code looking for partially loaded objects will now need to look for RF_WillBeLoaded specifically.

• Added detection and reporting of Cancel() and Wait() deadlocks in the DDC FRequestOwner

• Added Algo::Mismatch.

• Changed mip streaming to use query DDC with GetValue rather than GetChunks so that data fetching can propagate between the caching layers. Previously if data didn't exist locally, but did remotely, we would consistently miss every time locally, and have to pull data from the remote. This removes thousands of cache misses that can happen every time you load the editor with a local cache less populated than the remote cache.

• Moved Color Management logic & classes into the Core module.

• Fix const range-based for loops over TBitArray<>

• Added TArrayView support to TSet's constructor, fixed TArrayView deduction in its Append overload, and added CTAD support for constructing TSet from a range.

• UObject::Rename will no longer call ResetLoaders implicitly as this frequently would break recursive loads by resetting the loader while still in use. Instead, ResetLoaders will be called when UObject::Rename would be moving an object to a new package with a different loader since using the loader after renaming would very likely be unintended and result in errors. If you do want a mismatched loader after renaming, provide the REN_AllowPackageLinkerMismatch flag when renaming.

• DDC - Added ability to override OAuthIdentifier for Cloud DDC layer with env variables or command line arguments

• Reduce the sleeping done in AsyncCompilationHelper::FinishCompilation and corrected all engine implementations of ICompilable to properly signal their completion rather than internally polling and sleeping dragging out slow tasks completion times.

• FTopLevelAssetPath: Add support for appending to FUtf8StringBuilderBase. Add support for writing FTopLevelAssetPath to FCbWriter. Add support for loading a FTopLevelAssetPath from FCbFieldView. These changes allow FTopLevelAssetPath to be output via structured log.

• Added TDelegateRegistration and TMulticastDelegateRegistration classes, which can be returned from OnX() functions to allow users to bind or unbind from owned delegates but not invoke them, a bit like C# events.

• Added FObjectPropertyBase::SetObjectPropertyValueUnchecked variants of the existing functions which don't guard against invalid operations, like setting nullptr to a non-nullable property.

• Added FindLastFrom to TBitArray

• Improvements to TIntVector2, TIntVector3 and TIntVector4 to bring them closer to parity with the functionality available in the corresponding TVector classes.

• Added TSharedFromThis::AsSharedSubobject(&Subobject) and TSharedFromThis::AsWeakSubobject(&Subobject) to allow easy access to the aliasing constructor.

• Add TArray/TArrayView/FStringView::NumBytes() and FString::NumBytesWith[out]Null()

• [Rider] Expose additional project properties from UBT to Rider

• Made TVariant trivially destructible if all the types are trivially destructible.

• [Rider] Fixed missing system include paths on macOS

• Added FMath::WrapExclusive which gives more expected results for integral types. Deprecated FMath::Wrap for integers.

• Add a thread-safe ref-counting mechanism to UObjects. Make TStrongObjectPtr more light-weight and usable on any thread by using ref-count instead of FGCObject. Add a pinning API to WeakObjectPtr so they can be converted safely to StrongObjectPtr from any thread. Make delegate broadcast thread-safe when used with UObjects by pinning during broadcast for non game-thread.

• Added tracking and storage of unknown enum names and impersonation of enum types

• TMulticastScriptDelegate archive stream operator is now slightly more conservative about what types of access rights are required based on the type of archive being processed. An archive marked IsSaving will now only require read access. Made a corresponding change in FArchiveGatherExternalActorRefs to ensure that it reports as IsSaving and thus only needs read access. This enables use during concurrent save.

• The old task graph API now uses the new task system under the hood to improve scheduling behavior.

• Added intrusive unset optional states to TSharedPtr and TWeakPtr.

• FConfigFile can now be put in a mode where it will parse the ini file as python configparser does.

• Added UEnum::IsValidEnumValueOrBitfield() for checking if an enum value allows a combination of flags.

• Provide better API for AssetManager and StreamableManager to allow additional performance optimizations. Let the user pass TArray instead of the TSet into GetPrimaryAssetLoadList which let them avoid creating of unnecessary array copy when passing the list to AsyncLoading.

• Add support for compressed binary PackageStoreRequest

• Add PlatformMemory::KernelAddressBit to enable an extra high-bit for pointer tagging

• Option to disable anaylzing engine modules or generated code

• [PVS-Studio] Added a new format of the analyzer report

• Added multithreaded data processing support for Asset Registry. In case of problems, this can be disabled with -dpcvars=AssetRegistry.TickGatherOnGTOnly=1

• Changes the trace marker used for denoting GameThread async flushes to now clarify if a flush of all in-flight async loads is being performed or if the game thread is flushing only a subset of all loads. The "Flush All Async Loads GT" marker makes it easier to detect and fix bad behaviour since, except for a few special cases, we should never wait for all loads and instead should be specifying a subset.

• Added cvar CoreUObject.NonNullableBehavior to control if non-nullable properties produce an error, a warning or a default object when failing to resolve an object reference. Default objects will not be created if the class is abstract.

• Made UE_STATIC_ASSERT_COMPLETE_TYPE take an optional message, like regular static_assert does.

• Defaulted - via T() = default; - many class constructors that also have a EForceInit constructor so that value-init works and we get better compiler warnings when they're uninitialized. Includes TBox2, TBoxSphereBounds, FLinearColor, FColor, FInterpCurvePoint, TMatrix, TPlane, TQuat, TRotator, TVector2, FVector_NetQuantize, FVector_NetQuantize10 and FVector_NetQuantizeNormal.

• Added a UE_DEFINE_PRIVATE_MEMBER_PTR macro that allows access to private members of classes without explicit permission (friendship) from the class.

• Replaced persistent auxilary memory with a new Persistent Linear Allocator. Some persistent UObject allocations were moved to it to save memory

• Added CSV scope markers for ResetAsyncTraceTickTime and WorldPreActorTick to reduce the amount of unknown time going into WorldTickMisc [RN] Added CSV profiling markers for ResetAsyncTrace and WorldPreActorTick

• Added UEnum::GetValueOrBitfieldFromString() for parsing a bar-separated string (but not bar-separated integers) into a flag-based UEnum. Added UEnum::GetValueOrBitfieldAsAuthoredNameString() and UEnum::GetValueOrBitfieldAsDisplayNameText() to match UEnum::GetValueOrBitfieldAsString(), for authored names and display names respectively. Added support for serialising enum flags and converting to/from text.

• String: Added string case conversion functions under UE::String.

• Update minimum MSVC to 14.38.33130 & minimum Visual Studio 2022 to 17.8

• FCoreRedirects is now thread safe.

• Improve performance of inserting elements into the asset preload list if the uniqueness is guaranteed by the caller.

• Added MakeConstArrayView.

• Expose GC time interval parameters inside UEngine. Allow override GC frame budget.

• IncrementalCook: Add UE::Cook::IDeterminismHelper to write diagnostics for cook indeterminism and false positive iterative skips.

• Added multi-process support to the saving of derived data cache replays

• AssetRegistry: Turn on async scan and use of cache in editor -game and editor -server modes; the AssetRegistry is used in all game modes during startup and needs to be cached in all game modes. Delete all code for the non-monolithic cache; the monolithic cache now handles all cases.

• Introduced _CONDITIONAL variants to TRACE_CPUPROFILER and UE_TRACE macros.

• • Added FAutoConsoleVariableDeprecated (and FAutoConsoleVariableShadow), which can be used to change the name of a cvar but leave a shadow cvar behind with the old name, so old ini files are not broken, and can control if the user gets warnings, asserts, etc when used - Added support for skipping over Shadow cvars when all CVars are iterated over programmatically, so they are only used directly (like when one is in a .ini file)

  /ul>

• Changed UWorld::BlockTillLevelStreamingCompleted implementation to no longer flush all in-flight async loads globally and instead only flush outstanding streaming level async requests. In large projects this can save significant amounts of time entering PIE. Specifically,

  • ULevelStreaming now provides a protected member AsyncRequestIDs to keep track of async loads issues when loading a level. During OnLoadingFinished AsyncRequestIDs will be cleared.

  • If a child class of ULevelStreaming has not recorded any async loads in AsyncRequestIDs, we fallback to flushing all async loads as before since we can't know if implementers are relying on the past behaviour of a forced flush of all async loads.

  • CVar s.World.ForceFlushAllAsyncLoadsDuringLevelStreaming has been added allowing one to revert back to old flushing behaviour temporarily while work to track necessary loads can be done.

• Replace busy wait APIs with oversubscription to fix common deadlocks and reduce CPU usage.

• r.ShaderCompiler.JobCacheDDCEnableRemotePolicy is set to true by default now. Individual shader jobs will be cached to remote/shared DDC instances in all operation modes rather than only to the local machine.

• Added UE_REQUIRES_EXPR for wrapping up C++20 requires expressions.

• Eliminated most blocking during requests in the DDC ZenCacheStore

• Add a new commandlet '-run="VirtualizationEditor.GenerateMountPointPayloadManifestCommandlet"' that generates a report on editor bulkdata payload usage grouped by mountpoint.

• Fix commas in unit test expressions in LowLevelTestAdapter for FAutomationTestFramework

• Added UE_DEPRECATED_HEADER which acts like UE_DEPRECATED and should be placed in headers that should no longer be included.

• Added [[nodiscard]] to more of the Compact Binary API

• Added UHT support for FAnsiString and FUtf8String.

• UnrealMathSSE cleanups enabled by having SSE4.2 min spec; also some UnrealMathNEON cleanups.

• Add support for studio telemetry. Requires connection info to be defined in a BaseEngine.ini config, as well as opting into those providers via a BuildConfiguration.xml setting

• Added moves to RelocateConstructItems.

• MPCook And CookPackageSplitter: Allow each splitter class to opt out of the new behavor allowing generated packages to be retracted. Some splitters need to run BeginCacheForCookedPlatformData before they can decide which packages to generate.

• Improved performance of FMallocBinned2 and FMallocBinned3

• Eliminated most blocking during get requests in the DDC HttpCacheStore

• Moved the reference-counted TSharedString from DDC into Core

• Improving asset leak reporting when unloading plugins by ignoring the effects of the RF_Standalone flag.

• Added a check to MakeShareable to ensure that you're not trying to call it on an already-shared TSharedFromThis object, as this will result in a double delete.

• The existing UnrealPak feature -compressionEnableDDC for iostore compression has been optimized by implementing the newer DDC2 and Tasks APIs. It makes up to 128 inflight get requests and 128 inflight put requests up to a memory limit of roughly 2 GiB and uses batches of up to 8 items with a soft 16 MiB cutoff limit. Shaders, umaps and io chunks smaller than PackageCompressionMinBytesSaved or PackageCompressionMinSizeToConsiderDDC are currently excluded from DDC to reduce the cache churn.

• Added a DDC FCacheKeyBuilder to support creation of cache keys

• [Rider] Fixed missing toolchain include paths on Linux

• Fix -execcmd parsing to allow multiple instances

• De-inlined complex MemoryOps functions and coerced TFunction and TUniqueFunction bindings into function pointers if possible, to reduce the number of template instantiations.

• Added InitFromString function to FIntPoint / FIntVector to mirror their ToString function * Added unit tests for InitFromString for FColor, FLinearColor, FVector, FVector2D, FVector4, FQuat, FRotator

• Added intrusive unset states to various containers. Modified TOptional's move/copy constructors to avoid moving/copying an element type in an intrusive unset optional state, in case the element type doesn't or can't support them.

• IterativeCooker: ConfigAccessTracking: Replace the limited tracking present in AccessDetection::ConfigIni with a more detailed version that calls arbitrary callbacks on each ConfigValue read.

• Added UE_DEPRECATED_FORENGINE deprecation warnings for engine modules.

• UPackage::SavedHash: Add the API that replaces UPackage->Guid. FIoHash SavedHash (or PackageSavedHash ) is now used instead on UPackage, FPackageSummary, and FAssetPackageData. UPackage->Guid is now deprecated; we will remove it in 5.5. This replacement only applies to the editor; in the cooked game we are removing UPackage->Guid with no replacment because it is unnecessary and costs memory.

• Added a -setby= option to DumpCVars, to filter on how they were set, like "DumpCVars r. -setby=DeviceProfile" will show all rendering (r. prefix) that were last set by a DeviceProfile #changelist validated #virtualized

• Added .natvis for TraceServices::TPagedArray.

• Optimized memory footprint of FMallocBinned2 and FMallocBinned3

• Disable Studio Telemetry in Shipping builds

• Add cvars VeryLargePageAllocator.MaxCommittedPageCountDefault and VeryLargePageAllocator.MaxCommittedPageCountSmallPool to limit the number of large pages committed for each pool. Since VLPA very rarely releases pages, this avoids the situation where VLPA permanently holds too much memory, leaving less for other large allocations or rendering etc.

• Added DispatchDynamicLogRecord for advanced log dispatching use cases

• Added a TString<CharType> alias to map a char type to its corresponding string container type.

• FConfigBranch - Big refactor of how FConfigCachelni and FConfigFiles are read in, stored, and modified at runtime

  • FConfigBranch maintains the data of the hierarchy of layers (ie files) that make up the final resulting config values that are queried at runtime (editor keeps full data, non-editor defaults to collapsing all static config layers, for memory reasons)

  • Adding dynamic layers (plugins, hotfix, etc) is now a reversible operation, by having the state of the layers still around

  • When a dynamic layer is removed or added, in-memory changes are remembered (via a diff operation), the list of layers is updated, the combining logic for dynamic layers is run again, and the in-memory diff is patched back on top, then callbacks are fired to update cars, device profiles, object properties, etc

  Additional memory saving functionality has also been introduced:

  • SafeUnloadBranch - you can unload a branch from memory, and with the known hierarchy in the branch, any access to that branch will cause the system to quickly reload the data into memory. It can be a small hitch, but if you know you likely don't need a branch again, it can be safely unloaded

  • Optionally, SafeUnloadBranch can be called after N seconds have passed with the branch not being read from.

  • This is car controlled, and is recommended only for very low memory situations

• UnrealBuildTool: Intel ICX 2024.2 integration

• Setting to control print level of PVS-Studio analyzer warnings (-StaticAnalyzerPVSPrintLevel)

• Decoupled StudioTelemetryEditor from StudioTelemetry and moved it into its own Plugin EditorTelemetry This makes StudioTelemetry lighter weight and no longer dependant on the Engine and Editor leaving more useful for applying to other systems or applications outside of the Editor or Client Added OnStartSession, OnEndSession and OnRecordEvent delegates that are used by EditorTelemetry to Start/Stop its own session at the time StudioTelemetry starts and stops.

• [RN] Encapsulated the property data argument of PropertyVisitor callbacks to an object that also includes the parent struct data.

• Added an API to FRedirectCollector to provide read access to the global list of discovered asset redirects.

• Added new UE_ preprocessor metaprogramming macros to replace the PREPROCESSOR_ macros to aid readability and discoverability: UE_STRINGIZE, UE_JOIN, UE_JOIN_FIRST, UE_IF, UE_COMMA_SEPARATED, UE_VA_ARG_COUNT, UE_APPEND_VA_ARG_COUNT, UE_EMPTY, UE_EMPTY_FUNCTION, UE_REMOVE_OPTIONAL_PARENS

• [PVS-Studio] Add new PVS-Studio.exe silent exit code mode.

• Accelerated CreateLinkerExports during loading in Editor by dramatically reducing memory traffic for assets with many exports. When loading a real-world UMap with 2M exports, we now take 25 seconds compared to 44 minutes.

• Moved UserDefinedStruct to CoreUObject

• Added RemoveAt*(Index, AllowShrinking) overloads to FString, FAnsiString, FUtf8String, TObservableArray, TIndirectArray and FPreviewAssetAttachContainer to match TArray.

• Support adding additional debug visualizer files to be linked when a module is referenced with ModuleRules.PublicDebugVisualizerPaths

• Add overload of IPlatformFile::OpenRead that can return error messages and takes it's parameters in the form of a bitfield enum.

• Added missing GetLongPackageFName functions to SoftObjectPtr variations. The underlying FSoftObjectPath has a GetLongPackageFName, which is sometimes useful to call via the owning soft pointer.

• Added an option for users to premit/restrict sending of User data and Hardware data. Adedd ability to turn off Telemetry capture altogether. Telemetry is ON by default User data is OFF by default Hardware data is ON by default Added commandline options for user to control what is sent by Telemetry: ST_SendTelemetry=true ST_SendUserData=false ST_SendHardwareData=true

• Added optimized single element TArray Remove* overloads which don't take a count.

• Introduced a new type of FCoreRedirect, Type_Asset. This can be used to implement behavior in cooked builds similar to what is provided by UObjectRedirector in uncooked builds.

• Added FValueId::MakeIndexed to the DDC API to more easily support arrays of values

• Added FPaths::IsStaged() which can be used to determine if you are running while staged. Since staging can remap directory structures, it can be important to know if staged (especially for staged programs)

• Upgrade bundled dotnet to 8.0.300

• Added UE_LIFETIMEBOUND attributes to TArray functions which return element references. Added MSVC support to UE_LIFETIMEBOUND.

• Added TSet::FindArbitraryElement, TMap::FindArbitraryElement and TSortedMap::FindArbitraryElement.

• Improves DoesPackageExistEx by enabling it to use the AssetRegistry when available, avoiding costly OS calls.

• Added explicit configuration of the DDC file system cache as local or remote, with a fallback on Windows to detect a remote cache automatically

• Added a custom import function to JsonObjectConverter methods to match the existing custom export callback.

• Support for joining tuples, using a new set of UE::Strings::JoinTuple* functions.

• Added -DDC-ForceMemoryCache to allow the editor to boot when the cache is misconfigured

• UStruct::IsChildOf<T>: Support classes which provide StaticStruct, in addition to those which provide StaticClass.

• Allow projects to opt out reporting loaded plugins in crash reports. This helps reduce the size of crash reports for project with many plugins.

• UnrealBuildTool: Handle Ctrl-C to gracefully cancel running action queues

• Added FUtf8StrProperty and FAnsiStrProperty.

• PerPlatformProperties can now be declared for data types outside of Engine, for example enums declared in game or plugin code.

Bug Fix:

• Fixed many placement new calls in many Core containers to ensure that they still work with types which haven't overloaded operator new.

• Fixed moving arrays of const TArray elements into array of non-const TArray elements (a const-incorrect operation).

• Fixing static analysis warning related to auto& on a TCHAR constant.

• Correctly add project source dir to include path when building a generic target (UnrealEditor, UnrealGame) with a -Project

• Fixed TOptional::Emplace constructing over an already-constructed inner object when it's in the intrusive unset state.

• Add list of subrules files to generated Rider project files.

• Fixed issue where negative legacy could be accumulated in DDC request statistics skewing efficiency numbers.

• UnrealBuildTool: Set -fno-delete-null-pointer-checks when compiling ms platforms with clang

• Address cases where it was possible to see objects still being loaded when searching for them from a postload function.

• Removed auto-creation of non-nullable properties.

• Fix for FString::ParseIntoArray when string to parse has a length of 0, but still has backing memory

• Fixed usage of FString::Printf without format arguments in Math header files.

• Fixed constraints in TFieldPath and TWeakFieldPtr to allow normal pointer assignment semantics.

• Fixed an issue where making a 0 byte length bulkdata streaming request would work correctly with IoStore but assert when IoStore is disabled.

• Fix potential deadlock and reduce latency spikes in the task system

• Ensure internal index is valid before resolving an FPackedObjectRef value from an object reference.

• Prevented TSharedFromThis from being placed on a UObject.

• Fixed some unexpected copies caused by trying to move a TArray into another with an incompatible allocator.

• Fixed conversions in enum serialization when the enum associated with an enum property has changed

• Fixed a visual bug in the debug console where the cursor position did not match up with the cursor indicator, due to different font sizes being used to calculate each.

• Fixed the comment of MakeShared about the use of non-public constructors when using emplacement functions, which conflicts with advice given elsewhere in the engine.

• Fix for AutomaticOptionalInclusion of a BP that depends on a native engine class resulting in a fatal cook error. We now explicitly check if the missing import is to a native type and suppress the error "Attempt to map an object during save that was not listed as a dependency".

• Use integrated terminal for VSCode

• Fixed remapping of lazy object ptr in PIE : now a default FGuid is remapped to default FGuid

• Fix GenerateClangDatabase

• Fixed static asserts in Cast which prevent casts of UObjectBase and UObjectBaseUtility.

• Fixing the way that we parse ini config overrides on the command line. This should now properly handle quoted values so long as they are not mixed with commas. Instead, it is recommended that each key/value pair be specified via its own -ini argument.

• Fixed dynamic delegate hashing of uninitialized padding in its GetTypeHash overload.

• Moved FConsoleManager to be actually private, just by moving the class decl into the .cpp. There were a lot of uses of #include "HAL/ConsoleManager.h" instead of IConsoleManager.h (and unknown number of licensee uses), so I left that file there and it just includes IConsoleManager.h now. - Fixed up a couple of uses of FConsoleManager when IConsoleManager is the correct usage

• Fixed constraints on TSharedPtr<>::operator*() and TUniquePtr<>::operator*(), which would fail to compile for types which overloaded the comma operator.

• Fixed GFPs failing to build their package localization cache when loading their asset registry data async

• Fixing a bug where we could try to reinstance CDOs asynchronously as part of live coding. This change ensures we finish all asset compilation before trying to gather the CDO references.

• Fixed a potential shutdown crash in the bulkdata registry.

• Makefile generator is now platform agnostic

• Project Generator for VS Workspace support

• Improved compiler error messages when using MemoryOps.h functions with incomplete types, e.g. when trying to instantiate the destructor of TArray<IncompleteType>.

• Move additional target compile args to after the file type specific args, so any previous arguments will be overwritten if desired, or if they need to be added after other args, such as args that depend on the cppstd version

• Fixed a lot of mismatched printf format arguments.

• Support ISPC multiple architectures in a single build

• Fixed an uninitialized invocation list lock count when move-constructing a TMulticastDelegate.

• Fixed the StdMalloc wrappers not being defined when FORCE_ANSI_ALLOCATOR is defined.

• Fixed TScriptBitArray breaking the ClearPartialSlackBits invariant

• Fix a use-after-free in the task system

• Fix crash when crash report upload response was null.

• PVS-Studio - SN-DBS integration fix

• Fixed TSoftObjectPtr being constructible/assignable from any UObject pointer type, not just convertible ones.

• Fixed cache policy merging for batched chunk requests in the DDC HttpCacheStore

• Fix missing ref counting in the runtime loader that could cause use-after-free.

• Fixed Clang complaining about deprecated enums when used with a TEnumRange.

• UnrealVS: Prefix encrypted Perforce server port address with "ssl:"

• Add missing memory barrier when pipe tasks finishes

• Fixed TNonRelocatableInlineAllocator::ForElementType::MoveToEmpty to leave the moved-from allocator pointing to the inline storage (like after a default construction) rather than unallocated heap storage.

• Fixed TUniqueFunction compile error when constructing one with an lvalue.

• Reduced delegate codegen by reimplementing TDelegateBase::CreateDelegateInstance as an operator new overload.

• Added TIsContiguousContainer specialization for TInlineComponentArray, so it can bind to TArrayView.

• Fix multiple race conditions that could lead to deadlocks in the task scheduler.

• Ensured that a non-const source argument in provided to RelocateConstructItems.

• [Rider] Fix IntelliSense by adding include order deprecation defines

• Fixed TWeakFieldPtr not supporting "const T" template parameters.

• \Fix bool ExecuteDBProxyCommand()

• Fixed FDateTime and FTimespan not serializing via StructSerializer.

• Fixed a compile error in TDeque when using an allocator with NeedsElementType == false.

• Properties that are EditorOnly and marked as part of a config are no longer skipped when not in Editor so standalone mode (-game) will be consistent with Editor and PIE.

• Fixed an issue objects loaded from a package would be marked as invalid for loading when garbage collected. This meant that until the entire package was collected, it was not possible to fully load a partially loaded package when using ZenLoader in Editor.

• Prevented Cast from being used on FFields.

• Disallowed boolean inputs to interp functions.

• Fix memory leak when waiting repeatedly on a task with a timeout.

• Fix potential deadlock in IoDispatcher at runtime on low core count systems

• Fixed inconsistency between EmptyString.ParseIntoArray(Array, DelimiterArray, 1, true) and EmptyString.ParseIntoArray(Array, DelimiterArray[0], true).

• Fixed a bug where UnrealVirtualizationTool invoking a child process would fail if the engine root path or the target project path has spaces in it.

• Make delegates in stat system thread safe .

• Fixed broken TMulticastDelegate move functions.

• Added missing FObjectPropertyBase::GetObjectPtrPropertyValue_InContainer overloads.

• AssetRegistry now properly removes redirects from GRedirectCollector when object redirector assets are removed. Added additional conditional timing scopes to registry to help identify stalls.

• OidcToken - Updated documentation with info regarding lack of support for Google based authentication and some suggested workarounds.

• Fixed the wrong object being validated in FObjectProperty::PostSerializeObjectItem.

• Adds missing GetId() member from TSet::TBaseKeyIterator. Without this implementation, it's not possible to use GetId() on TMap::TKeyIterators/TConstKeyIterators This missing implementation is specifically helpful for cases where you'd like to find the KV Pair ElementType for a given KeyArgumentType in cases where you may have collisions between keys and the actual KeyArgumentType value is important. Example case is when dealing with FNames in Editor since they compare on case-insensitive CompareIds but have unique DisplayIds for different casing. If you want to know the casing used when inserted into a map, you can now do the following: TMap<FName, FAssetPackageData*>::TConstKeyIterator It = CachedPackageData.CreateConstKeyIterator(PackageFNameOfAnyCase); FSetElementId Id = It.GetId(); if (!Id.IsValidId()) { return nullptr; } const TPair<FName, FAssetPackageData*> KVPair = CachedPackageData.Get(Id); FName PackageNameWithCasingUsedUponInsertion = KVPair.Key; return KVPair.Value;

• Made FUtf8String::Printf's and Appendf's formatting strings be ANSI, because there's no printf which takes a char8_t formatting string. UTF-8-formatted string arguments are still possible via %s.

• Fix TInstancedStruct assignment so Base = Derived assignments work

• Improved the robustness of bulk data streaming, and fixed an issue where zero size bulk data was not serialized correctly when loading

• Multiple fixes in pipe tasks when pushing tasks with prerequisites.

• Removed rehashing from key iteration, and mutability from TSet members, making TSet thread-safe for concurrent reads.

• Fixed FThreadSafeCounter64::GetValue() thread safety.

• Fix broken AnyTaskCompleted that didn't actually wait on any of the tasks

• Add architecture info to Rider project files

• Optimized TQuat::Slerp_NotNormalized(). Added startup tests to validate more completely.

• Fixed constness of FProperty* in TPropertyValueIterator.

• Completed the FObjectPropertyBase::SetObjectPtr overload set, which was only partially implemented before.

• Update NoExportTypes.h to add missing units, and to correct the order of units that were already there. This was breaking serialization of entries missing from the mirrored enum in NoExportTypes.h.

• Fixed EAutomationTestFlags to be an enum class of pure flags, so the flags are visible in the debugger.

• Allow Json object helpers to work with UClasses as well as UScriptStructs

• Fix: clang coroutine support when building with C++17

• Fix for buffer underrun in the Span and Region name generation

• Stopped TArray::RemoveAt() being called with a non-integral size argument, including EAllowShrinking.

• Fixed TIsValidVariadicFunctionArg failing to catch disallowed types in Printf-style functions accepting types which were convertible to allowed types but which weren't themselves allowed.

• Add the ability to add properties and their values in one operation to an FInstancedPropertyBag

• Fixed LiveCoding not detecting changes when working from vanilla editor

• Make FDoubleProperty and FFloatProperty use Verse's extensional float equality semantics, and support value hashing. This should only affect comparison of NaNs: the previous behavior was for them to treat NaNs as equal to all other values; the new behavior is to treat all NaNs as equal to each other, and unequal to all other values.

• Fix UScriptStruct::Serialize clobbering the saved struct flags on load for structs that don't have a matching CppStructOps.

• Fixed TStrongObjectPtr's comparison operators to follow normal pointer semantics.

• Fix incorrect call to AddStableReference on a stack variable

• Added bitfield text import and export support to FByteProperty with an enum, and fixed a bug where a getter wouldn't be used.

• Fixed a race in the legacy DDC API CachedDataProbablyExistsBatch

• Restore the Windows dll directory cache startup optimization that has been broken and was inactive in the previous release.

• Fixes for Rider project file generator

• Fixed TWeakInterfacePtr<const T> and TScriptInterface<const T>.

• Fixed class template argument deduction for TWeakObjectPtr.

• Added missing OutFailReason parameters to FJsonObjectConverter::JsonObjectStringToUStruct, FJsonObjectConverter::JsonArrayStringToUStruct and FJsonObjectConverter::sonArrayToUStruct.

• Fix wasting one cycle when starting GC async purge.

• Added REQUIRE_CHECK_SLOW to low-level test macros, that validates that checkSlow, checkfSlow... are called on configurations where they're effective

• Fixed property conversion to and from enums with bitfields.

• Push array inner property to current archiver state when serializing "replacement" array item value overrides on load.

Deprecated:

• Deprecated TEMPLATE_REQUIRES. UE_REQUIRES should be used instead, though the syntax is slightly different - see the comments.

• FCompression interface now has 64 compression interfaces that should be preferred over the 32 bit ones, which will eventually be deprecated. Note that the return value meaning has changed to allow for returning whether the compression failed independent of whether the output was actually compressed.

• Deprecated TIsTriviallyDestructible.

• PostLoadAssetRegistryTags has been deprecated. Custom implementations should be changed to be thread safe and implemented as ThreadedPostLoadAssetRegistryTagsOverride. This was necessary in order to support multithreading of the asset gatherer tick to improve editor launch performance.

• Added UHT support for UE_DEPRECATED(all, "...") macro, which is already used in the engine and will serve as a way to leave the UE_DEPRECATED mark on code that has been deprecated for more than 2 engine versions but has to stay in the codebase "forever" because it's reflected (UPROPERTY, UFUNCTION, UCLASS, USTRUCT).

  • Use case :

    C++

    // Let's say we've deprecated the following code in UE5.1
      UE_DEPRECATED(5.1, "Use the other thing instead...")
      UPROPERTY(meta = (DeprecatedProperty, DeprecationMessage = "Use the other thing instead"))
      float SomeUProperty_DEPRECATED = 1.0f;
      UE_DEPRECATED(5.1, "Use the other thing instead...")
      UFUNCTION(meta = (DeprecatedFunction, DeprecationMessage = "Use the other thing instead..."))	
      void FooBar(int32 X);
      // Then when shipping UE5.4, we would turn that into:	
      UE_DEPRECATED(all, "Use the other thing instead...")
      UPROPERTY(meta = (DeprecatedProperty, DeprecationMessage = "Use the other thing instead"))
    
    Expand code Copy full snippet(14 lines long)

  • Therefore, the act of deprecating code that is more than 2 engine versions old consists in a simple text-search for "UE_DEPRECATED" in your code and for the occurrences that are not tagged as "all" and more than 2 versions old. Then:

    • If the code is reflected, turn them into UE_DEPRECATED(all, ...)

    • Otherwise, remove the code altogether

• Deprecated calling AddSaveOverride on the context given to UObject::PreSave

  • You should override UObject::CollectSaveOverrides and call AddSaveOverride on its context instead

Dev Tools

New:

• [UnrealBuildTool] Added a bGenerateProgramProject flag to TargetRules, which forces a target to be treated as a program during project file generation.

• CSV Profiler: add support for aggregated task stats. This can be enabled via the cvar csv.AggregateTaskWorkerStats, which defaults to on. When enabled, stats recorded on task worker threads are aggregated instead of outputting a single stat per thread. This reduces CSV size when there are large numbers of worker threads, and makes stat data more intelligible. The stats appear with an AllWorkers prefix instead of the individual thread name.

• Add support for the OptimizationLevel param for Clang-CL (so -Oz is used for OptimizeForSize etc). This includes optimal flags for PGO, since -Os tends to be the fastest option there (in addition to being smaller)

• Updated the logging for mismatched build settings that require UniqueBuildEnvironment to show the values that don't match

• Added more metadata information into UnrealInsights trace scopes:

  • Package name in AsyncLoading (for LoadTime channel)

  • Statemachine name during GameFeaturePlugin transitions.

  • Marked GC region

• Added ability to read plugins into a config hierarchy, controlled by passing optional IncludePluginsForTargetType param to ConfigCache.ReadHierarchy(), with a TargetType (like Game or Editor). - Use this in CopyBuildToStagingDIrectory when reading the Packaging settings when staging. This allows plugins to add files/directories to stage without needing to modify every project. - Added a ConfigTester Turnkey command that can help test C# inis programmatically. Currently need to pass in these 3 params on commandline, it doesn't ask for them: -Branch=Engine -Section=SomeSection -Key=SomeKey

• Allow for -ActionTypeFilter to BuildMode, which will make only certain action types to run

• [UnrealBuildTool] Added a bAllowEnginePluginsEnabledByDefault field to TargetRules, which is analogous to (the inverse of) the "DisableEnginePluginsByDefault" field in uproject descriptors.

• CsvProfiler - Report explicit event wait names as trace scopes.

• Added a shared GetEditorForProject() function which should be used in UAT to get the path to the binary to run, becasue UnrealEditor-Cmd.exe is not always correct (if the editor is a Unique build environment, the editor to use to cook etc is the project editor, not UnrealEditor)

  • Passing in "null" for a lot of UnrealExe params, instead of "UnrealEditor-Cmd", to allow GetEditorForProject to be called (we must still allow for a true override, so we can't get rid of the param)

  • Added FileSystemReference.Exists

• Added source location tracking for async load requests that do not have debug name specified

• Added support to OutputLog to only have the TargetDevice functionality if DeveloperTools are included in the target (so programs can use it without needing to pull in the whole mess that is TargetPlatform)

• Added a method for Shared build environment builds to have certain modules marked as caring about SDK version overrides for some platforms - if any of those platforms are overridden, the DLL will be written to the project Binaries dir instead of Engine (set bAllowSDKOverrideModulesWithSharedEnvironment = true in a Target.cs) - Added ability to optionally skip SDK validation when making a Target instance even if we don't want to skip Target validation (used when we make the base UnrealEditor target to compare to project's Editor target - we don't need to manage SDK for that temporary UnrealEditor target). - ShaderCompileWorker is now BuildEnvironment.UniqueIfNeeded, which will build into the project binaries dir if needed (based on per-project SDK override) - UnrealPak is marked as not caring about an SDK versions so it can be built along with SCW that does care - Added $(BinaryDir) variable to UEBuildTarget, etc, for the location of the first Binary in the output binaries

• Allow to disable _callstack trace _channel and not pay for backtrace overhead, which can be very costly on some platforms.

• Added ListShaderLibraries _and _ListShaderMaps commands that let you analyze the memory footprint of those structures. Requires r.TrackShaderMaps cvar to be enabled and for build target _bTrackRHIResourceInfo _set.

• Set all *TargetPlatform.Build.cs's to set the new SDKVersionRelevantPlatforms list so that per-project SDK version overrides will compile unique versions of those modules when that platform's SDK version of overridden

• Expose memreport metadata generation to the UEngine interface.

  • Also expose DoGameSpecificBugItLog in CheatManager

• Added client-side stat for IRIS active replicated object count

• Experimental release of Automated Perf Testing Plugin v0.1, providing Gauntlet Test Controllers, UAT Test Nodes, and BuildGraph macros for adding common automated performance tests to a project's automated build and test.

  • Currently supports static camera, sequencer, and full-screen quad material tests, with options to output via Insights, CSV Profiler, and FPS Charts.

• Disable hitchdetector when LLM is enabled unless -_DetectHitchesWithLLM _command line parameter is specified. It is expected that LLM capture adds CPU overhead during captures, hang/hitch detection made things just worse by spamming logs with unhelpful info.

• [UnrealBuildTool] Added a bExplicitTargetForType flag to TargetRules, enabling targets to opt out of being considered by GetTargetNameByType. This enables the introduction of new, narrowly-scoped TargetType.Editor targets, without introducing an ambiguity around existing -TargetType=Editor invocations of UBT.

• PerfReportTool: Add support for stat type qualifiers in summary tables so we can identify stats by their type to avoid ambiguity, e.g [meta]deviceprofile. Prefixes are : [metric] [csv] [meta] [toolmeta]

• CSVToSVG 3.61

  • Add -startEvent and -endEvent params to start and stop graphing at a particular event

  • The params -startEventOffset and -endEventOffset allow you to offset the start/end by a particular number of frames

• PerfReportTool v4.236.0 - Added Wildcard Stat support to BoundedStatSummary. This allows ReportTypes.xml to specify '*' for generated columns in a summary table. The tool will now attempt to match that wildcard to all possible stats, generating new columns for each. Wildcard symbol needs to be provided in the column name, summaryState name and stat name, or it will skip that stat name. Supports otherStat as well so can be used with the Ratio formula. [RN] PerfReportTool v4.236.0 Added Wildcard Stat support to BoundedStatSummary. This allows ReportTypes.xml to specify '*' for generated columns in a summary table

• [AutomationTool] MakeCookedEditor now allows subclasses to override ProjectParams construction.

• CsvToSvg - Improvements to event formatting in graphs

• Adding a macro called "AdditionalTestNodes" to BuildAndTestProject which can be extended via a file include "AdditionalTestNodesExtendFile" in order to inject additional test nodes attached to the existing per-platform/per-configuration test agent.

• CSV Profiler - Add ProgramSizeMB metadata so we can capture this even when LLM isn't running

Bug Fix:

• Scope filesystem callbacks to shader code into Shader LLM, added more asset tags

• Restore behavior of MemReport -full by duplicating the list of commands from default profile.

• UHT will now generate valid code if the header file had multiple '.'s in the file name.

• Fixed UHT code generation to support enums with no enumerators

• Fix issue where a TInstancedStructs property wasn't setting the meta data in the correct place when used with a container such as TArray.

• Fixed typo in the centimeters per second units in UHT.

• Fail gracefully if we fail to allocate TLS data for the CSV profiler

• Remove FName block allocations and TextureManager construction from contributing to the MemQuery/Memtrace asset memory cost readings

• Live Coding should no longer crash when patching headless editor instances

• Fixed UnrealVS hanging on start-up due to unexpected load order with initialization.

• Mark more SceneRender reallocations with correct LLM tag instead of EngineMisc and other random tags

• CSV Profiler : Fix a crash related to SetWait

• UHT will generate an error if an IInterface is improperly used.

Horde

New:

• Horde: Add missing documentation for windowSize parameter

• Horde: Separate out log event warnings and errors into a separate fingerprint when we exceed the 25 event limit in the Hashed Issue Handler.

  • This means that any newly introduced errors will not be merged into an existing issue if it only comprises of warnings.

Bug Fix:

• Horde: Make horde chunk boundary calculation consistent with unsync, add unit tests to validate determinism

Insights

New:

• Add command line override for sponsor mode for UnrealTraceServer.

• Rearrange TraceLog message types and emit fatal error for OOM.

• [Insights] Add TimingInsights.ExportTimerCallees command to export the callee tree of the provided timers.

• Extended the Timing Regions Trace API to allow closing regions by ID. This allows multiple timing regions with the same name to overlap and be uniquely identified.

• Adds a control layer for Trace (TraceService) and a controller (TraceController) integrated into SessionServices module. This allows remote control of tracing over messge bus.

• Improved "Export memory snapshot". - Added Package, _AllocThreadName _and _FreeThreadName _columns to the exported table - Use filtered table result instead of all nodes as a datasource

• Output TraceLog control port in log When running multiple instances on one the same machine TraceLog searches for an open port to listen to control commands, but there was no way for the user to know which port each process ended up using. Add log entries that print the final listening port.

• Allow Unreal Insights to connect to non-standard control ports When running multiple instances on the same machine, TraceLog listening port will be different for each process. Allow the Unreal Insights connect UI to use non-standard ports by specifying "ip:port" format.

• Add Trace Pause/Resume menu entry to the Trace Editor Widget.

• Preset for "light" memory tracing. In certain scenarios it can be useful to trace detailed allocations, but without paying the cost of recording callstacks and instead rely on tags for analysis. Enable light memory tracing by starting the process with -trace=memory_light.

• Add option in UnrealTraceServer to detach from current console. Automatically apply this option when launching a forked server to avoid stopping the process when terminal window closes.

• Add more descriptive tooltips to the channels and to the Screenshot,Bookmark and Region menu entries in the Insights Status Bar Widget.

• Added Unreal Insights support for tracing memory page swap events

• Added Branch and Version columns to session browser

• NetworkInsights - Detected lost packets are now marked on incoming data - Changed how we display lost data to make it easier to spot.

• Adding controls to the Insights status bar for to beginning/ending a trace region in the editor

• Trace autostart for Mac/Linux. Applications can now automatically start tracing whenever Unreal Insights application is running. The behaviour can be controlled using the UI in Insights session browser or by starting the application with -traceautostart=x.

• Adding Trace Screenshot BP node to the Trace Utilities plugin

• When using "-tracehost" command line argument without specifying a hostname, default host will be 'localhost'. This is analog to how the "-tracefile" arguments work.

• Added Trace.RegionBegin command

• Added Trace.RegionEnd command

• These commands allow developers to manually tag regions of insights traces with custom names.

• UnrealInsights - Add 'Copy Name To Clipboard' context menu option.

• Improved SessionBrowser selection and expansion. Added text about the need to run with (-messaging) for sessions to be shown in SessionBrowser. Changed SessionBrowser row colouring and alignment. Disable auto selection of current session in Unreal Insights Frontend. Widened the channel list columns.

• Added the ability for Unreal Insights to resolve symbols for iOS using psym files

Bug Fix:

• [Insights] Fixed timing regions emitted from SlowTask to use unique ids. Matching by name was not reliable when multiple slow tasks with same name are active at the same time.

• Fix for trace snapshots on platforms that use internal send buffers. When a trace was active and a snapshot was triggered the send buffer could be flushed while writing the snapshot, making the ongoing trace miss events.

• Renamed the "LoadObject" named event (defined by SCOPED_NAMED_EVENT) as "StaticLoadObjectInternal" (measures time in StaticLoadObjectInternal() function) because there is another "LoadObject" cpu scope (defined using the UE_TRACE_LOG_SCOPED_T macro; the one with metadata) which measures same function.

• Fix crashes in UnrealInsights when cache size grew too large.

• Fix crash when UnrealTraceServer on Linux was looking for user home directory.

• Do not reset bytes traced statistics on new connection

• Correct how we now can return the original allocator from MemoryTrace_CreateInternal. This fixes incorrectly trying to hook virtual memory allocators on Windows when memory tracing is disabled.

• Remove screenshot options from Insights status bar when feature is disabled.

• Fix bug in UnrealTraceServer on Windows when launched by a process with elevated privileges and used as sponsor process. UTS was not able to open a handle to the sponsor which resulted in immediate exit.

• GpuProfiler: Support gpu trace events named with the <basename>_N pattern, where N is some integer. Before this fix, Gpu trace events with said naming pattern would all appear with the same name, which would correspond to the first one. e.g. VP_0, VP_1, VP_2 would all appear as VP_0 in Unreal Insights. This is because the event is being sent as a uint32 corresponding to the ComparisonIndex of FName, which is the same for the above naming pattern - the N ends up encoded in the Number of the FName, corresponding to the instance number.

• Fix narrowing of store directory string. At one point it was assumed that store directory would only ever be limited to ANSI. The selected directory string was narrowed before being sent to UnrealTraceServer.

• Emit error message if TraceLogs redirect buffer is full.

Deprecated:

• Marked all the Profiler* modules (Profiler, ProfilerClient, ProfilerMessages, ProfilerService) as deprecated. If another module depends on one of these modules a warning message will be triggered by UBT. The old Profiler is actually deprecated since UE 5.0, superseded by Trace/UnrealInsights.

Unreal Build Accelerator

New:

• Added User and Build UBT/UBA Metrics to Horde Analytics

Framework

New:

• Improved error messages when we skip loading a package during import because the plugin wasn't mounted. The plugin manager and the GameFeatureSubsystem now have an opportunity to provide additional information to the user about why the plugin wasn't loaded or the package wasn't found. This information is provided in the Message Log and output log.

• Fixed potential recursive out-of-memory/corruption crash due to memory allocations in the crash handler.

• Added ability to Gauntlet's Heartbeat system to track all client apps

• Added thread manager interface for retrieving callstacks without incurring additional allocations (which will be used to avoid failing to allocate memory while crashing out of memory).

• Factor FGameFeaturePluginTemplateDescription into it's own file

• UBT will now write out the BuildPlugins names to correctly ignore optional plugins in the editor

• Plugin templates can provide an optional default plugin name to use when selecting the template in the plugin wizard

• Removing IniCacheSet usage in plugin manager; the set doesn't actually get propagated in the ParallelFor below where it is currently used (and doesn't save much in normal circumstances either).

Bug Fix:

• Follow-up fix to a linker error from CL 27595673 that was reported by a licensee.

  • If you created a custom class derived from ALight, there would be a linker error reporting a missing definition of ALight::PostLoad. The vtable of a derived class needs to call PostLoad, which requires that the symbol has been exported.

• Improved ZipArchiveWritter ZIP64 handling of header output so that is outputs valid zip headers which prevents issues with some zip extration tools

• Fixed linear extrapolation in SplineMeshComponent by using the positions at MinT and MaxT instead of the Spline StartPos and EndPos respectively

AI

New:

• [NNE] Extended NNERuntimeORTDml to implement NPU runtime interface.

• Add ability to search for blackboard keys and gameplay tags in the behavior tree editor

• Prevent move or copy of FWorldConditionContext and FWorldConditionContextData

• NNERuntimeORT upgrade ONNX Runtime to version 1.17.1 and its required dependency DirectML to version 1.13.1.

• Create BlackboardKeyType_Struct and associated ValueOrBBKey_Struct

• Create StateTreeMoveToTask wrapping a UAITask_MoveTo allowing state tree to move AI using the same framework as BehaviorTree Create the FStateTreeAITaskBase & FStateTreeAIActionTaskBase state tree task namespace for AI focused ST task

• Our plugin NNERuntimeORT already includes a DirectML runtime that implements the GPU interface for neural network inference outside the rendering of a frame. We implement the necessary infrastructure to let this backend also implement the RDG interface for in-frame inference, providing a fast and powerful execution provider on DX12 based desktop systems.

• Create BTTask_RunStateTree and BTTask_RunDynamicStateTree that allows the execution of state tree in a behavior tree

• Introduce FValueOrBBKey_X, a Default Value/Blackboard Key pair for BTNodes with a custom view to make picking key easier FValueOrKey are created of each of the engine blackboard key types.

• Added an editor accessor for the FullNodeMap

• NNEDenoiser: Upgrade OIDN models to version 2.3.0.

• NNEDenoiser uses NNERuntimeORTDml on RDG as default.

Bug Fix:

• [Learning Agents] Fixed MaxAgentNum bug with manager component not working on spatially loaded actors

Deprecated:

• Removed NNERuntimeRDGDml, please use NNERuntimeORTDml (on RDG) instead.

AI Behavior Trees

New:

• Stop BT in UGameplayBehavior_BehaviorTree on abort

• Clean up GameplayBehavior_BehaviorTree on ctrl teardown A cancelled behavior now explicitly stops the tree to not let it run until another different BT is pushed. It also solved the issue with repeated execution requests of the same BT asset that will fail as the component would think it's already running it. Listen to possessed Pawn changes to prevent leaving the behavior running which could cause a resource leak and an ensure in OnTimerTick.

• Blackboard now uses DuplicateObject instead of NewObject when instantiating a key so all default values are properly copied.

• Composite BT node memory lifecycle methods are now exported as part of the API

Bug Fix:

• Updated TimeLimit Decorator to not get get ticked again in case it is still active after requesting execution (e.g. latent abort)

• remove any scheduled updates when the tree is stopped

AI Debugging

New:

• Rewind Debugger: Add support to specify trace filename or host in RewindDebugger.StartRecording

• VisualLogger

  • Removed ensure on the Editor world when getting timestamp since it might be called while it's getting garbage collected

  • Added GWorld as a fallback in GetWorldForVisualLogger

• Added option "Slot Details" to be able to reduce the amount of replicated data for worlds with large amount of SmartObjects.

  • This option is required to display annotations (i.e. turning it off will disable annotations and turning on Annotations will turn this one on)

  • When turned off, a single shape will represent the SmartObject in the world

• Prevent Visual logger rendering actor from being selectable and showing up in the scene outliner

Bug Fix:

• Fixing up a regression in the Visual Logger where Actors failed to have unique names with bForceUniqueLogNames set.

• If the Gameplay Debugger is active while quitting, then restore the temporarily disabled GAreScreenMessagesEnabled flag (which allows messages to log to the screen). Previously, quitting the game (e.g. ending PIE) while the Gameplay Debugger was active would prevent further messages from being logged to the screen in subsequent plays.

• Wrong definition of macro UE_CVLOG_CIRCLE_THICK Visual Logger

• Improving ListenServer mode support for GameplayDebugger.

Deprecated:

• Deprecating old FVisualLogger::GetEntryToWrite in favor of a new, static FVisualLogger::GetEntryToWrite for consistent Engine Timestamps in Editor.

AI EQS

Bug Fix:

• Allow EnvQuery TraceByProfile to set the shape of the trace used.

• Fix EQSEditorModule custom Toolbar Extenders not being applied

AI Navigation

API Change:

• SetConfig should now store the properties supplied for registering the navdata in the NavAgentProperties. NavAgentProperties will be used as the agent mapped to the navdata for registering/unregistering with the navigation system.

New:

• [Navigation] Added a query to ANavigationTestingActor to display if navigation data is ready (if it has been generated) within a given radius.

• Addition of a Boolean to track if a navmesh has been loaded without it's tiles and update the display so it shows as needs to be rebuilt (can occur when undoing a navmesh).

• Addition of a "Navmesh needs to be rebuilt" message to the navigation display since the stat display is not always enabled.

• [Navmesh] Added more information when reporting the error message related to the TileNumberHardLimit.

• [Navmesh] Added more information when reporting the warning message related to the tile pool size.

• [Navlink] Added custom link owner's name to the link ID warning to allow identifying the problematic actor.

• [Navigation] Improved AStar log readability and added details when filtering nodes.

• [NavInvokers] Optimization: avoid reserving local containers every frame.

• [NavInvokers] Added a profiler tag for more precise tracking.

• GetEdgesForPathCorridorImpl is no longer inlined so that derived classes of ARecastNavMesh can call the function.

• [Navmesh] Added display of heightfield layers to the tile debug display.

• [Navigation] Clarified UAITask_MoveTo params.

• Change NavLinkProxy to update navigation data in PostEditChangeProperty similar to what is done in other navigation code.

• [Navmesh] exposed GetPolyWallSegments to game code via ARecastNavMesh

• Replaced custom NavLink static registration queue by a new world subsystem that will also store NavRelevantObject that are not AActor/UActorComponent based. This change allow new NavigationSystem created after initial map load (e.g. ANavSystemConfigOverride) to properly recreate its custom nav link mappings and octree.

• [NavInvokers] Optimization: now using a map instead of an array to avoid high cost as invoker usage scale up.

• No longer add AI and Navigation systems when creating inactive world with physics

• [Navmesh] Added a NaN check to dirty area bounds.

• Added early warning for invalid bounds when creating FNavigationDirtyArea.

• [Navmesh Generation] Removed MaxVerticalMergeError and instead prevent point merging when adding raw contour points if simplificationElevationRatio is being used.

• Updated some NavigationSystem method display names to be consistent with other BP exposed functions

• [Navmesh Generation] Fix contour simplification to be symmetrical when using SimplificationElevationRatio.

• Exposed RequireNavigableEndLocation to MoveToLocationOrActor BP function.

• [Navmesh] Optimization to simplifyContour.

• [Navmesh] Removed deprecated FRecastNavMeshGenerationProperties.

Bug Fix:

• [Navmesh] Refactor to keep solidHF and compactHF for the lifetime of FRecastTileGenerator.

• [Navmesh] Changed ARecastNavMesh "Draw Failed NavLinks" debug name to "Draw Failed and Valid Links".

• [Navigation] Fixed Recast AStar log name.

• [Navmesh Generation] Fixed issue where polygon would wrongly connect to a different height, resulting in a broken navmesh surface.

• [Navmesh] Fixed IntCastChecked assert caused by invalid location, tiny tiles or giant invoker radius.

• [Navmesh Generation] While adding raw contour points, use the height from the highest connected corner cell.

• Fixed RecastNavMeshGenerator to use TotalNavBounds when IsValid is 'true

• Fix security issue:

  • Memory Corruption in SimpleCellGrid::Serialize() Due to Missing Bounds Check and Integer Overflow.

  • Make sure DataBytesCount is computed from width and height and prevent width*height from overflowing.

• Fixed missing NavigationData cleanup when cleaning up the whole system. When a NavigationData is either EndPlay or Destroyed it unregisters itself from the NavigationSystem and perform its cleanup. Problem was that when the whole system is doing a cleanup in response to OnWorldBeginTearDown it was only unregistering without performing the cleanup.

• [Navmesh Generation] Fixed:

  • When removing poly, make sure that the totality of the replacement poly is copied.

  • When looping to see if vertex have been flagged for removal, stop the loop to prevent the flag from being reset.

• Bug Fix: Fixed an issue where navmesh won't be updated if the user manually calls SetStaticMesh() function on a collision-disabled StaticMeshComponent

• Fix crash when generating navmesh tiles if DirtyLayers has not been initialized.

• [Navmesh] Fixed tile portals not connecting caused by picking opposite portal direction (on an edge above or below) when building mesh adjacency. This fixes issues seen in stairs where the stair corridor can be blocked by a hard edges when edges between layers do not match perfectly.

• [Navlink] Avoid registering link proxy with invalid id.

• Bug Fix: Fix issues that Navmesh Generation for Brush actor isn't correctly updated after some operations.

• New: Added a console variable brush.ForceNavmeshGenerationOnStaticBrush to enable/disable the effects of Navmesh Generation relevant flags on Brush Actor.

• [Navmesh] Fixed crash in ARecastNavMesh::FindPath when NavData is missing from the query.

• [Navmesh] Fixed cylinder collision wrongly offset when used as navcollision on dynamic obstacle.

• Fix issue where AgentToNavDataMap entries were not cleaned up properly due to ARecastNavMesh updating its config to have a valid agent step height if the step height was not overridden.

• NavigationTestingActor: Don't reset ShowStepIndex for every request and allow to save it's value (not transient anymore).

• [Navmesh] dtBuildTileCachePolyMesh fix: while removing vertices, fix addition of an extra point to the contour since it can break the triangulation and result in missing polygons.

• [Navmesh] Fix crash in ARecastNavMesh::FindEdges when RecastNavMeshImpl is not valid.

• Bug Fix: Fixed an issue where navmesh generation for HierarchicalStaticMeshComponent won't be updated correctly on certain operations.

• New: Deprecated some APIs in HierarchicalStaticMeshComponent

• [InstancedStaticMesh] Fixed partial navigation update for Editor manipulations

  • added partial update on component registration/unregistration

  • skip updates when adding/removing instances when component is not registered

  • added list of dirty areas to pending dirty element so they could be applied when udpate info is successfully processed

  • added some missing updates when not using partial updates

• [WP Navmesh] Fix and simplify WorldPartitionNavigationDataBuilder clean packages process and removing dead code.

  • Issues could occur with wrongly generated packages, now the chunks will be deleted regardless of their spatialization.

• Bug Fix: Fixed an issue where InstanceStaticMeshComponent with odd numbers of negative scale axis didn't correctly generate navmesh

• [Navmesh] Tiles are not saved during undo redo operations anymore.

• OnNavigationBoundsUpdated, make a removal request if the bounds are invalid.

  • This avoids having invalid RegisteredNavBounds when undoing the addtion of a NavMeshBoundVolume.

• Fix possible crash for an invalid navmesh in AdjustLocationWithFilter.

• [Navmesh] Fixed crash occurring when undoing removal of ARecastNavmesh.

• Fixed crash in NavLocalGridManager when invalid parameters are provided

• [Navmesh] Fixed crash when changing TileSizeUU value.

• [Navmesh] Fixed debug display issue in duDebugDrawHeightfieldLayer

• [Navmesh] Added ensure for TileSize != 0 and for the range of the tile coordinates.

AI Perception

Bug Fix:

• Fix Crash in UAISense_Sight::Update

AI Smart Objects

New:

• Definition asset can no be longer be changed when component is bound to the simulation.

• Cached variation is now reset when changing the asset definition

• GameplayInteractions Plugin - UAITask_UseGameplayInteraction task success is now based on StateTree end result.

• Adding support for SmartObjects on instanced actors using tag and fragments to create/destroy smart objects for mass entities

• Owner actor is now provided to FindSmartObject in EQS query generator

• Allow smart object creation from definition, transform and owner descriptor struct that will use dynamic IDs

• Replaced registration type WithCollection by BindToExistingInstance in USmartObjectComponent since it can also be used for objects not tied to a component lifetime created from CreateSmartObject

• Allow subsystem component accessor to force hydrate the actor associated to a smart object

• Use sweeps instead of line traces to detect ground on exit. This prevents line traces from missing geometry when objects are perfectly aligned

Bug Fix:

• Change BP function library's Mark Slot as Occupied to return the result of the subsystem's Mark Slot As Occupied when it is called.

• Clear cached asset variation when the base asset gets saved

AI State Tree

New:

• enabled debugger on all desktop platforms

• New: Add buttons for creating new state tree nodes blueprint classes

• New: Added Random Selection Behavior for State Tree

• Create state tree task Run Parallel tree allowing a state to run a subtree while child state can still to be selected and entered.

• New: Added Browse to Blueprint and Open Blueprint buttons for State Tree Nodes

• New: Added Utility-based Selection Behaviors in State Tree.

• New: Added Weight variable and a new type of State Tree Node named Considerations used by the aforementioned Selection Behaviors.

• New: Added relevant UX features.

• Extend FStateTreePropertyRef to be able to bind to multiple property types

• StateTreeDebugger buffered data now handled differently if it can be reused in multiple traces during the same game session or if it needs to be reset when stopping the trace

• Create IStateTreeSchemaProvider that allows a derived class to override the schema used by a parent property. Create StateTreeAIComponent & StateTreeAIComponentSchema derived from StateTreeComponent but guaranteed to have a AIController

• StateTreeDebugger

  • New recording started from the debugger will be selected as the new active analysis

  • Allow multiple recordings during the same PIE session to reactive existing tracks

  • Do not apply trace selection if user reselect the current trace to avoid clearing data

Bug Fix:

• Fix nullptr error for invalid StateTreeRef

• Bug Fix: Hid "IsTrue" option for operator on State Tree Conditions because it's not applicable

• Fixed debugger timelines reused for the same instances through multiple traces taken during the same game session

API

New:

• GameFeatures API: Add the OnGameFeatureActivated callback to trigger only once a Game Feature Plugin is completely active; For when some observing system relies on a plugin being fully active and not in the process of activating.

Audio

New:

• Added two new Modulation functions on the Audio Component: Add Modulators and Remove Modulators.

• Added experimental Control Bus Dashboard to Audio Insights. To view it, set the console variable au.Modulation.AudioInsightsTab to 1.

  • This tab is a work in progress, but the implementation serves as an example if you want to build dashboards for your own tools.

• Asynchronous loading added to Soundscape Palettes

• Added a new CVar to force Spatialization Plugin Submix to send directly to main submix instead of the user set Default Submix: au.IgnoreUserResonanceSubmix

  • This CVar is part of a fix for a very specific edge case involving Audio Modulation, Submixes, and External Spatialization plugins (eg. Resonance), which sometimes resulted in submixes' Volume Modulation being applied twice.

• Remove tick from UMetaSoundOutputSubsystem, only drain queues when there is new data.

• Newly created Control Buses now default to using the Volume Parameter.

• Make subdivision trigger and pulse generator work the same way.

• Added a CVar to Enable/Disable Audio Modulation: au.EnableAudioModulation

  • Setting this CVar at runtime freezes the state of the entire Modulation System. Launching with this CVar means that no modulation assets will ever be created or updated.

• Added highpass filter to Audio Component.

• This performance improvements vastly increases the allowable size of a live auditioning MetaSound Source before clients experience audio dropouts.

• Added Shared State Behavior input to MetaSound Array Random Get node for control over how random state is shared between nodes

• Relative Render Cost estimates the instantaneous cost to rendering a MetaSound in a cross platform way.

Bug Fix:

• We have fixed a minor bug in the Ogg Vorbis audio compression implementation that meant a single data frame of data was lost at the end of the stream. This bug presented mainly for highly compressed low bitrate single channel audio where a single data frame could contain multiple seconds of audio.

• Added Audio Component ID to spatialization plugin data when using external Spatializer

• Fixed an editor crash in City Sample related to audio.

• Fixed a bug where IsControlBusMixActive sometimes returned true after the bus mix was deactivated.

• [Harmonix] MIDI Note Trigger node: set note number only on note on. This will avoid issues with downstream patching that might behave badly when a note is transposed on the way in, but not on the way out. Step Sequence Player node: don't worry about setting a transposed note number on note off messages. The voice id of the message will be enough for downstream code to respond appropriately. #virtualized

• Fixed a bug where Wet and Dry Submix Modulation incorrectly used Output Volume Modulation Settings, causing blueprint setters to not work properly.

• Fixed crash when applying Modulation to a Source Effect's parameters at runtime.

• Duplicated audio data when reading from memory mapped files

• Improved thread safety of Audio Modulation's internal ID generation.

• Fixed a bug where Modulation LFO Generators occasionally did not Activate

• Allow MetaSound member default literal values and certain member fields to be copy/pasted in the details panel

• Fix frequency clamp and interpolation in MetaSound Low Pass Filter node

• Fix MetaSound trigger parameters being retriggered on realizing virtualized sounds and unneeded parameter updates being cached while virtualized

• Enable pasting objects and object arrays from the content browser and Blueprint into MetaSound default values

• Fix namespace being lost when select click renaming MetaSound graph members

• Fix MetaSound Array Random Get node causing unintended repeats in some cases with shared state

Blueprint

API Change:

• Use FunctionReference.GetMemberParentClass() to query characteristics of the underlying function used by the node.

New:

• Make FKismetCompilerUtilities::GenerateAssignmentNodes callable from other sources The logic of GenerateAssignmentNodes does not require a Call Function node, only that the input has a "then" pin which is not required by all Call Function nodes. Making this less restrictive makes it easier to write new custom K2 nodes based on or similar in functionality to CreateObjectFromClass without requiring a Call Function node is the source of the object.

• Extend the K2Node_Event API to include a GetDelegatePin function

• UK2Node_ConvertAsset improvement Adds two functions to the UK2Node_ConvertAsset implementation that act as accessors to the pins created by that node.

• Add the ability to set DeprecatedFunction="Note" (and DeprecatedVariable) metadata in a class header to lower the severity of a blueprint deprecation message. This can be used for "soft" deprecations where the function still works but should not be used in new blueprints.

• Native support for UK2Node_AsyncAction Adds function to UK2Node_AsyncAction so that its members (really protected members of UK2Node_BaseAsyncTask) can be initialized properly from native. We can also do this via node spawners, but they tend to be clumsy when spawning async action nodes as intermediates.

• Editor scripts can now add variables to blueprint assets using AddMemberVariable

• Remove unused line in EdGraphSchema_K2.cpp

• Deprecated redundant fields in UK2Node_CallFunction. Both bIsConstFunc and bIsInterfaceCall are unnecessary since we can simply query the underlying UFunction/UClass (via FunctionReference) to determine if we're dealing with a const function or an interface class. Additional changes:

  • A check for CLASS_Interface was added to UK2Node_Message. While the chances of hitting this are very low, it wouldn't make sense to reference a non-interface class when expanding this node. It should really error out in that case.

  • CreatePinsForFunctionCall had an unusual check for hiding the self pin if the pure function was non-const. This appears to be really old and no longer relevant.

Bug Fix:

• Blueprint MemberReference now also looks for DeprecatedProperty meta

• Ensure that function parameter names can't be renamed to any local variables. We already have a check that prevents renaming local variables to parameters, but we don't have the opposite check. Since renames first test the pin rename with RenameUserDefinedPin, we need an implementation in the function entry node that ensures that the new name doesn't collide with the local variable names.

• Fixed reachable garbage issue involving UInheritableComponentHandler::UnnecessaryComponents

• Fix crashes when reconstructing blueprint instances while using less common patterns of level loading

• Fixed an editor crash that could result during propagation of a PostEditChange() event after modifying a nested struct member field on an archetype.

• Fix data loss bug where changes to placed and inherited blueprint components could be lost if they override the parent actor class but used the same values as the component blueprint class.

• ExposeOnSpawn Class properties now respect "none" value inputs on "Construct object from class" nodes

• Blueprint Add Custom Event unable to resolve delegate signature inside a split struct The pin splitting logic didn't propagate the underlying member reference for the function signature of a delegate. CreatePin doesn't handle this automatically, so we need to copy over the information manually.

• Fix several bugs when using ClassWithin on blueprint classes. It now properly updates blueprints when the native class changes and errors will no longer crash the editor

• Make sure we clean up constructed components when using the Actor replacement workflow.

• Comment Node doesn't update in the Bookmarks tab after being renamed in the Event Graph Anytime a node's title is changed, we need to refresh the bookmarks tab.

• Fix it so ExposeOnSpawn parameters set on a create/spawn blueprint node are correctly compared against the class's default values. It will only override values that could possibly be different from the defaults (including all values that could change at runtime due to pin connections).

• Derived struct data is not copied to base struct. We made Generic_SetStructurePropertyByName a bit too strict by only allowing structs that matched exactly for copying properties. Prior to the change, this function was incredibly lax by allowing completely unrelated structures to be copied. The appropriate middleground allows derived structs. While this may lead to object slicing in some instances, this is permissable. Additionally, removed the public-facing Generic_SetStructurePropertyByName function since it was deprecated.

• Update TryFreeCDOName() to check the renamed default object name and not the current default object name. The PR fixes TryFreeCDOName, but this change includes some additional cosmetic changes to RenameGeneratedClasses (inconsistent whitespace, missing consts, etc).

• Adjust FKismetCompilerUtilities::GenerateAssignmentNodes to ignore output pins GenerateAssignmentNodes gets confused by the existence of a pin who name matches a property name but cannot be connected to an assignment node input.

• Fix data loss bug where changes to placed components of inherited blueprints could be lost if the child blueprint did not modify that component in any way

Blueprint Compiler

New:

• Blueprint macros can now infer more than one type of pin, especially useful for TMap related macros

Bug Fix:

• Fixed cause of Blueprint Macro Library Macro Graphs remaining in the Blueprint asset after said graph was deleted by the user

• Fixed updating of objects that only reference a blueprint or its instances via weak references

• Fixed underlying cause of "Content is missing from cook" error when cooking deep blueprint hierarchies with components

• Fixed one cause of phantom blueprint compilation errors after duplicating a blueprint graph

• Dependent blueprints are automatically included in the compilation set when they are out of date, this fixes some obscure crashes during blueprint compilation

• Allow structs in the error state to be contained in other structs in order to prevent cascading errors

• Empty event graphs are now more aggressively pruned, can be disabled via [Blueprints] bDisableLateEventGraphPruning

• Blueprint 'Switch' nodes now raise an error when their enum disappears

Blueprint Editor

New:

• Reference parameters in blueprint functions can now be tagged as const, preventing mutation within the function's graph

• Further optimized the Blueprint Editor's graph context menu, used to place nodes into blueprint graphs

• Removing the usage of "Friendly Names" from the Functions and (Event Graphs/Overrides Menu). The reasoning is that there is a long-term goal of removing Friendly Names entirely from the Editor. It interferes with the users being able to properly name their Functions/Events and have that name consistent through the interface. We have kept the Friendly Names when calling a function in Blueprints as well as the Blueprints Action list. The reasoning behind that is the nodes are very hard to decipher when zoomed out on the graph unless there are spaces between the names.

• Added UPARAM AllowedClasses and ShowDisplayNames metadata specifiers for UClass/TSubclassOf type parameters. These work like their UPROPERTY metadata specifier counterparts of the same name.

• Reroute nodes can now display compiler notes, warnings, and errors

• Added CreateBlueprintAssetWithParent editor function, for creating blueprint assets with a specific parent class

Bug Fix:

• Fixed potential for deadlock when terminating a global Find-in-Blueprint query in projects that may index references to StringTable assets.

• Fixed a crash when reloading a blueprint when the diff window is open

• Edits to sparse class data now propagate properly to child classes

• Changing categories of macros in libraries does not update in search menu of other BPs When changing a macro category, we need to actively update the action database with the change. While SetBlueprintFunctionOrMacroCategory does call MarkBlueprintAsModified, this won't trigger the Blueprint's OnChanged callback, which the database normally relies on for changes.

• The Details Panel's "Create New Blueprint" button now works correctly with Soft Class Properties

• Searching for references to an event function via the My Blueprints context menu no longer inadvertantly double quotes the event name

• Fixed cause of errors being raised after reparenting a blueprint

• Removed long broken shortcut for creating an Array Get item at Index node in blueprints

• Fix ensure when trying to update 'object being debugged' and we were previously debugging an object that is no longer valid, but still exists

• Fix blueprint editor crash where creating a Soft Object reference to a Component or UserWidget would incorrectly show the inline subobject UI and crash when you tried to use it. You normally want to use Soft Class references to blueprintable assets like these.

• Fixed bug that would cause clicking an entry in the blueprint context menu to spawn the incorrect node

• The tooltip associated with the config variable checkbox in the blueprint editor no longer erroneously mentions SKEL_ classes

• Fix a potential race condition during Blueprint asset search data indexing.

• Editor Crash when adding components to a Editor Only BP Actor Iteration over child nodes didn't have sufficient safeguards for any entry removal. After calling FactoryCreateInheritedBpSubobject, we need to ensure that the iteration index is still within bounds.

Blueprint Runtime

Bug Fix:

• Fixed broken logic related to construction script deferral due to static mesh compilation

• Fixed crash when the BPVM calls SetArrayPropertyByName with a null object. Most of the functions in KismetArrayLibrary.h check for a null property address and set bArrayContextFailed to true, which induces a runtime failure. However, SetArrayPropertyByName was overlooked, and would cause a crash due to a null dereference.

• Optimized UUserDefinedStruct::InitializeStruct in non editor builds

Gameplay

API Change:

• UAbilitySystemComponent::InternalTryActivateAbilityFailureTags should be set correctly to both the failure reason and which tags caused that reason to happen.

• The big projects that use a lot of gameplay tags may want to limit the tags they use to identify gameplay ability events. Adding a gameplay tag filter allows such a project to use tag category remapping to adjust all filtering to their gameplay tag structure.

  • To enable this feature, use the Category Remapping settings to remap "GameplayEventTagsCategory" under "Project Settings / GameplayTags".

• C++ code stays the same in this case, but the DisplayNames are altered in Blueprints to help designers. Properly renaming the functions in C++ was out of scope.

• Some data that used to reside in FMoverDefaultSyncState, such as MovementMode and the Layered Moves Group, is now accessible through FMoverSyncState instead.

• Prefer to use the Gameplay Abilities Developer Settings class directly rather than AbilitySystemGlobals when querying settings variables. Prefer AbilitySystemGlobals for global override functions.

• Note: a NavMoverComponent will have to be added in addition to a MoverComponent to get pathfinding working properly. This was done in an effort to have some separation for nav specific data and functionality.

• Blackboard access should be through the movement component if needed.

• When querying for current abilities (such as through FindAbilitySpecFromHandle) there is an EConsiderPending to specify how to handle pending abilities (abilities about-to-be-added or removed).

• Deprecated FTickableObjectBase::IsAllowedToTick because it was slow and redundant with the existing IsTickable function. The new SetTickableTickType function is a more efficient and safer way to dynamically disable tick

• Previously, removing a GameplayCue would cause a single EGameplayTagEventType::AnyCountChange callback with its Tag and Count, even though all equivalent Cues would receive an OnRemove. So previously: 15 GC Tags would be a single callback and now it will be 15 callbacks. This will change behavior if you're using something like AbilityTask_WaitGameplayTagCountChanged on the GameplayCue Tag (that callback would fire 15x now, and just once previously).

  • The CVar to toggle this functionality is GameplayCue.Fix.UseEqualTagCountAndRemovalCallbacks (it is now defaulted to true)

• Through the discovery of this bug, it's been reasoned that it is never safe to ClearInvalidTags. Thus all functionality which allows one to do that has been deprecated and/or removed.

• The (Blueprint) GameplayTagInterface::GetOwnedGameplayTags member function has been redirected to BlueprintGameplayTagLibrary::GetOwnedGameplayTags. The implementation ensures that the results you get are always a newly initialized tag container, thus ensuring you do not accidentally reuse and append old results.

• GetLedgeMove() and CheckLedgeDirection() had their "GravDir" parameter removed (in favor of using the CharacterMovement gravity direction), while adding the previous valid floor as a param.

• This would have had very subtle bugs in the past, where a server-initiated prediction key would "catch-up" client keys, possibly before (or after) rejecting them. The new FPredictionKey handling makes these bugs more apparent.

• Otherwise, it's possible to leak FPredictionKeys as some could be generated and never acknowledged because the batch chooses only a single key to be sent (when it can be acknowledging as many as three different events). By making the keys dependent, just a single acknowledgement will acknowledge all of those events.

• p.NetServerMaxMoveDeltaTimeScalar adds a scalar on the server, clamped to >= 1

• GAS - UGameplayEffectComponent::OnGameplayEffectChanged has been changed to non-const to allow the proper flow of updating its values on Post Blueprint Compilation. This allows us to update the inheritance values on Blueprint compilation which will happen after serialization (which could stomp PostInitProperties values).

• As part of the performance improvements to world ticking, static level collections will no longer be created by default. These were only used by the disabled client world duplication feature (but they can be created by setting s.World.CreateStaticLevelCollection)

• This behavior can be disabled with the "Input.bAutoReconcilePressedEventsOnFirstRepeat" Cvar.

• In case this somehow causes issues unforeseen issues with split screen games, it can be disabled with the cvar 'input.bRemapDeviceIdForOffsetPlayerGamepadIds'.

New:

• GAS - When an ability is blocked by a tag, we should report which tag caused the block. Added a generic tag for when the native or blueprint CanActivateAbility function blocks activation.

• Mover: Adding BlueprintInternalUseOnly to LayeredMove, InstantEffect and MovmentModifier base structs to disallow making and queueing the base structs in BP. Also making error message for not implementing Clone function clearer and more helpful.

• Added a new GameplayTags function to move tags between ini files

• GAS - Adding GameplayTagFilter to API that works with gameplay tag events (see Programmer Notes)

• Mover: adding a stance movement modifier meant to handle different stance changes such as crouch #virtualized

• Added a new CharacterMovementComponent flag that allows jump logic to only apply jump velocity at the start of the jump, not continuously throughout the entire jump hold time, which remains the default behavior

• Deprecated old CharacterMovementComponent::DoJump and made it to call the new DoJump function, which now allows caller to pass in DeltaTime. Existing code will continue to call the old DoJump, and the new behavior can be opted into via a cvar.

• Add IsDataValid to FTableRowBase which can be used to enable data validation for data tables

• Mover: changed montage-based anim root motion behavior to end itself once the mesh is no longer playing the montage, allowing smooth transition back to controlled movement without loss of momentum

• Mover 2.0 adding Flying gameplay tag and adding some state checking functions to CharacterMoverComponent

• GAS - Gameplay Cue Notify Actor (Looping) Function names have been renamed to give users a better understanding of when they trigger. An asset validation warning has been added in the case where a user implements OnActive and OnRemove, but not WhileActive. These have now been named to OnBurst, OnCeaseRelevant, and OnBecomeRelevant respectively.

• Mover: stood up initial version of a standalone backend liaison for non-networked games

• Trace Targeting Selection / Engineering: Added option to use Single trace instead of Multi trace. This allows for ensuring only one hit result is given, avoiding the case where an initial overlap hit is given along with the first hit past the initial overlap.

• Mover 2.0: Adding Movement Modifier system - a system that is used to apply changes that indirectly influence the movement simulation, without proposing or executing any movement, but still in sync with the sim.

• Added optional acceleration to RepMovement, in support of allowing Characters replicating it to sim proxies.

• Mover 2.0 removing OnImpact delegate since as it was unneeded and could potentially affect performance

• Mover: Adding ProcessGeneratedMovement delegate for mode-agnostic modification of proposed movement after it has been generated.

• Disable concurrent actor/component tick queuing by default as it is slower in most cases and also causes reliability issues, it can be re-enabled with tick.AllowConcurrentTickQueue. This was disabled in code on platforms like windows, but now all platforms work the same by default

• Mover: Adding Instant Movement Effects. A new Mover system that allows for direct modification of sync state for one frame. This essentially replaces any instantaneous layered moves like teleport or launch.

• Mover: Converting Movement modes to use new instant movement effects for jumping and teleporting. This change also moves jumping out to the character movement component rather than specific modes (Modes can still handle jumps specifically if desired)

• Mover: adding velocity to the mover debugger

• GAS - Add OnMontageBlendedIn support for PlayMontageAndWait ability task

• Mover: added data validation and runtime checks for transitions

• GAS - Introducing FScopedDiscardPredictions which will allow users to write code that assumes predictions happen or not. For instance, cases where we want to the Ability System Component to do things that are unreliable / optional and this allows us to do that safely.

• Mover: adding API for directly reading/writing to the simulation sync state that is yet to be committed/sent. This is to help support advanced mechanics that may break out of Network Prediction's rigid simulation window in order to interoperate with other gameplay or physics-simulated objects.

• GAS - Adding Debug support for GameplayAbilityTargetActor_Radius

• Mover Examples: Renaming Dashing pawn to AnimatedMannyPawnExtended and moving it out of the variants folder to the pawns folder #virtualized

• Mover: Removing teleport layered move as it's functionality now lives in the teleport instant movement effect. This allows us to get rid of some data in FProposedMove.

• Mover Examples: Adjusting example content to use instant effects where appropriate and adding a instant effect map #virtualized

• Mover: removed unnecessary base pawn class

• Mover Examples: Fleshing out dashing/extended pawn to have animations for all of its extra functionality including, Flying, Multi-jump, Ziplining and Dashing. This also splits off a separate animation blueprint for the extended examples pawn that contains functionality for all of these animations. #virtualized

• Added a new flag to Targeting Sort Tasks that preserves the relative ordering of targets with equal scores, at the cost of slightly worse performance.

• Mover: added templated convenience function to access the typed MoverComponent from the movement mode

• Physics Mover - Add networked input struct for max speed and acceleration to avoid desyncs when changing these dynamically

• Mover - Support multiple settings classes

• Mover: Adding NavWalkingMode to support more efficient walking movement for actors using a navmesh

• Mover Tests: Adjusting automated test plugins and adding automated test map for instant movement effects

• Mover: moved required properties out of the sync state collection and onto the core sync state

• Mover: added optional data validation for backend liaison classes

• GAS - When Clearing an FScalableFloat Property field (using the UI), the RowName doesn't get reset. This can cause warnings/errors later when the scalable float is being evaluated because it has a RowName but no CurveTable.

• Mover: added BP-callable function to manually set primary visual component

• Mover: Added a bool to Falling Mode to customize landing - actors can now land and cancel vertical velocity or have the vertical velocity redirected based off the surface they landed on.

• Mover: Adding gameplay tag query functions to support querying gameplay tags across different mover systems

• GAS - Gameplay Debugger now reconciles Server vs. Client state for Gameplay Effects, similar to how Tags and Attributes work. Recolored the Gameplay Debugger to prefer Yellow (the common color) for properly networked attributes/effects. Aligned some text better. Small refactor for the Attributes.

• Mover: improved data validation to prevent a variety of bad setup issues

• Mover - Add gameplay tags to movement modes to indicate state

• Mover: added planar movement constraints which are respected in the default character movement modes

• Physics Mover - Support non-async physics update

• GAS - PGameplay Abilities Developer Settings. Introducing the option to configure the AbilitySystemGlobals through an easier to understand user interface found in the Editor's Project Settings. Backwards compatibility is maintained with the old data.

• Optimize UGameplayTagsManager::GameplayTagsMatchDepth to remove excess allocations.

• Added a way to temporarily override how the GameplayTagsManager handles unloading of GameplayTags.

• GAS - Add On GameplayEffect Inhibition Changed delegate

• Added a way to temporarily defer rebuilds of the GameplayTag tree managed by the GameplayTagsManager.

• Mover: export common movement mode gameplay tags, so external modules can use them directly

• Add UWorld::EndPlay which properly calls RouteEndPlay and change the existing world shutdown code to use the new function. This must be called for any worlds that have a game mode and actually started play. Add a FTestWorldWrapper struct (used by new test System.Engine.Tick.PerfTest) which handles all of the logic required to create and destroy a gameplay world for automated tests. Fix several other issues with creating and destroying worlds during automated tests and improve warnings when things are done incorrectly.

• Mover: Adding a Movement Mixer class that helps mixing layered moves and proposed moves and makes it more extensible.

• Mover - Add mode activate and deactivate functions

• Mover: Added more debug info to the Gameplay Debugger Tool readout

• Mover: Layered move preferred moves only set the mode the first time they tick to avoid a mover system constantly setting movement mode

• Mover plugin: added support for Mover trajectory prediction for use with motion-matching animation tech in PoseSearch

• GAS - Exposing Gameplay Effect's GetAssetTags / GetGrantedTags to Blueprints

• GAS - Exposing Gameplay Ability IsActive to Blueprints.

• Mover: expanded transitions supported so they can always be actively evaluated, no longer limited to individual modes

• Added public native function for setting the user description of a FGameplayTagQuery

• Adjusting some comments in NetworkPredictionConfig so options in projects settings have correct/helpful tooltips

• GAS - Changed the friendly DisplayNames of the GameplayEffectComponents to make them easier to comprehend.

• MoverExamples: added ziplining mechanic example

• GAS - Adding "ShowDebug AbilitySystem" to the console auto-complete list

• GAS - Create GetExplicitTagCoung util for FGameplayTagCountContainer

• GAS - Optional parameter to GameplayTagCountContainer::Reset allows a user to empty the container while keeping all of the registered tag count change callbacks.

• Add GetPossibleDataRegistryIdList to the DataRegistrySubsystem to allow iterating registries from blueprint. Deprecate GetCachedItemFromLookupBP in favor of new "Find Data Registry Item From Lookup" that uses multiple output pins. Clean up the comments and names of the BP functions to remove experimental tag.

• Targeting System / Sort By Distance: Added option for more accurate distance calculation based off of nearest collision surface instead of actor location.

• Mover: Adding functions to allow users to poll mover component for active layered moves by type.

• Add a new Tick Batching system for actors and components which can be enabled by setting the tick.AllowBatchedTicks cvar. When enabled, this will group together the execution of similar actor and component ticks which improves game thread performance. Also added options like ForEachNestedTick to TickFunction to better support manual tick batching (which can be faster than the new automated batching)

• [GAS] Adding some debug information to track down warnings for potentially invalid use of GetOwnedGameplayTags() and related functions on Gameplay Effects.

• [CharacterMovementComponent] Option to base the character on the attachment root of the object that the character is standing on. UCharacterMovementComponent::bBaseOnAttachmentRoot.

• Mover: added initial support for taking root motion from a mesh attribute

• [GAS] Added invalid data warning when BlockAbilityTags is used with Instant GE

• GAS - Improving the GAS Debug Facilities. Attributes can now be debugged in the Gameplay Debugger. Layout of the GameplayDebugger is better formatted.

• Mover: Adding Pathfollowing and NavMovement support. Also adding some example content to show/test the feature. #virtualized

• [GAS] Giving a warning to users during validation that an FScalableFloat RowName could be invisibly set to a value (which would cause warnings at cook/runtime).

• GAS - Adding meta=(DeterminesOutputType) to GetAttributeSet of AbilitySystemComponent

• GAS - Adding the Gameplay Ability System README.md. We accept pull requests for better documentation!

• Added new CVars that allow CSV Tracking for the following Movement related stats:

  • CVar: p.ClientRecordMovePackedRpcStatsToCsv

  • CVar: p.ClientRecordNetCorrectionDistanceToCsv

  • Correction Distance: whether the client received a correction from the server and how big it was.

  • Num movement RPCs the client sends to the server per frame

  • Num movement RPCs the client receives from the server per frame

  • Size of the sent Movement RPCs

  • Size of the received Movement RPCs

  These stats will be recorded to the new CharacterMovementDetailed CSV Category

• Mover: Removing movement mode GetBlackboard functions.

• GAS - Introduce LogGameplayCues category which initially shows nothing, unless you set it to Verbose.

• Mover Tets: Updating LayeredMove Automated test map to reflect new layered moves #virtualized

• SplineComponent::GetSplinePointAt() now returns full FSplinePoint data. Previously it was missing the spline's Type property.

• Fixes CharacterMovementComponent applying an anim montage's root motion with incorrect scale on last tick when the montage is triggered by AbilityTask_PlayMontageAndWait and the skel mesh is not recently rendered.

• Fire the OnInputHardwareDeviceChanged event whenever the hardware device id changes from the last known platform user id map, not the input device id map. This gives us the desired behavior of firing a delegate any time the Platform User changes their "most recently used" input device, instead of only ever firing when an input device is connected.

• Add a Kismet Math library function to access the value of a FRuntimeFloatCurve.

• Mover: updated readme based on recent development

Bug Fix:

• Fixing APlayerController::PostProcessWorldToScreen() not applying to ProjectWorldLocationToScreenWithDistance() #9917

• GAS - Fixes for issues where Gameplay Effects & PredictionKeys. Solidifying rules around the client/server communication. It includes:

  1. GE's could be without communicating a prediction key if it went through SendGameplayEventToActor.

  2. GE's could be removed without being the authority through certain paths.

  3. Server Initiated PredictionKeys were being sent down to the client, but it takes a spot in a circular buffer and thus it's possible it stomps an actual client FPredictionKey.

  4. Extra logging and ensures to clarify these rules.

  5. Changes to the Abilities Gameplay Debugger to catch these issues (previously multiple applications of a GE could go undetected).

  6. Blueprint function MakeSpecHandle has been deprecated in favor of MakeSpecHandleByClass since you need the CDO instance.

• Network Prediction plugin: fixed issue where client and server would desync on the number of inputs shared, causing ensures and continuous reconciliations

• Mover: fixed crash that could occur for Mover actor instances outside of a game world, such as an in-editor thumbnail renderer

• Mover: fixed bug where a layered move could work with old state data if sim tick is split into multiple substeps

• GAS - Use CurrentValue instead of BaseValue when dispatching AttributeChangeDelegates in replication case. This solves a case where you can listen for the AttributeValueChangeDelegate on a Simulated Proxy and receive the Base value rather than properly aggregated value.

• Fixed inconsistency between how FInputAxisBinding and FInputAxisKeyBinding determine their axis value when the input key has been previously consumed

• Mover: fixed issue with inconsistency in auto-finding a primary visual component between cooked and non-cooked assets.

• Fixed issue where a Character sliding down an unwalkable surface get hung up without sliding all the way down to a walkable surface

• GAS ActivationOwnedTags now correctly replicate the tags to clients just once (not twice like previously).

• MoverExamples: fixed bug where users could attempt to instantiate a MoverExamplesCharacter, which is intended as an abstract type

• GAS - Added context menu to Gameplay Attribute widget (Editor)

• Mover: Fixing timing issue with layered move preferred mode not getting applied

• GAS - Fix for UGameplayAbility::GetSourceObject not returning a valid object when it is in the pending list.

• MoverExamples: fixed shadow rendering artifact issues on various pawn assets

• GAS - Properly dirtying the ActiveGampelayEffects array when granting a new Gameplay Ability Spec Handle. Adding some visual logging to help track down these complex issues.

• Fix several crashes when trying to tick partially destroyed world objects. TickableWorldSubsystem and other world objects that use FTickableGameObject now disable their tick by calling the new function SetTickableTickType during unregistration. This uses a new SetTickableTickType function that can dynamically enable or disable ticking

• GAS - Gameplay Cue Notify Actors are now removed properly on Listen Server instances. Previously when Gameplay Effects were removed, the Gameplay Cue Tags would still be present on the listen server. AbilitySystem.GameplayCueNotifyTagCheckOnRemove would then refuse to issue the Gameplay Cue Removal event since that Tag was still present. The removal code has been rewritten to account for this.

• UCharacterMovementComponent::RoundAcceleration() changed to match the same rounding and clamping that is used by replication of FVector_NetQuantize10.

• GAS - Removing PackageMap assumptions from the Gameplay Debugger (it's not valid in Replay and could therefore crash when using during Replay)

• Fix bug where gameplay tags used in plugin config files would be lost if plugins were loaded in a different order

• Fix crashes when modifying the types of currently registered DataRegistry assets

• Mover: fixing issue with layered move mixing and preferred movement modes where Override velocity mix mode would override Preferred mode from OverrideAll

• CharacterMovementComponent: fixed cases where mid-tick changes in movement mode could continue movement with the old mode's Phys function. This could occur in a customized project when root motion causes lift-off into a mode other than MOVE_Falling.

• GAS - Console Command "AbilitySystem.Effect.Apply" return value has been fixed to account for Instant Effects.

• Mover: Fixing issue with control rotation pitch and walking/falling mode causing actor to stop moving

• GAS - Gameplay Effects could previously hold on to old GameplayTags.

• Fixed root motion replication to proxies when finishing root motion to ensure the replicated shadowed state is correct on the frame that root motion finishes.

• GAS - Fixing up some user-facing descriptions of FInheritableTagContainer.

• GAS - Fixed bugs caused by gameplay cue getting removed after OnRemove is sent to the cue

• Made FSoftObjectPath::LoadAsync const

• Fixed issue where readme files for Mover and Network Prediction plugins were excluded from distributed builds

• GAS - Reference to GameplayTag wasn't resolved correctly if the blueprint is loaded before the GameplayTag is registered. This could happen if a Blueprint is loaded early which contains a Native Gameplay Tag, but that Native Gameplay Tag is in a different plug-in.

• Mover tests: Removing some old unused mannequin assets and modifying some of animations used to remove some unused notifies #virtualized

• Mover: Initializing mover component start state on initialize and updating starting sync state on begin play if location has changed to avoid a warning about desynced positions. Also, downgrading an ensure to a warning to avoid pausing the editor for an issue that could potentially fix itself

• When Undoing Apply Instance Changes into a Blueprint class the actor instance now gets replaced with a new/updated version of the BP class that was updated. Fixes an issue with transaction buffer losing reference to the actor and deleting it.

• Mover: fixed bug where a turning rate that was a multiple of 360 degrees/second could prevent rotation in the default character movement modes

• Fixed a few different crashes that were a result of a replicated LevelSequenceActor being recreated on client, but using a SequencePlayer from a previous, destroyed copy of that actor that hadn't been garbage-collected yet.

• Mover: Fixing issue where falling mode wouldn't respect terminal velocity and apply gravity after clamping to terminal velocity

• GAS - GetOwnedGameplayTags Fix For Reusing old tag container in blueprint event graphs.

• Enhanced Input: Fixing issue with combo triggers not firing completed event when first and last combo action are the same action

• Fixing reinstancing issue with nested subobjects and transaction buffer not collecting all subobject info

• Mover: Fixing mixing issue where cumulative move didn't get correct mixing mode from mixing layered moves

• Mover: fixed crash that could occur in standalone games where an invalid scene component could be discovered during initialization

• GAS - GameplayCues: OriginalTag is never set for GCNs.

• Set DEFAULT_ORTHOZOOM for Paper2D editor viewports.

• GAS - Fix FGameplayEffectQuery::IsEmpty incorrectly returning true even if a CustomDelegate is bound

• Network Prediction: fixed issue where the FixedTickFrameRate setting was not respected for non-physics simulations

• Improved CharacterMovementComponent ledge movement functionality. Fixed deflection attempt reapplying acceleration, often making it fail by moving off the ledge again. Now GetLedgeMove() attempts to compute the ledge normal based on the hit of the capsule with the previous valid floor, and deflects movement as if hitting an invisible barrier.

• Mover: fixes issues with kinematic based movement latency and drifting

• Mover: Giving teleport layered move a higher default priority so it isn't overridden by other moves by default

• Mover Examples: Base pawn now has missing flying animation #virtualized

• Mover: Making multijump properly assign InAirJumps left so walking off platforms still allows the actor an in air jump

• Mover: Fixing issues with TimeStep being passed into different mover systems where SubTimeStep should have been used

• GAS - Ensure FPredictionKeys only attempt to "catch-up" if they were locally generated. If they are Server Initiated, then ignore them for catch-up purposes.

• Mover: GenerateMove for LayeredMoves in subStep loop should use SubstepStartData and SubTimeStep.

• Mover: Adding some data validation to physics movement modes to make sure that a physics backend class is present to avoid unwanted interactions and crashes

• GAS - Gameplay FPredictionKey Fixes. 1. Previously, when calling a CaughtUp or Rejected callback, the FPredictionKey Replication Array could realloc while you were holding on to the reference. 2. Introduced some debug functionality that will attempt to catch these extremely hard to find cases where an FPredictionKey could be created and never acknowledged. 3. Added CVars for controlling behavior on how FPredictionKey Dependency Chains should behave.

• Mover Examples: More polish for the Extended pawn. Adjusting aiming camera location, adding a dashing cooldown, fixing issue with vaulting playing flying animation after ending #virtualized

• Mover: Adding some safety measures to AddMovementMode to avoid issues with passing in abstract classes

• During actor reinstancing old actor components are now unregistered before spawning their replacements to avoid collision with component registration

• GAS - FScopedServerAbilityRPCBatcher should ensure all keys generated in its batch are dependent.

• GAS - AbilitiesGameplayEffectComponent could fail to grant and remove abilities if those abilities were granted/removed during the same scope lock (due to the PendingAdds/PendingRemoves). Making this more clear by allowing users to query the pending lists in some interfaces (EConsiderPending).

• Mover: fixed issue where root motion in async simulations could be greatly exaggerated

• Improved behavior to reduce character movement corrections by allowing server to run longer move time deltas than the client is allowed to send, to account for when client updates are lost or jittery and a longer time should be used. Fixed client timestamp when forcing updates, allowing client time advanced during normal updates, and stopping after duration limit exceeded.

• Only enable AspectRatioAxisConstraint on the camera component if it is actually going to do anything

• Change GameFeatureSubsystem::AddObserver to notify the new observer about any relevant plugins that are already enabled

• GAS - UGameplayEffectComponent::OnGameplayEffectChanged has been changed to non-const

• Several performance improvements to world ticking, especially when using world partition

• GAS - Skip the check for unmapped references when receiving the replicated Server Initiated Gameplay Effects. This ensures the Gameplay Cues will always fire properly.

• Fix crashes that could happen when modifying the GameFrameworkComponentManager delegates during execution of those delegates

• Mover: fixed issue with interpolating between states that had different movement bases, typically leading to unintentional teleportation

• GAS - FActiveGameplayEffectsContainer::CheckDuration will no longer remove Infinite Gameplay Effects.

• GAS - Handling a case where InstancedPerExecution abilities could ensure if being Removed while in an EndAbility callstack.

• GAS - Fix unbinding OnMontageBlendedInEnded delegate.

• Mover: fixed check crash when compiling a BP that has a MoverComponent with a NetworkPhysicsLiaison backend specified

• Cameras: fixed wrong error log message when stopping camera animations

• Mover: Fixing a crash that occurs when attempting to fire a Queue Layered Move that's connected to a non struct node

• Fix a bug where, if you are holding a key down during a level transition, the keystate map would incorrectly evaluate the state of the key as being released and re-pressed every frame. This meant that, for example, if you had a "Released" trigger on an Enhanced Input mapping context (or you were listening to any released event on a legacy mapping) that it would constantly fire as you hold down the key instead of only firing on release.

• Make the InputKey property on UK2Node_InputDebugKey Visible only, not editable. This fixes a bug where you could select the unsupported "Any Key" option from the key selector.

• Fix for bSkipAssigningGamepadToFirstPlayer in the GameViewportClient.

Deprecated:

• GAS - Make it clear that we currently do not support replication when using InstancedPerExecution GameplayAbilities.

• GAS - Deprecating FGameplayAbilitySpec::ActivationInfo since it only makes sense on NonInstanced Gameplay Abilities (which have also been deprecated). If you want that functionality, grab the instance and look at GetCurrentActivationInfo().

• GAS - Deprecating NonInstanced Gameplay Abilities. We now only support either InstancedPerActor or InstancedPerExecution. The motivation is to provide a more consistent interface of the UGameplayAbility functions.

Mass

API Change:

• MassRepresentation's functions using int32 InstanceId parameters have been deprecated. Use the FMassEntityHandle directly

New:

• Improved FMassExecutionContext's checks whether subsystems and fragments are bound and configured for read-write if accessing mutable version.

• fixed some processor execution flags to not run in pure Editor without associated world

• updated FMassArchetypeCompositionDescriptor::DebugOutputDescription to include shared fragments

• added new processor execution flags 'EditorWorld' and 'AllWorldModes' that could be used for processors that need to run when associated to a world in either client, server, standalone or Editor mode

• added function 'DetermineProcessorSupportedTickTypes' so processors executed in an Editor world can be ticked in all tick modes

• Added missing details about ConstSharedFragments in the archetype panel of the MassDebugger

• Added support for all owned queries for processors inheriting from UMassSignalProcessorBase

• Changed the Mass ISM-related API's usage of cryptic int32 to identify entities (usually obtained by hashing the entity handle) in favor of using the FMassEntityHandle directly. Added benefit is that we can directly identify the entity being processed by Mass Visualization, without additional lookups.

• Improved performance of merging Mass command buffers

• Changes to dynamic processor dependency solving to support dependencies between instances of the same processor class - for dynamic processors we use the processor instance name rather than class name while resolving dependencies.

Bug Fix:

• Changed how we hash ISMComponents in MassRepresentation Using object path can cause issues in WP worlds since levels being removed might get their name changed which changes the hash and causes issues when removing ISM shared data.

• Fixed broken Mass debug FAgentDebugVisualization wire shape visualization

• Running post spawn processors only is anything was actually spawned.

• Fixed observers getting notified before the fragments values are set on entities created through 'CreateEntity' and 'BuildEntity'

• Changes to make editor-available Mass processors actually execute in editor mode.

Networking

API Change:

• UNetConnection::GetConnectionId() is deprecated in favor of UNetConnection::GetConnectionHandle().

New:

• NetBitArray - Added safer ways to access internal buffers held by a FNetBitArray and FNetBitArrayView

  • GetWord() can be used to safely access the full 32bit value to modify 32bit entries at once.

  • GetDataChecked(NumWordSize) can be used to access the raw array buffer but will also validate that the maximum word iteration count is within the bounds of the NetBitArray

  • Reset() has been deprecated in favor of ClearAllBits()

• Networking: Added Networking_FastArray_Apply csv scope to FastArray reception codepath

  • Allows to track regressions in FastArray user code

  • Exposed CSV Networking category via NetCore module export

• NetDriver Added exclusive csv cpu scope to FlushNet call to track time spent inside NetworkHandlerComponent (compression, encryption, socket send, etc.)

• NetDriver Handshake - The NetDriver of client connections will now automatically change the ReplicationSystem from non-Iris to Iris (or vice-versa) when they receive an Upgrade control message with a NetworkRuntimeFeature incompatibility

  • Works in both the statelesshandshakecomponent and regular netconnection handshake

• NetDriver Allow GameInstance's to override the Iris ReplicationSystem config

• Change client pawn controller replication logic to properly call OnRep_Controller and NotifyControllerChanged when the controller is changed by code like ClientRestart that bypasses normal replication (this can be disabled with Controller.AlwaysNotifyClientOnControllerChange)

• NetTokens are now serialized using separate indices per NetTokenDataStore

• NetAnalytics

  • Added ability to add game specific attributes to the NetAnalytics framework

  • To add those game attributes, Implementations of FNetAnalyticsData must call AppendGameInstanceAttributes before calling SendAttributes.

  • Add or modify your game attributes with the NetDriver::SetNetAnalyticsAttributes function

  • NetDriver will add some default attributes (NetDriverName, NetDriverDefinition, ReplicationModel, NetMode) when net.AddNetDriverInfoToNetAnalytics is true

• Added http.CurlAllowHTTP2 CVar to enable HTTP/2 for platforms using libcurl (defaults to false)

• Added NetRefHandleManager as a protected member of NetObjectFilter for other internal filters to use and not having to create their own member.

• Added protected GetObjectIndex function to NetObjectFilter. It returns the object index for the given NetRefHandle.

• Added IRISCORE_API to UNetObjectGridWorldLocFilter, so that other game modules can derive from this class and extend it.

• Added CSV Profiling Stat tracking for Average Jitter (milliseconds)

• Added CSV Profiling Stat tracking for Packet Loss Percentage (In/Out)

• Added "net.DisableRandomNetUpdateDelay" CVar to toggle the random delay added to actors' NextUpdateTime.

• NetDriver

  • Added some functions to allow swapping a NetDriver from a ReplicationDriver (RepGraph) to a ReplicationSystem (Iris) without destroying and restarting the netdriver

• Experimental support for NetTokens to allow exporting stable pieces data such as strings and GameplayTags only once to reduce bandwidth usage. See NetTokenStore.h for details.

• Added CSV profiling markers to Oodle when processing incoming packets.

• Added CSV profiling markers to Oodle when processing outgoing packets.

• Implemented FConnectionHandle which carry both parent connection and child connection information. This can be useful for APIs where it's important to keep track of child connections as well.

• Added console command to set nettrace verbosity at runtime - NetTrace.SetTraceVerbosity [verbositylevel]

• Added UE::Net::FTestWorldInstance and UE::Net::FTestWorlds to enable writing synchronous test cases within the scope of one function that utilize full UWorlds and the whole networking & replication path. The worlds created are PIE worlds and only work in the editor.

• Added cvar net.SerializeNewActorOverrideLevel that can be optionally disabled to bring back the functionality of spawning replicated, dynamic actors in the persistent level on clients, regardless of its level on the server. This was the behavior in UE 4.19 and earlier.

• Enabled EWorldType::Game worlds to be dedicated servers if desired in the editor.

• Add a new UFUNCTION specifier "Remote" that turns the function into a unicast RPC that can be invoked on either clients or servers and executed on the remote side of the net connection. These functions will only execute remotely and only on net-owned actors.

• Added Iris replication support for UInstancedActorsData.

• Added a very early, experimental MultiServerReplication plugin that exposes a peer-to-peer like interface for communicating between multiple UE instances via online beacons. The only supported method of communication is via RPCs of subclasses of AMultiServerBeaconClient. Also added a UAT script LaunchMultiServer to automate launching a multi-server setup.

• Added limited support for dynamic, replicated actors moving between levels at runtime on servers (via changing outer with the Rename function):

  • It's recommended to spawn dynamic actors in the world's persistent level and keep them there instead of relying on this feature.

  • This does not automatically replicate the level change to clients! If using this feature, set the cvar net.SerializeNewActorOverrideLevel=0 to keep the actors in the persistent level on clients.

  • This does not support actors placed in maps or other net-addressable/stably-named actors.

  • Use with the cvar value net.CleanUpRenamedDynamicActors=1 to destroy the actors on clients if they move into a level the client doesn't have loaded.

  • If using ReplicationGraph, set the cvar net.RepGraph.HandleDynamicActorRename=1.

Bug Fix:

• Crash fix for removing InstancedStruct from a replicated array and adding the same struct type again when using Iris Replication.

• Iris - Fix for issue where replicated overridden blueprint events/functions would not call the overrriden event/function

• Iris - Fixed issue with changes to SubObjectFilterGroups would not enforce dirtiness until subobjects was modified

• Iris - Invalidate delta compression baselines for the entire object hierarchy if a condition change are affecting properties in sub objects too. Prior to this fix such condition changes could cause bitstream errors on the receiving end.

• Fix to ensure that members for both object and subobjects affected by changing conditionals such as owning connection, physics and role always are marked dirty when condition is re-enabled when using Iris Replication.

• Fixed compilation error when UE_NET_ENABLE_REPLICATIONREADER_LOG is enabled.

• Ensure locally controlled pawns on a listen server don't have a RemoteRole of ROLE_AutonomousProxy.

• Iris - Fixed bug where late joining clients could cause ensures when RPCs were called on sub objects of relevant to owner only and connection filtered actors.

• Iris - Keep reliability when splitting a NetBlob. Split unreliable multicast RPCs will now also keep their normal execution order.

• Fix NetConnection crash when receiving packets from an IP address that was previously remapped after the user's client connection was cleaned-up.

• Fix for ASAN crash issue on shutdown where UActorReplicationBridge would read from an already cleaned up reference to PackageMap. Changing to a UPROPERTY TObjectPtr fixes the issue. [RN] Fixed a case for a potential rare crash when shutting down ActorReplicationBridgebmittool SubmitTool-Development-4.2.0.1191505988

• Fixed bug causing packet simulation to potentially be applied more than once on the same packet.

• Fix for ASAN crash in Iris ObjectReplicationBridge - use cached version of FilterProfile instead of dereferencing a potentially invalid pointer due to array reallocation

• Fixed issue where UHT did not generate separate FastArraySerializer type for FastArraySerializer's derived from other FastArraySerializers resulting in overloaded methods being called on base type instead of most derived type.

• Fixed issue where some exports was not properly exported with recorded demo frame if exported by checkpoint causing bunch errors due to not all mustbemapped exports being registered.

• Fixed an issue with Iris replication where reliable RPCs sent right before a client is disconnected (via the server kicking them, for example) could be dropped, especially under packet loss.

• Fixed a bug with Iris replication where replicated components of an initially-dormant actor wouldn't replicate if the actor's dormancy is flushed before BeginPlay is called.

Learning Resources

Sample Content

New:

• Updating templates that weren't setting r.AllowStaticLighting to either False or True, to r.AllowStaticLighting=False

Level Design and Art Tools

Bug Fix:

• Fixed the level viewport tool bar having a wrong width with cinematic viewport.

Geometry Core

API Change:

• A new CVar, modeling.DisableAutoUVAreaDensitySampling, can be set to return the behavior to the original algorithm, in case there are legacy reasons to maintain that behavior.

New:

• Added a faster variant of the Orient2D exact predicate for the case where one point is at the origin.

• Generalized the GeometryCore grid interpolation code to support float as well as double precision, added support for clamping queries to the grid bounds, and fixed the Bounds() method to return the correct bounds.

• Added new methods to VectorUtil for uniform random sampling of positions and barycentric coordinates on triangles

• Improved the UV generation scheme PatchBuilder via a change to the polygroup generation stage, providing area aware sampling of the mesh surface and reducing the overcompensation effects that small, disconnected regions in the mesh were having on the overall segmentation.

Bug Fix:

• Fixed a case where Dynamic Mesh could create invalid geometry when merging an edge pair.

• Fixed crashes in the Convex Hull and Convex Decomposition methods.

• Fixed an issue where the local parameterization (exponential maps) algorithm generated incorrect results for meshes without vertex normals.

• GeometryProcessing Sparse Matrix: fix a crash when solving large sparse systems. We were computing NRows * NCols which can overflow int32 on moderately large matrices (~50k by 50k).

• Fixed an issue where mesh surface point sampling could hang on meshes with degenerate triangles.

• The Dynamic Mesh CompactInPlace method now compacts more of the internal mesh data, fixing an issue where Convex Decomposition and some other algorithms would use an excessive amount of memory when processing large inputs.

• Fixed an issue where the AABB tree build could crash for meshes with NaN or Inf vertices.

• Fixed crashes and improved behavior of the Bevel algorithm on meshes that have bowtie vertices.

• Update xatlas source files from github. Fixes a buffer overflow

• The FitKDOP3 method now by-default adds a small thickening to its convex hulls, allowing it to create valid convex hulls for flat shapes. This thickening is exposed as a new parameter.

Geometry Script

New:

• Added the option to set the material ID to use for hole fill triangles, for the plane cut and plane slice Geometry Script methods.

• Made Geometry Script's Compact Material ID method optionally also remove duplicate materials

• Moved Geometry Script out of 'Beta' status.

• Added a new node to geometry scripting, "Prune Bone Weights", to prune a set of bones from all skin weights. This is useful when creating alternative skin weight profiles where specific bones need to be deactivated.

• Added a new GenerateCollisionFromMesh method to Geometry Script, which fits simple collision primitives to an input dynamic mesh.

• Added a new volume texture baking method to Geometry Script, which bakes a mesh SDF to a volume texture -- BakeSignedDistanceToVolumeTexture

• The Geometry Script Add Primitive methods (Add Box, etc) now support requesting a material ID to be assigned to the appended mesh faces, via the FGeometryScriptPrimitiveOptions struct's Material ID member.

• Geometry Script now has a global dynamic mesh pool, created on first access, to make it easier to use mesh pools in utility widgets.

• Geometry Script's CopyMeshFromStaticMesh and CopyMeshToStaticMesh methods can now optionally use the 'asset' materials list rather than the 'per section' materials list, for cases where one would like the materials list not to vary per LOD and to match with the list the UI shows on the asset. Per section materials are still used by default. If you use the asset material list, be sure to specify this in both the 'copy from' and the 'copy to' calls.

• Added a new node, "Copy Bones From Skeleton", to copy the reference skeleton of a skeleton asset to a dynamic mesh.

• Added a new Geometry Script method to disconnect the mesh triangles along a selection of edges: ApplyMeshDisconnectFacesAlongEdges

• Improved the capsule generator to support a cylinder-section subdivision parameter, and to make UVs consistent across different subdivision / hemisphere step amounts.

• Geometry Script now has macros to automate the process of releasing meshes back to mesh pools after their use.

• Geometry Script now has VectorTransformInPlace, VectorInverseTransformInPlace, and VectorPlaneProjectInPlace methods to efficient transform or project all the vectors in a FGeometryScriptVectorList. The transform methods can optionally transform the vectors as positions (i.e., applying the translation component of the transform).

• Added new methods to manage simple collision shapes in geometry script -- CombineSimpleCollisionArray, to combine collision shapes from an array into a single FGeometryScriptSimpleCollision object, and ResetSimpleCollision to reset the shapes in a FGeometryScriptSimpleCollision object.

• Added a new Geometry Script node to remap material IDs and construct a combined materials list, to help with workflows where you need multiple meshes to have consistent material IDs

• The Geometry Script sweep functions now support "mitering" -- scaling the cross section at sharp turns to preserve apparent cross section width -- and have a Miter Limit parameter to control this scaling. (This is analogous to the stroke-miterlimit parameter in CSS.)

• Added 'With Collision' variants of Geometry Script's Append Box, Sphere, and Capsule methods, which return a simple collision shape matching the appended primitive.

• For meshes that are not the same, the IsSameMeshAs method now reports information about the difference it identified via a new FGeometryScriptMeshDifferenceInfo struct.

• Dynamic Mesh Component's ConfigureMaterialSet method now by default will remove extra material slots on the component, so can be used to reduce the number of materials on the component. The previous behavior can be requested by passing false to bDeleteExtraSlots.

• Added two new nodes, "Mesh Copy Bone Weights" and "Blend Bone Weights". The first one copies bone weights from one skin weight profile to another, which is useful when creating a new profile that is a simple modification to an existing profile. The second one allows blending two sets of bone weights into a single set, this is useful when implementing skin weight smoothing or proximity blending.

• Geometry Script now has new 'With Materials' versions of the various 'Append Mesh' methods. These methods take the materials array of the target and append meshes as input, and returns a new combined materials array that the resulting mesh materials IDs reference.

• Added bHaveValidUVs output param to GetAllUVSeamEdges.

• Geometry Script has new methods to help specify Constrained Edges for the AppendDelaunayTriangulation2D node -- CreateConstrainedEdgesLoop and CreateConstrainedEdgesChain.

• Added control over whether a Dynamic Mesh Component allows mesh element selection, which can be toggled via the SetAllowsGeometrySelection method. Generated Dynamic Mesh Components now default to disallowing this selection, since they will typically destroy manual selections and manual edits when they are re-generated.

• Added a new SnapMeshOpenBoundaries method to Geometry Script, which attempts to match and snap together nearby mesh boundaries without adding or merging any vertices.

• Dynamic Mesh Components now can optionally use the static render path, which can allow faster rendering (when mesh is not changing) and is necessary for Lumen support.

• Added new methods to get static mesh and skeletal mesh asset materials with corresponding material slot names, and also added new methods to convert from this array-based format to the material map format used by the Create New Skeletal Mesh method.

• Added a new geometry scripting node, "Copy Skin Weight Profile To Skeletal Mesh", that allows taking a skin weight profile from a dynamic mesh and applying it directly on a skeletal mesh asset, as long as the two mesh's topologies are identical.

• Added a new UVShell bake type to the BakeTexture GeometryScript node.

• There is a new Geometry Script method to set a custom complex collision mesh for a static mesh -- SetStaticMeshCustomComplexCollision

• Added initial Lumen support for Dynamic Mesh Component

• Added LineSetComponent as a blueprint spawnable component.

• Added new methods to select mesh elements by material ID and by polygroup -- SelectMeshElementsByMaterialID and SelectMeshElementsByPolygroup.

• Added more UV stats methods to Geometry Script: "Get Mesh UV Area" and "Get Num UV Islands"

• Added a GetLODMaterialListFromSkeletalMesh method, to get the materials list used by a specific LOD of a skeletal mesh.

• Added support for beveling meshes along a selection of edges in Geometry Script.

• Added new Geometry Script methods to select mesh boundary edges, selection boundary edges, and 'sharp' edges (with large dihedral angles) -- SelectMeshBoundaryEdges, electSelectionBoundaryEdges and SelectMeshSharpEdges respectively.

• Exposed GetAllUVSeamEdges and GetAllVertexPositionsAtEdges to MeshQueryFunctions.

• Added a "navigable convex decomposition" method to geometry script collision functions

• Geometry scripting nodes will now include the name of the calling Blueprint function when emitting warnings and errors. This makes it easier to track down the source of the message in large geometry graphs.

• Added a new Geometry Script method to set or remove sharp normals on edge selections: SetSplitNormalsAlongSelectedEdges

• Dynamic Mesh Component's physics mesh now supports querying UVs from hits, when the 'SupportUVFromHitResults' physics setting is enabled

• Added edge selection support to Geometry Script.

• Added a new Geometry Scirpt method to insert or remove UV seams along a selection of edges: SetUVSeamsAlongSelectedEdges

• Added a new UV layout function which exposes functionality from the UV Editor Layout Tool, including multiple layout types and restrictions on scale and rotation, to geometry script.

• Added new function to perform texel density UV scaling operations, allowing mesh UV islands to be scaled to match a consistent texel density over the whole mesh.

Bug Fix:

• Fixed an issue where the Mesh to Collision fitting algorithm would fit an incorrectly-rotated oriented box in some cases.

• Fixed an issue where CreateStaticMeshAsset would not set materials correctly when creating a static mesh with unnamed material slots.

• Fixed an issue where some Geometry Script nodes required options struct pins to be connected.

• Fixed an issue where bone data would be lost on dynamic meshes when they were serialized, causing some animation-related functionality to break in PIE or on load.

• Fixed a crash in GetMaterialIDsOfTriangles if passed null triangle list, and changed the behavior when passed invalid triangle IDs to match that specified by the docstring comment -- a material ID of -1 is set for invalid triangles, while correct material IDs are still reported for valid triangles.

• Added cvar geometry.DynamicMesh.MaxComplexCollisionTriCount to prevent Dynamic Mesh Components with many triangles from auto-generating complex collision, and fixed some issues with the collision preview rendering.

• Fixed an issue where duplicate points could be added when using error-based sampling of splines with 'constant' control points.

• Fixed issue where mesh surface point sampling would compute incorrect/inconsistent samplings for non-compact meshes

• Fixed an issue when using "Copy Mesh To Skeletal Mesh" and the source dynamic mesh did not have the identical skeletal structure as the target skeletal mesh asset. Now the bone indices are properly remapped on the skin weights so that they match the target skeletal mesh.

• Fixed an issue where 2D Voronoi diagrams would not be generated when the input points were collinear.

• Added missing null checks for Geometry Script Scene Utility Functions on UDynamicMesh* inputs

• Fixed issues in Geometry Script handling empty polygons and polygon lists -- AddPolygonVertex, AppendPolygonList not adding/appending, and AddPolygonToList crashing

• Added a missing null check to the StaticMeshHasCustomizedCollision Geometry Script method

• Mesh Transform methods now consistently transform normals and tangents.

• Geometry Script options structs now more consistently expose members as editable, when they are blueprint read/writable, so that they can be edited via the properties panel when used as variables.

• Fixed the AppendMesh nodes inconsistently handling transforms with negative scales.

• Fixed the Geometry Script "Set Simple Collision on Static Mesh" function crashing when run with a null static mesh.

Modeling Tools

API Change:

• Previously BrushAdjusterInputBehavior was used to set a toggle that would be read during the On*Drag callbacks to differentiate between a "brush stroke" and a "brush adjustment". This was error prone for both new and old tools that derived off of BaseBrushTool as it broke or was easy to break assumptions made in the tool's drag callbacks. With this separation, OnBeginDrag/OnUpdateDrag/OnEndDrag will only be called for brush strokes as it was prior to the introduction of the BrushAdjusterInputBehavior.

New:

• Added a 'cut outside' option to the PolyCut tool

• The Weld Tool can now optionally split bowtie vertices, which enables it to successfully weld edges in more cases.

• Modeling mode element selections now auto-convert selections when users change the active selection mode

• The Edit Triangles tool can now collapse seam edges

• There is a new option to toggle off the Cube Grid tool's grid plane visualization

• The edit pivot tool now uses the mesh element selection (if available) as an initial pivot point.

• New: Updated the default colors used in Mesh Element Selection. These colors can be customized in Edit >> Editor Preferences >> Plugins >> Modeling Mode >> Mesh Element Selection Mode

• Added a configurable NormalSpace property to BentNormal bakes to support object space BentNormal bakes in the BakeTexture tool and GeometryScript node.

• The draw polygon, draw polypath, and draw-and-revolve tools now initialize with a 'reasonable' drawing frame instead of starting at the origin. The frame is now center on the selection (if available) or the center of the view. If a mesh element is selected, the frame will also align to it.

• The Mesh to Collision tool has improved handling of convex decomposition: - Convex decomposition is now a separate option from generating single convex hulls as a separate shape type (rather than hiding the feature under the 'max hulls' count) - There is a new pre-simplify option to make the decomposition compute faster for very large meshes - The tool is set to use better defaults for the navigable space protection algorithm - The tool does not default-enable the 'max count' collision shape option, as it can be confusing/frustrating to wait for a decomposition only to find it has random holes due to that option quietly throwing away shapes

• The Transform tool now works on most component types, not just standard mesh types.

• Enabled tablet support with pressure sensitivity for Modeling mode.

• New: Added a 'Local Frame Mode' toggle in the Mesh Element Selection Toolbar Settings. Users can now use the gizmo to transform and edit a mesh based either on the selected geometry only or on the entire object.

• Add an "Add Capsule" tool

• Improved the "Split" tool to preview how it will split the mesh, and to give more options for splitting methods -- one can now split by mesh topology, vertex overlap (with a distance tolerance), material ID, or polygroup. Note if there is an active element selection, the tool will continue to split by the selection.

• New: Added support for Mesh Element Selection in the Lattice Tool. By using Mesh Element Selection to select components of a mesh and entering the Lattice Tool, only the selected areas of the mesh will be affected.

• New: Added support for Mesh Element Selection in the Split Tool. By using Mesh Element Selection to select components of a mesh and entering the Split Tool, only the selected areas of the mesh will be affected.

• The Mesh Splines tool now has the same material and output type settings as the Revolve Spline tool.

• Change some primitive creation tools to default to PerQuad, and make LatLong sphere PerFace not be the same as PerShape (and be same as PerQuad).

• New: Added new settings to the UV Editor's 'Display' menu. These allow customization of the Boundary Line Thickness, Boundary Line Color, and Wireframe Thickness in the Unwrapped Viewport, along with the Selection Line Color, Line Thickness, and Point Size in the Live Preview Viewport.

• Added a new UVShell bake type to the BakeTexture tool.

• Added DoubleClickBehavior to the ScriptableModularBehaviorTool.

• Add ability for CubeGrid to accept and start a new mesh without having to exit.

• Display selection measurements in CubeGrid in the viewport.

• Add tooltip for the status bar at the bottom of the edtior so it can be fully read.

• Rename Absolute Grid Snapping option in the gizmo settings in modeling mode.

• When the Cube Grid tool is started with an active Mesh Element Selection, the selection position is used as the origin of the grid.

• In the Edit Pivot tool, the snap-dragging feature has a new option to snap just the orientation of the pivot.

• The Vox Wrap tool now has an Apply Thicken Shells toggle and Thicken Shells slider, which can be used to capture open-boundary surfaces as shells of the specified thickness.

• Make the Weld action in PolyEdit weld to center, and add a "Weld To" action for the previous welding behavior.

• Added SkeletalMesh support for the Inspect tool.

• New: Added support for converting a selection when changing between mesh element and/or topology types in Mesh Element Selection

• New: Added a 'Snapshot' Tool in the UV Editor. This allows users to easily export a texture asset of a UV Layout, and to customize the look and resolution of the image to be exported.

• New: Added support for Mesh Element Selection in the Smooth Tool. By using Mesh Element Selection to select components of a mesh and entering the Smooth Tool, only the selected areas of the mesh will be affected.

• New: Added support for Mesh Element Selection in the Weld Tool. By using Mesh Element Selection to select components of a mesh and entering the Weld Tool, only the selected areas of the mesh will be affected.

• New: Added support for Mesh Element Selection in the Displace Tool when using the 'Flat' subdivision type. By using Mesh Element Selection to select components of a mesh, entering the Split Tool, and ensuring the subdivision type is set to 'Flat', only the selected areas of the mesh will be affected.

• Moved SDraggableBox slate widget into a new ModelingUI module, allowing it's usage in non-Editor Only contexts.

Bug Fix:

• Bug Fix: Updated the behavior when deleting PolyGroup Edges in Mesh Element Selection. Now, upon PolyEdge deletion, the edge's adjoining groups are merged. This behavior now matches the PolyEdge deletion functionality found in the PolyGroup Edit Tool.

• Fixed an issue where edge selections could be lost on tool accept after using the polygroup edit or triangle edit tools.

• Bug Fix: Addressed a bug where the Level Editor scale snapping affected the UV Editor scale snapping

• MeshModelingToolset: Update preview when toggling Shells to Solids in PolyEdit extrude activity.

• Bug Fix: Fixed a bug in in the LOD Manager Tool when using the 'Clean Materials' feature. Previously on input meshes with multiple materials, 'Clean Materials' would remove the incorrect material.

• Fixed the Select.InsertEdgeLoops tool initializing to the incorrect topology type. Prevent InsertEdgeLoops, InsertEdges and SimplifyByGroups tools from initializing in Triangle selection mode.

• Fixed an issue where some primitives could be generated off-center when created with very low polygon counts.

• Modeling tools now limit the number of background tasks that they will run simultaneously when generating preview results, especially for larger input meshes.

• MeshModelingToolset: Add Bridge action to TriEdit

• Bug Fix: Fixed a bug which did not allow for snapping when scaling a mesh in the XForm->Transform Tool

• Fixed an issue where group colors were not rendering correctly in Simplify and Remesh tools.

• MeshModelingToolset: Allow snapping to objects in scene when using DrawPolygonTool even when the camera is positioned such that the raycast does not hit the tool plane.

• Fixed an issue with brush resizing sensitivity in the InteractiveToolsFramework BaseBrushTool when bSpecifyRadius is false.

• Fixed an issue where some modeling mode selection operations would not work correctly for triangle edge selections.

• Bug Fix: Improved the 'Brush Size' setting in the Group Paint Tool so that when manually adjusting the value, the new size is now reflected in viewport immediately, without having to first click in viewport to see the update.

• Fixed material assignments being changed by the modeling tools for some assets.

• Fixed redundant UV mesh spatial computation in modeling mode bake tools.

• The Simplify tool's will now respect the prevent normal flips flag, and not prevent normal flips when that flag is disabled.

• Fixed a crash that could occur in the Draw Spline tool when using a blueprint that deletes itself.

• Fixed an issue where focus in some modeling tools did not work when there was no editor-level selection.

• Fixed crash by preventing use of the Convert tool on cooked-for-editor geometry collections

• The Polygroup Edit and Triangle Edit tools now auto-convert mode-level mesh element selections of mismatched topology type, rather than discarding them. Polygroup edge selections are now also properly converted, including in the case where the tool has enabled extra corner support.

• Bug Fix: Fixed a bug in the UV Editor's Seam Tool which displayed incorrect seam placement in some cases involving multiple selected meshes or rotation.

• Fixed an issue where box and cylinder UV projections could introduce new bowties in the UV mapping.

• Fixed polygroup colors not rendering in the subdivide, tri select, and materials tools

• Bug Fix: Fixed a bug that ignored scale transforms when creating new objects using mirroring.

• MeshModelingToolset: Fix crash when hiding actors deleted by tools with Delete Inputs option.

• Fixed Tri Select tool being called Triangle Edit in the Select tool group, so it has a consistent name and is not confused for the Triangle Edit tool in the Mesh tool group

• Bug Fix: Addressed a bug which caused undo and redo to not behave as expected or crash when deselecting edges in Mesh Element Selection

• Bug Fix: Disallowed Ctrl+Alt+Drag select when a tool is active which caused conflicting visuals relating to the active selection

• Fixed a crash when using the brush resizing hotkey (b) in Modeling mode sculpt and paint tools.

• Fixed a crash in the modeling mode's mesh element selection system that could occur when a mesh with an active element selection was deleted.

• MeshModelingToolsetExp: Replace various usages of Tan(0.5 * FOV) with new material function MF_OthoWidth

• We now prevent modeling tools from enabling element selection on non-editable dynamic meshes.

• Fixed a crash in MeshMapBaker.ComputeUVCharts when operating on non-compact DynamicMesh inputs.

• Fixed an issue where the Edit Normals tool could fail to correspondingly update tangents as needed in some cases.

• Modeling mode now warns users when selection includes engine assets, which cannot be modified

• Fixed an issue with modeling mode's mesh element selection where the gizmo could disappear after selection type changes.

• Raised the default limit at which we use a faster-but-less-reliable copy-paste method for dynamic meshes from 1000 triangles to 200,000 triangles, and added an editor toast to surface when the less-reliable method fails (and what can be done about it).

• PolyEdit's Bevel tool now refuses to start when there are no bevel-able edges in the current selection, and better handles selections with some boundary edges.

• Bug Fix: Fixed a crash that occurred when exiting the editor while Mesh Element Selection was active

• Fixed an issue where brush resizing using the hotkey (b) would not work when bSpecifyRadius was false.

• The Mesh to Collision tool now supports referencing custom PolyGroup layers when multiple inputs are selected.

• The Rotation setting in various Add Primitive (Add Box, etc) tools is now named Initial Rotation and is disabled when it is not applicable.

• Changed flyout dialog in the New Preset window to use a list presentation instead of a tile presentation, allowing for more clarity in reading names on long preset collection labels.

Deprecated:

• Changed the default target requirements for most modeling tools and tool builders to use UDynamicMeshProvider/Committer. Only specific tools that directly get the MeshDescription in non-optional ways kept the UMeshDescriptionProvider/Committer.

Procedural

New:

• Added a new Filter Elements by Index node that extracts the corresponding element(s), either point(s) or attribute value(s), from an index provided by an attribute on point or attribute set data.

• Add parse string node: Allow to convert any string into a predefined type.

• Added new Blueprint related event handlers for common PCG events.

  • OnPCGGraphStartGenerating

  • OnPCGGraphCancelled

  • OnPCGGraphGenerated

  • OnPCGGraphCleaned

• Added the collapse node that does decimation and averaging.

• Added 'In Graph Folder' and 'In Generated Folder' modes to the Create Target Actor and Spawn Actor nodes.

• Added a new Pathfinding node that will find one or more optimal path through a cloud of points when provided with a starting and goal point/location. It will also find the shortest path to any goal, if multiple goals are provided.

• Added the sort by tag value node which allows to sort data at the data level (useful to order data by priority, etc. in a very efficient manner).

• Added option to quiet attribute filter on data that's missing an attribute

• Added a "From Input" mode in the Get Actor Data nodes to allow for parsing of actors without doing a query.

• Added some overrides in the Get Actor Data nodes.

• Added the Attract node that allows to pair up source points with target points based on some criteria and a maximum search distance. This mapping (which can also be provided from an attribute) can then be used to do interpolation between source and target.

• Added a new Subdivide Spline node that will place grammar modules along a full spline path.

• Added a retrieval mode in the Get Parameter node (by name) to allow getting graph parameters from upstream or from the root without requiring to pass them down.

• [PCG] Refactor Copy Attributes

  • Match Copy Points API

  • Sunset Transfer Attributes, which will be replaced by Copy Attributes

• Added tags to the mesh descriptors used in the Static Mesh Spawner.

• Added a mode to retrieve actor references only in the Get Actor Data node (useful to delay actor parsing or early filtering).

• Added option in the Static Mesh Spawner to force the component choice to the user provided value.

• Added a new Visualize Attribute node, which can be used to display attribute information in world space.

• Add material extraction to the mesh sampler

• Allowed more overrides on Get Actor Property and Get Property From Object path nodes.

• Get Actor Property node now queries actor tags as well.

• Added some flexibility to allow retrieval of multiple properties assuming the same cardinality.

• Add a Spawn Spline Component node

• Added an 'unordered' option in the cull points from bounds node, which is going to be more efficient when there is a significant size difference between in/out bounds.

• Extended the C++ API to support partitioning on multiple attributes in PCGMetadataPartitionCommon.h.

• Added a new Select Grammar node that will select a grammar module for a given key based on a selectable criteria.

• Renamed the Apply On Actor node to Apply On Object and generalized its use to any object.

• Geometry Script interop plugin has a new example map for V1 of Geometry Script nodes.

• Add support for TSet extraction and in graph parameters

• Added the Wait For Landscape Changes node, which can be used in conjunction with an option on the graph to ignore landscape changes for graphs that interact with the landscape.

• Added the Save Data Asset node to export any input data. Added UI element to save collection/specific data being inspected to an asset.

• Added the Add Component node that can add components to specified actor(s).

• Changed the default spawn option in the Spawn Actor node to 'No merging'.

• Added the option to retrieve the reflection direction in the world ray hit nodes.

• Added component selection and filtering in the Get Data nodes.

• Allowed include/exclude of landscape hits on the world queries

• [PCG] V1 for Grammar support in PCG, with Shape Grammar (with Slicers)

  • Add a Spline to Segment to convert a linear spline into points, representing the segment

  • Add a Duplicate Cross Sections to duplicate a spline along an axis, following a grammar

  • Add a Subdivide Segment to slice a point into multiple points, following a grammar

• Added the Collision Wrapper node that interprets a point data as-if it were collision. This can be used as a volume or in the 'difference' part of the Difference node, but it will not work as the source.

• Added option to zoom on the data selected in the Attribute List View, and also added a contextual menu to zoom on selected rows (similar to the double-click).

• Add Remove Duplicates node, that will keep only unique values for a given attribute.

• Added a new Clustering node that will assign "clustering labels" to points based on a locational similarity, using one of the following traditional ML clustering algorithms:

  • K-Means

  • Expectation-Maximization

• Added a new Clean Spline node that can remove extraneous control points from splines:

  • Fuses co-located control points.

  • Removes collinear control points.

• Added steepness control on create points grid.

• Added exponential on grid size that shifts to the next (& more) cell sizes. For example, a cell size of 400 with an exponential of 2 will make it work as-if it were a 1600 grid (400 * 2^2). This can be useful for very large distances - allows grid sizes up to ~2000km.

• Added a collision-aware mode in the Self-Pruning node. Note that it is very expensive, and relies on good bounds. Added the Set Bounds From Mesh node to act as a preamble to the self-pruning.

• [PCG] Replace Density Remap by Attribute Remap

  • Node is using Metadata Operation base

  • Deprecate old Density Remap

  • Add preconfigured info for Density Remap, using Attribute Remap

  • Change the Unit Test to use Attribute Remap now

• Added replace string operation in the String operation node.

• Normalized attribute filtering parameters in the filtering/delete attributes nodes so they are a bit more flexible (e.g. substring match, etc.)

• Added support to the Static Mesh Spawner for "Property Overrides", which will automatically partition ISMs accordingly.

• Grammar feature has a new example map for V1

• Enabled the extraction of metadata from Ray Hits including:

  • Impact (T/F)

  • Impact Point

  • Impact Normal

  • Impact Distance

  • Local Impact Point

  • Physical Material

  • Render Material

  • Static Mesh

  • UV Coords

  • Element Index

  • Face Index

• Added a pause button & cancel mechanism to the toolbar, which can be controlled in the project settings.

• Added a new Create Points Sphere node with the following generation modes:

  • Geodesic

  • Angle

  • Segments

  • Random

  • Poisson

• Added multiple nodes to do tag to attribute processing and improved management of Tag:Value tags.

• [PCG] Add Elevation Isolines node

  • Use the Marching Squares algorithm, factorized in its own helper.

• Added option to get components reference in the Get Actor Data nodes.

• Added quality of life methods to simplify managed resource creation from blueprint (Add Component To Managed Resources, Add Actors To Managed Resources).

• Added support to load multiple assets in the Load PCG Data asset node. Fixed graph compilation/culling issue when switching from/to FromInput in the get actor prop/get actor data nodes.

• Added a new Primitive Cross-Section node that will automatically detect and output spline cross-sections from the combination one or more scene primitives.

• Added approximate data size in megabytes in the profiling window. Note that this is an approximation and in practice there are cases where we will reuse data in more efficient ways and so on.

• Added right-click -> copy column name in the attribute list view.

• Added a new World Raycast node that will return the point of impact for one or more customizable line traces with the option to extract information about the hit and the target.

• Made the texture sampler clearer with respect in how density is computed and added more options.

• Added per-data caching in elements that loop over their required pins. Requires opt-in per element, which is done in a separate CL.

• Added a new Print String node, which emits a log/warning/error to the log an optionally to the graph.

Bug Fix:

• Added extra security, controlled by CVars, to alleviate out of memory asserts in Surface and Volume Samplers, often from unbounded or extreme sampling.

• Fixed a bug causing the Volume Sampler to improperly sample the final row of X, Y, Z in certain situations.

• Added robustness to out of memory security measures in PCG Samplers to help mitigate continued crashes

• Fixed and issue with caching of the volume sampler results, which could be a problem in partitioned graphs.

• Fixed a bug with ISM Body Instance Customization not displaying the correct channels when viewed in PCG nodes, such as the Static Mesh Spawner.

• Removed unneeded data duplication in Get Actor Data.

• Fixed times in the profiling window for tasks that went to sleep or that were executed in parallel.

• Fixed bug where pasting an editor graph node that fails to import object properties will break the parser and crash the editor.

• Fixed a bug preventing attributes with spaces to be filtered by the Filter Attribute node.

Texturing Tools

New:

• Texture Graph Editor: The node preview is now using the new SImageViewport widget

UV Editor

New:

• Make the UV editor seam tool (and the modeling tools seam tool) follow paths better in certain "against the grain" situations.

• Added functionality to the UV Layout tool to allow for preserving existing UV island's scale and orientation during layout operations.

Bug Fix:

• Fixed issue where unwrap material was set with a depth offset multiplier that rendered mesh lines difficult to see in the unwrap view of the editor.

• Added localization text for missing transform tool categories defined by the detail's customization for the tool.

World Building

New:

• Add start/end/random offset to the PCG Spline Sampler

• Added Seeding Modes to the PCG Spline Sampler, and a new mode 'Seed From Index' to get stable seeds when points change position.

• Changed Pin/Unpin (user facing) to ForceLoad/ReleaseForceLoad in SceneOutliner

• Add PCGDataVisualization interface and PCGDataVisualizationFactory factory to implement custom debug/visualization behavior for PCG data types.

• [World Partition] Implemented asynchronous update streaming state. Can be turned on using wp.Runtime.UpdateStreaming.EnableAsyncUpdate true (disabled by default). This allows to run the computation of the world partition streaming cells to load/activate/unload outside of the game thread / critical path. Update of the cells underlying level streaming state and priority is still done in game thread.

• External Data Layer V1 - Allows for plugins to inject/remove content (actors) in a partitioned world - Serves as a replacement for the experimental 'Content Bundle' feature - Added new External Data Layer (EDL) Asset - Added new Game Feature Action 'AddWorldPartitionContent' to control activation of an EDL asset - Supports Data Layers inside a plugin (child of an EDL) - Added builder to convert content bundles to EDL (UGameFeatureActionConvertContentBundleWorldPartitionBuilder) - Feature is temporarily disabled by default and can be turned on using Editor Experimental Settings 'Enable World Partition External Data Layers' flag

• PCG Runtime Quality Branch/Select nodes. Added 'pcg.Quality' cvar ranging from 0 to 4 (Low, Medium, High, Epic, Cinematic).

• Support for cooking PCG graphs with GPU enabled nodes.

• Add option to compute alpha and distance along curve as attributes in PCG Spline Sampler node. Alpha is a value in [0,1] along the curve where each segment of the curve represents the same interval. For example, if the curve has three segments, points on those segments would lie in [0,0.333], [0.333, 0.666], [0.666, 1] respectively, and interpolate across those intervals using the spline's interpolation. Distance is the total cumulative distance along the spline to reach a given sample point.

• Provide a native GPU implementation of the PCG Copy Points node, enabled by setting bExecuteOnGPU flag to true in the Copy Points node settings

• Add command to refresh all PCG runtime gen components - 'pcg.RuntimeGeneration.Refresh'

• Add EPCGTextureFilter for Point and Bilinear filtering on PCGTextureData

• Add support to PCGDataVisualization interface for populating the Attribute List View window.

• Add 'Spawn Spline Mesh' node which spawns takes a Spline Data and spawns Spline Mesh Components in the world.

• Support attribute set data type in PCG GPU graphs

• Update PCG Instance Data Packers to use attribute accessors

• Add 'Create Surface From Spline' node for creating an implicit surface from a closed spline.

• Fixed spline interior sampling not respecting the Bounding Shape input correctly

• Allow PCG data visualizations to override double-click behavior in the Attribute List View window. Additionally, double-click on Spline Data entries focuses the relevant spline control point in viewport.

• Add PCGWaterInterop plugin, with 'Get Water Spline Data' node.

Bug Fix:

• [PCG] Bug Fix: Sanitize attribute names when creating from Tags to prevent spurious error messages thrown when Tags have characters not supported in PCG attribute names.

• World Partition Editor

  • Add ShowMouseCoordinates (World Position) in Show Menu.

  • Used the default GrabHandClosed cursor when panning.

• Add the ability to ignore the dirty flag when querying for external objects to save

• [PCG] Bug Fix: Eliminated frequent blocking texture loads in editor when using the Get Texture Data node.

• ForEachStreamingRelevantComponent now takes into account all UActorComponent when being invoked for editor.

• Source Control Changelist View

  • Fix initial refresh UI not being call for all changelist type (esp. the Uncontrolled Cl)

• Added redirector support to FExternalPackageHelper::LoadObjectsFromExternalPackages

• [PCG] Bug Fix: Fixed large freezes when using runtime generation in editor when many actors are present in level.

• Fix assertion when trying to break LevelInstanceActor when its level isn't current

• [PCG] Bug Fix: Addressed broken actor bounds when getting a point from an actor when the actor transform has negative scales.

• Fix Deleting Assets progress bar exceeding 100%

• Fix "Update Redirector References" process unable to fix up redirectors of assets used in level instances

• Add checks to make sure RepresentingWorld is valid before it's accessed.

• Fix warnings appearing after creating a new Empty Open World Level

Localization

API Change:

• The CookedLocalizationPaths setting is now deprecated because it serves no purpose anymore.

New:

• Centralized the logic for forcing game localization data to load in an editor

  • This is now controlled by FTextLocalizationManager::ShouldForceLoadGameLocalization, which will return true for: a cooked editor, or an uncooked editor with the game localization preview enabled, or with the CVar Localization.ForceLoadGameLocalizationInEditor set to true.

• Exposed EDateTimeStyle to Blueprint Date/Time Text functions

• Added "Localization.AlwaysLoadNativeLocalizationDataDuringInitialization" (default: false)

  • This allows games to opt-in to loading the native localization data during initialization, even if the game isn't starting in the native language. This ensures that all gathered text will load some localization data, even if not fully translated.

• Game localization data is now always loaded in cooked editors.

• Exposed FText::AsMemory to Blueprints

• Ref-count the mounting of localization data for explicitly mounted plugins

  • This allows different systems that need plugin localization to call MountExplicitlyLoadedPluginLocalizationData and UnmountExplicitlyLoadedPluginLocalizationData (in pairs), without needing to understand any other system that may have mounted localization for that plugin, and avoids the unmount calls from different systems fighting with each other.

Bug Fix:

• Remove restriction that the package localization cache can only be updated on the game thread

  • This restriction was added before the asset registry itself was made thread-safe, and is no longer needed

• Disable localization chunking when cooking DLC

  • Running this code as-is causes a name conflict in the DLC output that can override the base localization data when the DLC is mounted. This can result in most of the base localization data appearing to be missing, as the DLC may have been cooked against a much smaller set of packages in each chunk.

  • While this could be supported by adding a suffix to the chunked data within the DLC, plugin localization is a better way to achieve this, and so localization chunking is now disabled when cooking a DLC plugin.

• Add a Clang compiled ICU static lib for x64 to fix memory corruption issues at runtime when linking with Link-LLD.

• Fixed issue where NativeCultureIndex wouldn't be updated when deleting a culture, causing the native culture to be modified incorrectly.

• Validate that the requested OS locale is supported by ICU, and if not, use the requested language instead

  • We have some platforms that are returning unsupported locales (eg, a locale of en-IT, with a language of it-IT), so this change hardens the default locale set-up to validate that ICU has resource data for the requested locale, and if not, we use the requested language as the locale instead.

MetaHuman

New:

• MetaHuman component for UE improvements - Instance PP AnimBP will only be played in case the physics asset or the control rig actually differs the one set in the AnimBP of the skeletal mesh asset. This way we avoid any overhead work at instantiation time.

  • In case the control rig and physics asset set on the MH component match the ones set in the skel mesh assets, we still want to hook into the performance control, fixed now.

• Added MetaData map to DNA User Asset to store MetaHuman relevant data like body type.

• New: Added import path configuration to the project settings of the MetaHumanSDK plugin. This controls where imported MetaHumans will be added to the project.

• Move MetaHumanRuntime plugin to MetaHumanSDK plugin and rename it to MetaHumanSDKRuntime #changelist validated

• New: Added the experimental MetaHumanSDK plugin containing editor and runtime components supporting the use of MetaHumans in projects.

• Moving DNAIndexMapping and SharedRigRuntimeContext to public folder

Mobile Rendering

New:

• Add ReplaceTonemapper BlendLocation to the Mobile PostProcess

• Support Vulkan pre-rotation on mobile. - Create an intermediate image as the BackBuffer and render normally, then copy the image to the actual BackBuffer in the low level. - Remove the QCom pre-rotation implementation.

• Clamp number of active scene captures for mobile Deprecate calling GMaxNumReflectionCaptures and GMobileMaxNumReflectionCaptures directly to avoid errors in the future

• Allow Debug View shaders on ES3_1 preview platforms

• Removed SkyLight specific shader permutations. This halves total number of shader permutations in a projects with a stationary or movable SkyLights at a minor GPU cost.

• Merged Linear64 and Gamma32 shader variants as we do not support both permutations at the same time

• Added support for rendering debug primitives on mobile as part of the base pass when MobileHDR is disabled, as they would normally be rendered during post processing

• PSO pre-caching is now enabled by default for iOS Metal, Android Vulkan and Android OpenGL ES

• Added an option to not use "Pixel Local Storage" and "FrameBuffer Fetch" extensions on Android OpenGL. And instead rely on a regular texture sampling similar to immediate mode GPUs. Set r.Mobile.AllowFramebufferFetchOpenGL=0 to disable support for these extensions.

• Removed some of the complexity in static lighting shader permutation settings r.Mobile.AllowMovableDirectionalLights option was removed. Movable lights are always allowed. CSM from movable lights will only work in a non pre-computed lighting environment or when "Combined Static and CSM" option is enabled. Removed r.Mobile.EnableNoPrecomputedLightingCSMShader. CSM shaders will be generated only when project has "Combined Static and CSM" option enabled.

• "GPU Scene" is now enabled by default on all mobile platforms

• Added support for SSAO in a mobile deferred shading

Bug Fix:

• Allow modulate blend mode materials to be renderred in translucent after DOF pass on mobile.

• Apply sky lighting with ambient occlusion on mobile deferred.

• FSceneCapturePS has highp floats forced now to fix a driver bug FullPrecisionInPS can now be enabled on a per global shader basis and not just globally controlled by r.Mobile.FloatPrecisionMode

• Correctly change between Mobile Forward and Mobile Deferred, taking into account r.Mobile.AllowDeferredShadingOpenGL cvar

• Fix some issues related with CSM caching. 1. Fix an issue that the LastFrameExtraStaticShadowSubjects could be overridden when there are multiple Packets in FGatherShadowPrimitivesPacket. 2. Uses atomic add to count LastFrameExtraStaticShadowSubjects for multi-thread rendering. 3. Invalid the cached shadow map if the LastFrameExtraStaticShadowSubjects is greater than a throttle for both SDCM_MovablePrimitivesOnly and SDCM_CSMScrolling

• Fixed crash when Building Virtual Textures with the separate mobile SVT enabled

• Remove the DXT format support for Android OpenGL since the compressed RVT could be created with the DXT format but the compression method is ETC. ETC is aways supported on GLES 3.1.

• Fix a crash if there are more than 8 lights cast shadow on mobile GL platform. UniformBuffer can't be created on worker thread on GL.

• Fix up type of "OutColor" from "HALF4_TYPE" to "HALF_TYPE" in SunBlurPS_Mobile function ( PostProcessMobile.usf )

• Fix a bug that the scene is much brighter with reflection capture on mobile.

• Prevent mobile-specific SVT textures to be displayed if Virtual Textures on mobile is disabled in the project settings. If mobile support for virtual textures is to be used on certain mobile platforms only, the project settings should still be enabled (so that the editor can know that at least one mobile platform supports it) and those platforms should have r.Mobile.VirtualTextures set to 0 in the .ini files.

• Fixed and optimized PSO pre-caching for all mobile project configurations, like projects with pre-computed lighting, dynamic lighting and/or VR projects.

• Fixed precision issues with bloom on Android devices running OpenGL ES

• Fixed flicker when rendering primitives with refractive materials in a mobile deferred shading mode

• Fixed case where static actors were not rendered into a Stationary light Cascaded ShadowMaps in a project with a pre-computed lighting enabled.

Deprecated:

• Leave only immutable texture path for GL(only use glTexStorage2D), don't set GL_TEXTURE_MAX_LEVEL as it isn't needed anymore

Mobile Deferred

Bug Fix:

• Fix the GBufferA format for the mobile deferred with pixel local storage .

Mobile Forward

New:

• Added IES Textures in Mobile Forward Renderer

• Added movable point lights dynamic shadows in mobile forward renderer. Requires r.Mobile.EnableMovablePointLightsShadows=1 and r.Mobile.SupportGPUScene=True.

• Added rect light support to mobile forward renderer. Requires r.Mobile.Forward.RenderRectLightsAsSpotLights=0.

• Added capsule direct shadows to mobile forward renderer. Requires r.Mobile.EnableCapsuleShadows=1 and r.Mobile.EnableCapsuleDirectShadows=1.

Bug Fix:

• Fix depth prepass disabling MSAA.

Mobile Lighting

New:

• Force Lowerst Lod for Sky Capture on Android

Bug Fix:

• Don't do LightPrimitiveInteractions for local lights on mobile when r.Mobile.Forward.LocalLightsSinglePermutation is enabled and you don't have local light dynamic shadows enabled

Motion Design

New:

• Added option to hide actors while waiting for the Delay Task to complete.

• Renamed Mask Modifier Apply/set to Target/Source

• Motion Design Outliner displays Levels as top level items

• Added Default Transition Tree Template settings to build on new levels

Online

New:

• Change SocialChatManager in SocialToolkit to be protected instead of private

Bug Fix:

• A constant DedicatedServerId is now used by OnlineSubsystemEOS when the game is ran as server. This fixes a bug with session search where IsValid() was returning false on sessions created by a server. There are several other minor fixes and improvements to session and lobby search in this change.

• Added a IsValid() check on CurrentSessionSearch in StartLobbySearch to avoid potential crash

• Fix for EOS SDK cache directory to account for system account file path. Added some checks to set cache directory to nullptr in EOS SDK platform create and empty string in config

• Fix in RefreshConnectLogin to check Epic Games account only if EAS is used.

• Modified FOnlineSessionEOS::FindFriendSession to call the correct completion delegate.

Crash Reporter

Bug Fix:

• Fixed an issue where the Language Code Identifier was always 0 in crash reports.

Hotfix System

New:

• Added UCurveTable modification callback deferral in OnlineHotfixManager similar to what is done for UDataTable to save performance.

HTTP

New:

• Added support to IHttpRequest to specify a Unix Socket to send the request to, supported on Windows and Linux

Bug Fix:

• Fix a crash in the Curl HTTP implementation due to some curl state being manipulated on multiple threads under some circumstances

• Added configurable choice of Packet Reliability Type in EOS Sockets

• Update UAT to have the same default value for n.VerifyPeer as Unreal Engine. Fixes cacert.pem not being staged when n.VerifyPeer is not explicitly set to true in Engine.ini

Online Subsystem

New:

• Updated OnlineSubsystemGoogle's Google SignIn implementation. Added support for silent sign in and retrieving server auth code

• Added support to specify the type of auth in EOS external mapping queries

• Updated EOSSDK version to EOS-SDK-35276460-v1.16.3

• Refactor of PersistentAuth/AccountPortal login flow in UserManagerEOS. Addition of missing logic for proper EOS login flow on Switch when using NPLN.

• Added support for EOSSDK Native Platform Integration in Xbox platforms

• Addition of support for -epicdeploymentid and -deploymentid parameters to define EOS platform creation

• Removed -EpicPortal parameter requirement to initialize Ecom interface in OnlineSubsystemEOS.

• Added logic to Lyra to enable basic EOS beacon communication as part of the session creation and join flow.

• Update OnlineSubsystemGoogle implementation for iOS to include privacy manifests (Using Google Sign In SDK 7.1.0)

• Added implementation using CredentialManager and set it as default in OnlineSubsystemGoogle

• Added support for EOS_Connect_AddNotifyAuthExpiration.

• Update OnlineSubsystemFacebook on Android (updated to use Facebook SDK v17.0.0)

• Addition of support for new result of EOS_Ecom_Checkout: EOS_Ecom_PurchaseProcessing in OSS.

• EOSSDK binary update to version 1.16.4-36651368

• Added new test command line option GETFRIENDDISPLAYNAME to FOnlineSubsystemImpl::HandleFriendExecCommands

• Added support for EOS_Lobby_AddNotifyLeaveLobbyRequested, along with a new Sessions interface event and corresponding logic in CommonSessionSubsystem and CommonGameInstance reacting to it

• Update OnlineSubsystemFacebook to include privacy manifest on iOS (updated to use Facebook SDK v17.0.3)

• Addition of support for -NoEOS commandline parameter to stop EOS modules from loading.

• Add entitlements and microtransaction implementation support for Steam. The important addition for Steam is entitlements, Steam apps that can purchase another Steam app through the Steam store (commonly used for expansion packs or other types of DLC) will now have an entry when calling the purchase interface's QueryReceipts functionality. There is additional support added for Steam's microtransaction API as well. There is little we can actually do in the engine, because all of the API requires calls to and from a trusted backend server. For this reason, the Steam purchasing link was added. It is simply an ease-of-use feature for coders who implement all of their purchasing support via the Online Subsystems. Simply define a server link with calls for initiate transaction and offer querying and all of your existing purchasing code will work just as it does on the other platforms.

• Add EOS Integrated Platform support for Steam using the -CustomConfig=EOS command line option. This also includes the SteamEOS option to enable this in Lyra, but full Steam integrated platform support in Lyra is still a WIP

• Update the CreateSession BP node to include a "Use Lobbies If Available" boolean.

• Add sessions-based presence plugin for Lyra to enable some very simple functional testing of presence functionality in Lyra

• [Online Services] Implement OnSessionCreated and OnSessionJoined in the SessionsOSSAdapter so that an event is fired when a session is created and joined.

Bug Fix:

• Changed how OSS EOS Sessions responds to a EOS_ELobbyMemberStatus::EOS_LMS_CLOSED notification, destroying the related lobby instead of just removing the lobby member.

• Disable FOnlineError from being constructable from a bool Unbind FOnlineEventDelegateHandle on move assignment

• Fixed a bug where input did not respond while an EOS Overlay popup notification was showing.

• Fix wrong check on GooglePlay's achievements that succeeded

• Fix for override of the value the bUsesPresence in OSS EOS Lobbies

• Refactored NetDriverDefinition across all platforms. Removed GameEngine re-definitions in Platform config. Moved Platform config from Engine to BaseEngine.

• [OnlineSubsystem EOS] Fixed a crash in OnlineSubsystemEOS when accepting a friend request but the friend's list has not been populated yet.

• Fix Steam OSSAdapter for EOS ExternalAuth

• SteamSockets fixes SteamSocketsNetConnection has a custom handshake flow where it performs the handshake using the handler of the net driver, but this was causing problems after it was complete because the handler of the net connection did not have the data of the handshake (namely, the session and client IDs). This change synchronizes the two after the handshake is complete There were also some non-unity issues in the Steam sockets files that have been addressed.

• Github pull- GetPlayerNickname() Steam fix - use GetFriendPersonaName with 64-bit ID Developer note: Code has been reworked, but the target issue is the same

Deprecated:

• Deprecation of Stat/Leaderboard Interface variables and methods using FName, with new FString variants.

• Deprecated usage of SEARCH_PRESENCE in OSS Sessions

• Removed Online logic marked for deprecation in 5.3

• OSS EOS Login Refactor: - Added new login methods that act in a more deterministic way. Added config variable to use new logic. - Kept old methods renamed as Legacy. They are used by default. - Changed Lyra config to stop using EOSPlus and use new login flow.

• Deprecate IOnlinePartySystem::RejoinParty. This feature must be implemented as JoinParty.

Pixel Streaming

New:

• Added support to the Pixel Streaming blueprint component to use the -PixelStreamingURL command line value instead of whatever is set on the component property.

• [WebRTC] Fix: Rebuilt WebRTC with correct references to LibVpx.

• [AVCodecs] Add: LibVpx (software VP8 and VP9) support to AVCodecs

• [PS1] Add: FlexFec support to PixelStreaming

• [AVCodecs] Add: VP9 profile enum

• [PixelCapture] QOL: Update number of maximum capturers to support a larger number of concurrent streams

• [PixelCapture] Add: New MediaIO based PixelCapturer that handles RHI -> RHI and RHI -> I420 CPU conversion

Bug Fix:

• Fix: Pixel Streaming VR stereo images would not converge on Meta Quest 3 and Apple Vision Pro headsets. Additionally, reworked handling of XR axes, touches, and button presses in Pixel Streaming VR as they would sometimes result in no input or stuck input.

• Fix: In Pixel Streaming VR off-center eye offsets were applied incorrectly and this caused distorted stereo rendering in Meta Quest 3 and Apple Vision Pro headsets.

• Fix: Pixel Streaming VR controller Y-axis was inverted.

• Fix: The number of connections returned by embedded C++ signalling server (used by editor streaming and VCam) was inaccurate if multiple streamers were started and you queried before they had finished identifying themselves.

• [PixelCapture] Add: I010 pixel format support. NOTE: No capture pipeline exists for I010 data. This buffer exists purely to copy converted I4xx data in to.

• [PS1] Fix: StreamerComponent not working with internal signalling server.

• [AVCodecs] Fix: Re-add external semaphore deletion as it was accidentally removed in CL29731260

• [AVCodecs] Fix AVCodecs NVDEC crash when video resizes larger than original size.

• [PS1] Fix: PIE viewport streaming when there are other non-PIE game instances running (ex: Motion Design rundown)

• [AVCodecs] Fix NVENC AVCodecs crash when video resize larger than max device resolution.

• [AVCodecs] Fix: Update QP range for AV1 vs H.26X in NvEnc

• [AVCodecs] Fix: Warning logs produced from running NVidia driver check on non-NVidia GPUs

• [AVCodecs] Fix: VTCodecs hardware decoding. NOTE: There is a known memory leak with this codepath but will be addressed in a later CL

• [PS1] Fix: Pixel Streaming blueprint components running unnecessarily even when unused in scene

Deprecated:

• Un-deprecate "kick" blueprints in Pixel Streaming 1.

Platform

API Change:

• Programmers can use FScopedFTZFloatMode wrapper struct to place on top of the scopes where they need to flush denormals to zero to avoid manual handling of said cases. It's implemented for both x64 and ARM architectures

New:

• Replaced PLATFORM_SUPPORTS_VECTOR_ROUNDING_MODE with PLATFORM_SUPPORTS_VECTOR_CONTROL_REGISTERS, and replaced VectorSetControlRegister, VECTOR_ROUND_TOWARD_ZERO, and VECTOR_DENORMALS_FLUSH_TO_ZERO with noops when PLATFORM_SUPPORTS_VECTOR_CONTROL_REGISTERS is false

• Make Turnkey persist UE_SDKS_ROOT to .epicrc on Mac and Linux

• Implemented denormals flush to zero and round to zero floating unit control flags Plus fixed ARM FPU control flags API

• Allow editor to load non-confidential platform extension DeviceProfiles.ini files - Always load the GlobalDefaults DeviceProfile object, not just when ALLOW_OTHER_PLATFORM_CONFIG is defined - Allow a couple of dp exec commands when ALLOW_OTHER_PLATFORM_CONFIG is 0

• Moved all versions from *SDK.Versions.cs files to *_SDK.json files - Some static variables made it tricky, so added some support to make it simpler on users of the static variables

• Leave only immutable texture path for GL(only use glTexStorage2D), don't set GL_TEXTURE_MAX_LEVEL as it isn't needed anymore

Bug Fix:

• Fixed an issue where per-platform packaging settings were getting confused when project settings were changed in the editor (the per-platform ones were not getting updated).

• Changed Hybrid project checking to always check all enabled platforms to see if any need to be hybrid. This helps address an issue where a single-platform (say IOS) plugin was causing packaging to fail because the host platform (Mac) to clean up the hybrid target files, so then packaging for IOS would fail to find the compiled hybrid targets

Desktop

New:

• Use ITargetPlatformSettings instead of ITargetPlatform for Windows, Mac and Linux TargetSettingsDetails

• Desktop Platforms  TargetPlatform(TP)  Refactor TargetPlatformControls(TPC)/TargetPlatformSettings(TPS) for Windows/Mac/Linux/WINGDK

Linux

New:

• Fork

  • Added cvar fork.ParentSleepDurationInSec to give ability to configure the time parent process sleeps when it has no signals to execute

  • Added cvar fork.LogMemoryStatsWhenForking to control the memory stats log before every fork (enabled by default)

  • Added LogFork category used by fork related logs (previously LogHal)

• Add support for -fsanitize-recover for ASAN which allows builds to continue on error [RN] Linux ASAN builds will now include fsanitize-recover to allow continue on error

Bug Fix:

• Fix FUnixPlatformProcess::GetDllHandle issue when non-module shared libraries are reloaded

• Write protecting GModuleSymbolFileMemory to better be able to identify the root cause of crash during ensure stack walking

• Prevent GModuleSymbolFileMemory from being freed if it's size exceeds SSIZE_MAX. Cleaned up some logging and code duplication

Deprecated:

• Linux toolchains earlier than v23 are now deprecated since they cannot properly link for Rocky Linux 8

• Toolchain upgrade to llvm 18.1.0 - support Rocky Linux 8 as minimum supported OS - deprecate CentOS 7 support

Mac

New:

• Metal RHI now uses Bindless when enabling SM6

• Metal RHI Context Refactor Removed MetalContext and MetalRenderPass. Most functionality is now within MetalRHIContext and removed dependancies so that multiple MetalRHIContext's can execute in parallel.

Windows

New:

• Improving support for Windows arm64 - compilation fixes and many third party libraries compiled for arm64

XR

New:

• IOpenXRExtensionPlugin::UpdateCompositionLayers - headers array should not be of pointer-to-const -Removed const so that extension plugins can add new chain structs via the next ptr. -Fixed passing pointer to openxr chain struct that goes out of scope. -Removed a couple 5.1 deprecated functions from IOpenXRExtensionPlugin.h

• VisionOS: audio capture support -Add visionOS platform support

• Add CVAR to control whether we throttle the application when HMD is not worn -xr.OpenXRPausedIdleFPS created to specify the max fps when the openxr session is idle. When set to 0 there is no max fps. 10fps is the default. Setting it to 60 or 90 is more likely to be correct than 0, because with openxr idle the 'natural' max framerate may be faster than it is in vr. -Also changed OnStartGameFrame to avoid some useless work when we are not in an OpenXR session.

• Input Actions with the same description silently breaks OpenXR input -Detecting duplicate Action or ActionSet descriptions before we create them, issuing a warning, and then replacing them with the Action or ActionSet's FName so that the inputs will function.

• [OpenXR] One extension plugin adds multiple interaction profiles -Adds a hook to IOpenXRExtensionPlugin to add multiple interaction profiles. Previously only one could be added. -Deprecated the single interaction profile version, and replaced all uses of it in the engine.

• VisionOS hand tracking fix -Fixed tracked flag bit flag setting error.

• XR RHIGetDefaultContext usage elimination -Refactored so we don't use RHIGetDefaultContext anymore, instead we pass the rhicommandcontext down from OnBeginRendering_RenderThread or from RHIEndDrawingViewport through CustomPresent. -Added a DebugLabel to the swapchains, because i have often wanted one while debugging.

• Add Mac as a target/allow platform for the OpenXREyeTracker plugin

• Check to see if we're in an XR Tracking Only session and update tracking devices if we ar

• VR Template

  • Add visionOS specific .ini

  • Added support for reading VisionOS***.ini. IOS is a parent platform, so it's INIs are read as well.

  • Added VisionOSEngine.ini to vr template which disables MobileMultiview and InstancedStereoRendering, which are not currently supported.

  • Fixed build break where notification manager is used, but was not included on visionos. Perhaps it wasn't supported in an earlier version, but the types in question exist now so I just removed the ifdef removal on VisionOS.

Bug Fix:

• Fixed stereo layers depth not working in PCVR. Fixed crash when using the left texture of a stereo layer.

• Fixed shader compilation crash when enabling foveation on mobile due to CAS VRS not being supported.

• Fixed Bloom with mobile multi view and mobile hdr.

• Fix tonemapper being enabled in XR. Keep it enabled only in Editor windows as they need the linear to sRGB conversion that is done by the HW in the XR backbuffer case.

• Fixed Custom Depth and Custom Stencil for mobile multi view.

• MSAA depth working on VisionOS for both eyes

• Fixed editor crash using Rect Light with mobile multi view

• Fixed DBuffer decals for stereo rendering

• XRThreadUtils ExecuteOnRHIThread_Impl goes around rhi cmd list when it should not. -Removed the IsRHIThreadRunning() check. We don't want this command being executed out of order if the rhi command list is being used, even if there isn't a dedicated rhi thread.

• Fix crash when changing map with OpenXR foveation enabled

• Fix decals not rendering in stereo with ISR

• Fixed vulkan error log spam about using non multiview texture on multiview layout when depth prepass was enabled.

• Fix deferred mobile renderer base pass only rendering to the left eye with mobile multi view.

• Fixed volumetric fog for stereo rendering.

• Fixed VisionOS passthrough edge artifact

  • There was a race condition between acquiring a new depth swapchain texture and comitting to render into it. The result was that the depth buffer given to compositor services was occasionally one frame old. Because any 32x32 pixel block with all pixels at zero depth is dropped entirely this could result in 32x32 pixel bites taken out of the edges of rendered geometry abutting non-rendered passthrough areas of the output. This is fixed by moving the depth acquire to the same point as the color acquire. One must be running with the xr.OpenXRAcquireMode=1 for the fix to fuunction, in the other path the race condition still exists. This is now set in VisionOSEngine.ini. It is possible that this problem affected other VR devices which use depth for reprojection, but it would have been much more subtle.

• ensure() instead of check() if OpenXRPath cannot be converted to a strin

• Fix animated decals not rendering correctly in the right eye with mobile multi view.

• Fixed velocity rendering for mobile multi view

Deprecated:

• AzureSpatialAnchors deletion -Service retired November 2024, deprecated in 5.4. Time to delete it.

• Remove deprecated BeginRendering_RenderThread and BeginRendering_GameThread -Deprecated in 4.19. -Added cvar xr.LateUpdateManager.Disable, which disables late update of attached components.

Platform Mobile

New:

• Added HW Depth Resolve for Vulkan

• ASTC HQ mapping from BC7 is now configurable with new config DefaultASTCQualityBySizeHQ and respects per-texture quality override.

• Use VS2022 to build etc2comp library since its a required VS version since UE5.4

Bug Fix:

• Set proper user agent on mobile WebView browsers

Android

New:

• Implemented FPlatformMisc::SetStoredValue, GetStoredValue and others on Android

• Memory mapped animations and audio are now enabled on Android to save memory.

• Add SharedPreferences accessors for Android

  • bool AndroidThunkCpp_HasSharedPreference(const FString& Group, const FString& Key)

  • void AndroidThunkCpp_SetSharedPreferenceBool(const FString& Group, const FString& Key, bool Value)

  • bool AndroidThunkCpp_GetSharedPreferenceBool(const FString& Group, const FString& Key, bool DefaultValue)

  • void AndroidThunkCpp_SetSharedPreferenceInt(const FString& Group, const FString& Key, int32 Value)

  • int32 AndroidThunkCpp_GetSharedPreferenceInt(const FString& Group, const FString& Key, int32 DefaultValue)

  • void AndroidThunkCpp_SetSharedPreferenceString(const FString& Group, const FString& Key, const FString& Value)

  • FString AndroidThunkCpp_GetSharedPreferenceString(const FString& Group, const FString& Key, const FString& DefaultValue)

• Updated to AGP 8.5.2

• Added support for HWAsan starting from NDK 26

• Switched Android configurations to build with ISPC enabled by default.

• Move gc.MaxObjectsInGame, Substrate and NumPreallocatedVertices settings from Android Platform ini to Base ini

• Added support for debug keystore

• Flavorless 'Android' target platform now defaults to ASTC flavor

• Add device profile to support Xclipse devices running the SM5 renderer Rearranged Android SM5 device profiles to add vendor-specific defaults

Bug Fix:

• Fixed quick launch not working on Android when using Zen Store and target device and host are on different networks

• Do not attach network connection monitoring to PSOService processes

• Block AFS token from inclusion in packaged ini

• Fixed issue with UnrealAndroidFileTool packages command not including all installed apps

• Introduce short names for both AndroidTargetPlatformControls and AndroidTargetPlatformSettings, which are causing certain built targets to run afoul of the MAX_PATH limit we impose on UBT file path lengths.

• Fixed updating device orientation in Android's onConfigurationChanged callback. This fixes the cached in-engine value for current device orientation being completely wrong in some particular situations.

• Fixed issue with HMD initialization on Android

• Fixed output directory issue for Blueprint APKs

• Fixed order of arguments when using AFS to push libUnreal.so outside of .apk

• Fix a crash when generating a patch with a pak larger than 2GB.

• Added additional location to check for Android Studio binary

• Fixed issue with Android environment variables not always set on Mac

• Better handling of pread/pwrite for Android filesystem

• Fixed vulkan PSO cache when using Zen streaming

• Change method of ordering AndroidFileServer (AFS) startup sequence (am start -W doesn't work for older Android)

• Only kill Java tasks started by MakeAPK on build machines

• Fixed issue with incremental building growing the APK size when only .so files change

• AutoSDK for Android is now on -27

• Upgraded Swappy to code based on the latest in AOSP. We now manually load libswappy.so as a shared library built with static libstdc++ and hidden symbol visibility, isolating it from Unreal's allocator which would sometimes cause crashes during rotation or backgrounding.

• Fixed Android_Multi builds incorrectly treating ASTC_NormalRG as ASTC_NormalLA

• OpenGL: Correctly set 'Layered' argument in a glBindImageTexture call for a Texture2DArray resource

iOS, tvOS, and iPadOS

New:

• Added caching of FIOSPlatformMisc::GetNetworkConnectionType result to avoid redundant checks

• Memory mapped animations are now enabled on iOS to save memory.

• Add MallocBinned3 to iOS

• Refactored iOS background downloading stack

• Added MarketplaceKit.framework wrapper

• Change the slack growth factor from 1.25% to 1.2% IOS

• Add IOS as supported platform for MobileFSR

• Enabled UE_BINNEDCOMMON_ALLOW_RUNTIME_TWEAKING for IOS

• Autosdk MetalDeveloperTools support On Win64 MetalShaderFormat module is always loaded

• Added option to order CDN's by ping time on iOS background download

• Implemented ScheduleLocalNotificationAtTimeOverrideId on iOS

• Added ability to retry stale background downloads when we're in foreground on iOS

• Added CDN re-ordering for background download to potentially improve chances of reply at the first try

• Do not add StoreKit framework dependency for apps not distributed through the AppStore

• Improved Commit\Decommit memory syscalls on iOS and Mac to reduce RSS

• Optimized compiler and linker flags for iOS

• Added "ResignApp.sh" (meant for IOS but should work for Mac apps also) that can resign a .xcarchive, .app or .ipa with another cert/provision pair, and can change bundle ID, embedded commandline, build version (like 0.1.1234) and marketing version (like 1.0)

  • Run Engine/Build/BatchFiles/Mac/ResignApp.sh with no params for help

  • An .xcarchive can resign to any type, .app and .ipa can output to each other, but cannot output to .xcarchive (because we re-use the directory structure of the input .xcarchive)

• Added support to use zipped xcframeworks dependencies

• IOS/TVOS/VisionOS TargetPlatform(TP) refactor to TargetPlatformSettings(TPS)/TargetPlatformControls(TPC)

• Added an optional array RequiredEntitlements to [/Script/IOSRuntimeSettings.IOSRuntimeSettings] in the Engine.ini file. The app checks for these at startup and logs a fatal error if the entitlements are not found. This can help verify the app is signed with a key with the correct entitlements during development.

• Added support for a static feature level on iOS

• Added the UnrealAutomationTool command GeneratePsyms that can generate a .psym file for use with Unreal Insights from an iOS .dSYM file. The tool is intended to be run from the UnrealAutomationTool command line using

  • _./RunUAT.sh GeneratePsyms -files=MyProject/Binaries/IOS/MyProject.dSYM _or using a SymGen node in the BuildGraph xml.

• libimobiledevice improvements

  • idevicefs added -r option for rm, to remove recursively

  • idevicefs push/pull is an order of magnitude faster

  • idevicefs ls now shows directories and filesizes

  • removed debugging log from itcpconnect and the return code now indicates success/failure

Bug Fix:

• Added support for partial file writes on iOS

• Fixed several #ifdef 's that should be #if (caused Mac code to execute on IOS)

• Support Web Auth to complete using an external browser

• Update command line arguments only on when app is open with expected game schema

• Changed handling of file write returning 0 as an error on iOS

• Enabled ApplicationReceivedScreenOrientationChangedNotificationDelegate in engine pre-init on iOS

• Fixed several issues with a mobile deferred shading on iOS that were causing crashes and incorrect rendering.

• Fixed cases where drawable surface could leak

Quixel

Bug Fix:

• Fixed a crash that would occur if the user dragged an asset to the viewport after closing the quixel bridge panel.

Render Pipeline(MRQ)

New:

• Added support for camera overscan to MRQ. MRQ now uses the camera's overscan property to set overscan, and MRQ overscan property has been changed to an override, which when enabled replaces the camera's overscan value with its own.

• Add reference motion blur parameter to Path Traced Render node in MRG.

Rendering

API Change:

• For external users of "r.PostProcessing.PropagateAlpha", calls to FindTConsoleVariableDataInt(..) will need to be replaced with regular FindConsoleVariable(..), since the former call would silently fail on a (now) boolean console variable.

New:

• Hair - Add project settings for hair tristrip geometry as not all project are compatible with this.

• Hair - Split direct lighting loop for GBuffer & Hair inputs. This avoids context switching between each light and improve performance overall, and give a 5% improvement.

• Hair - Change groom skinning to use mesh's vertex normal instead of face vertex normal. This helps smooth the groom look when the underlying mesh has rough triangulation.

• Hair - Add hair show flags to disable hair rendering on certain view.

• Implemented native support for rendering first person geometry with an (effectively) different FOV and a smaller scale as to minimize the chance of clipping with the scene. The feature is controlled by the FirstPersonFieldOfView and FirstPersonScale properties on the camera component (or alternatively directly on the FMinimalViewInfo). Primitives can be tagged as first person by ticking the "IsFirstPerson" checkbox on the primitive component. Should support most primitives, including Niagara systems. The different FOV and scale is achieved with a 3x3 matrix multiplication that is applied in the shader after WPO. This matrix scales the geometry towards the camera and also scales the XY components in view space to cancel out the scene FOV and to achieve the intended first person FOV. This means that the first person geometry is modified in world space before any projection, so the rest of the renderer doesn't need to deal with a separate projection matrix (and related matrices), but it also means that we're lighting fairly small and slightly deformed geometry. In practise, the morphing seems to be acceptable. The scaling appears to be mostly inconsequential for for lighting and reflections, but scene shadows cast onto the first person geometry are a bit more binary. Self-shadows and casting shadows onto the scene are problems that will be solved in separate CLs. For now it is probably best to untick "Cast Shadows" on the first person geometry.

• Replaced the previously called "Enable alpha channel support in post processing" (r.PostProcessing.PropagateAlpha) renderer setting with an "Alpha Output" boolean located in the Default category, effectively removing the "linear-only" constrained option with value "1".

• Hair - Improve noise on hair transmittance and shadow. Replace the jitter noise by a blue noise function which remove structural noise, and lead to more pleasing results.

• Added ECVF_Scalability flag to r.Shadow.NaniteLODBias

• Added tonemapper and post-process materials to visible scene capture show flags.

• Handle multiple views when computing visibility masks for per-instance occlusion queries

  • Add a shader permutation to load previous visibility mask values before setting/clearing the visiblity bit for the current view

• DirectionalLight : Add a setter for AtmosphereSunDiskColorScale on the proxy so we don't need to fully recreate the renderstate each time it changes. This avoids 20ms spikes on the render thread

• Cleaned up and reduced tonemap shader permutations for faster compilation.

• Hair - Allow AutoLOD bias to have negative value.

• Added DumpMaterialInfo commandlet, which writes a CSV with properties of all matching materials to disk.

• [LWC] Implemented invariant operators on specific platforms that have issues with fast-math and the 'precise' keyword. Platforms that have invariant instruction intrinsics use those. On some platforms the FMA intrinsic is used, where it has the same invariance effect.

• Hair - Add group color to CV visualization, reference point / position offset, and large point visualization option.

• Local Fog Volumes now work with per pixel fog option on materials.

• Hair - Add experiemental screen trace for hanlding occlusion test when integrating Lumen input for hair (Enabled/disabled with r.HairStrands.SkyLighting.ScreenTraceOcclusion).

• Hair - Add Depth of Field Use hair depth property on PostProcessVolume.

• Hair - Save Hair Strands Textures generation options into groom strands to avoid re-entering them each time textures are generated.

• Added new (deferred) renderer project setting for primitive alpha holdout support, separating it regular propagate alpha which now becomes runtime-toggleable (POST_PROCESS_ALPHA has been completely removed).

• Added public custom render pass option to render scene color with/without alpha, in addition to the existing scene color with depth render mode.

• Added a new FirstPersonOutput node which allows users to pass a FirstPersonInterpolationAlpha value to interpolate between world space and first person space on a per-vertex frequency.

• Add support for CommandLine versioning within a run so parse results can be cached safely Cache IsHDRAllowed cmd line parse results as it is called per window per frame in slate

• Added a project setting, r.GPUSkin.AlwaysUseDeformerForUnlimitedBoneInfluences, that allows you to enable Unlimited Bone Influences in a project without compiling extra shader permutations for GPU skinning. This saves runtime memory, disk space and shader compilation time. When the setting is enabled, any mesh LODs using Unlimited Bone Influences that don't have a deformer assigned will use the DeformerGraph plugin's default deformer. This ensures that UBI meshes are always rendered with a deformer, and therefore the GPU skinning permutations for UBI aren't needed. Also added a per-LOD setting that allows users to disable mesh deformers on a specific LOD, which could be useful for controlling performance, e.g. disabling an expensive deformer on lower LODs. Some changes to functions on USkinnedMeshComponent lay the foundations for having different deformers on different LODs as well.

• [VSM] Added VSMTexelDitherScale to light proxy, analogous to r.Shadow.Virtual.SMRT.TexelDitherScale

• [VSM] Added VSMResolutionLodBias to light proxy, analogous to r.Shadow.Virtual.ResolutionLodBias

• Hair - Add VSM multiple sample support for hair strands voxel tracing, allowing to reduce noise on shadow cast by grooms.

• Re-implemented MeshEdges showflag. This fixes issues with z-fighting, TSR ghosting, missing Nanite geometry and adds flexibility in the composition step. The wireframe overlay is now rendered as a separate pre-pass, and composited into EditorPrimitives after the main pass.

• Added bTargetArraySlicesIndependently to UTextureRenderTarget (relevant for 2D arrays and cube or cube array) so that each slice can be individually rendered to by a pixel shader

• Don't allow setting MSAA with deferred shading in renderer settings as this combination is not supported.

• Hair - Fix missing control point when enabling triangle strip geometry for hair strands.

• Improved Blue Noise textures using "FastNoise: Filter-Adapted Spatio-Temporal Sampling for Real-Time Rendering". Improves quality of various stochastic effects like Lumen, MegaLights, Hair, Volumetric Fog relying on BlueNoiseScalar and BlueNoiseVec2. #virtualized

• Hair - Improve Groom importer warning/error reporting. Add report of invalid position.

• [LWC] Added the LWC complexity debug viewmode, similar to the shader complexity view, which shows how much LWC function usage each material has.