Unreal Engine 5.8 Release Notes

What's New?

The release of Unreal Engine 5.8 brings further improvements to the UE5 toolset. This release delivers improvements in a wide variety of areas, including Rendering, Character and Animation, Worldbuilding, PCG, 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 5.8:

AlexanderVeselov-arm, AlexBlackfrost, Almax27, andreibazi, az6667, Bit-Rot, Brian-PD, brpendle-ti, bturner, chrysos8201, ckendal3, ColinGulliver, CookiePLMonster, Darcy3000s, dasherman-ea, davidbaack, dmergele, DoubleDeez, DrewWeth, DTG-Will-Marshall, dyanikoglu, erebel55, Eric2-Praxinos, Erlandys, faisa-believer, foobit, gamethread, geordiemhall, glecko, GreenLightning, guansdu, H3mul, IngSubstance, iniside, jamesfAnet, jamespark-unreal, JasonCoombs, jdamdami, jerobarraco, jeysym, Jiboo, JohnJFarrow, Jordonbc, jorge-axiomvfx, jorgenpt, jpritchard1010, KaosSpectrum, KarimLUCCIN, KeithRare, kimkun07-k, kissSimple, klukule, KXOC, laurencei, lclara-BARB, LHG-JonAnderJimenez, ligazetom, LightKL, lsandersljungberg, LucaFranzo98, Maigo, MarcusSvensson92, Mario-Azcona, MartinWickhamFB, Mattiwatti, melku, michael-buschbeck-ms, Minus4-44, moumee, nickdarnell, phochstrasser, PICO-XR, QRare, r457-Ao2, rdunnington, reduf, redxdev, RiotJDebern, rohyunsang, sareali, serhanio, SilverWinter0511, slonopotamus, SoulSharer, sportbikerr1, ssutherland-riot, SukenderDontNod, Sythenz, teddemunnik, tioez326, tokyocplusplus, Tt-Wes, tustanivsky, Vaei, vladbelousoff, vogoltsov, WangKan, Wizzard033, wmiller, x157, yangskyboxlabs, yoonbigbear, zachlute-arenanet, ZeroEightSix, ZeroErrors, zhou-

Rendering

Megalights

Megalights is now entering Production Ready status with Unreal Engine 5.8. We greatly reduced noise to maximize visual fidelity, while also improving overall performance to achieve 60fps. We also introduced new tooling to help debug and optimize your scenes. 

Features Support

• Transmission support (subsurface scattering)

• New Froxel-based translucency support

• High quality front layer translucency lighting

• IES support for volumetrics and translucency

• Lighting channels support

• Cloud shadows

• First-person perspective weapon support

Visualization Views

• Light finder tool (debugging and optimization)

• Ray visualizer tool (ray iteration count)

• Shadow caster and shadow caster mismatch view

For more information on this feature, see MegaLights.

Lumen Lite (Beta)

Lumen Lite is a new medium-quality setting for Global Illumination using Irradiance Fields with Probe Occlusion supported by Lumen. It's twice as fast as Lumen high quality - which targets 60fps on PlayStation 5, while maintaining the art direction for games that rely on Global Illumination. This path is the new default for current-generation handheld consoles, where it can be used at 60fps, and it is supported on PC as well.

For more information on this feature, see Lumen Technical Details and Lumen Performance Guide.

X-Rite AXF Materials as Substrate

We’re adding support for importing measured materials from X-Rite’s AxF format into Unreal Engine, using the Substrate material system.

This feature gives automotive and industrial visualization teams a way to bring high-fidelity, real-world scanned materials—exported from X-Rite Pantora—directly into Unreal Engine.

FSSS - Fog Screen Space Scattering (Experimental)

With Unreal Engine 5.8, we introduce an experimental Fog Screen Space Scattering (FSSS) feature on the Exponential Height Fog component that approximates multiple light scattering within participating media—making dense fog, smoke, and dust appear blurrier and more integrated with the scene by simulating how light scatters through volumetric effects.

It supports all Volumetric Fog and Local Fog Volumes, with configurable controls for scene color integration and scattering spread, though Volumetric Clouds and Heterogeneous Volumes are not yet supported. As an experimental feature it currently offers only a single blur quality level and may exhibit visual artifacts.

Substrate NPR Shading (Experimental)

With Unreal Engine 5.8, we introduce experimental Substrate Toon Shading, a stylized non-photorealistic rendering solution built on the Substrate Blendable GBuffer (legacy) mode. It supports all light types including local lights, sky lights, and Lumen global illumination, and exposes precise control over diffuse and specular response through a new Substrate Toon BSDF and Toon Profile asset.

Substrate NPR shading features include ramp-based diffuse and specular control with dithering, self-shadowing extinction with hatching patterns, anisotropic specular highlights, and global illumination scale controls. 

Character and Animation

Modular Control Rig Improvements

In Unreal Engine 5.8, we’ve focused on improving stability and day-to-day usability of Modular Control Rig. These updates address long-standing friction in hierarchy management, module authoring, connector workflows, and mirroring behavior.

Display

• New Show Empty Sockets Only viewport option that simplifies dragging and dropping modules and helps enable building sockets on top of modules.

Hierarchy and State Persistence

Improved reliability and consistency of the rig and module hierarchies:

• Rig hierarchy and module hierarchy now reliably retain state after compilation.

• Fixed an issue where interacting with class settings in rig modules could cause the rig hierarchy to disappear.

• Resolved an undo/redo issue that could clear the entire rig hierarchy.

• Modular hierarchy filter settings now persist across sessions.

• Fixed an issue where selected controls could remain stuck after compiling dependent modules.

• Schematic Viewport visibility now persists across editor sessions.

• Module rig class fields now display both asset name and full asset path.

• Shift-click and MMB-click now expand or collapse children in the module hierarchy.

• Module hierarchy tree is now more compact and readable.

• Module hierarchy search now includes module class when that column is visible.

• Added options to show or hide the Connector and Module Class columns.

• Added hotkeys to show/hide optional, secondary, and unresolved connectors in the module hierarchy.

Module Authoring and Creation Workflow

Streamlined common authoring tasks and improved discoverability:

• Modules can now be duplicated using a right-click in the module hierarchy.

• Added a hotkey for duplicating modules.

• Dragging and dropping modules now automatically enables schematic view.

• Added Control Rig Module to the Create Control Rig Asset menu.

• Added a hotkey for creating new sockets.

Connector System Improvements

Significant quality-of-life and rule-handling improvements for connectors:

• Shape Types are now selectable from a dropdown in the Modular Rig editor.

• Connector descriptions defined in a control rig module now appear as tooltips.

• Array connector reorder handles are now visible by default.

• Non-draggable connectors display a plug icon and show connections via tooltip.

• Enabled drag-and-drop of connectors directly from the Details panel.

• Added support for showing/hiding connector and module class in the hierarchy.

• Delete all now correctly clears array entries in the Details panel.

• Fixed inability to remove all connections from array connectors.

• Fixed non-array connectors incorrectly appearing as arrays in Details.

• Added min/max rule support for connector arrays.

• Added Set Default Match support for connector arrays (supports single connectors and wildcard arrays).

• Enabled adding default targets to empty array connectors.

• Prevented full hierarchy and Details panel refresh when editing array connectors.

• Improved connector resolution when duplicating modules with child modules.

• Connector selection now correctly respects connector rules in module details.

• Fixed a rare crash when editing connector rules in control rig modules.

Mirroring Improvements

• Modular rigs now retain mirror input settings.

• Mirror modules now correctly mirror sub-hierarchies and multi-selection.

Skeletal Editor Blendshape Rigging Tools

Rigging and Blendshape Tools

Expanded face rigging and morph target editing tools in Unreal Engine 5.8 extend the Skeletal Editor and Control Rig to better support sculpt-driven facial workflows. These improvements strengthen in-engine blendshape authoring for stylized characters, custom skeletal meshes, and MetaHumans.

• Joint locking support during skinning workflows.

• Mesh element selection and editing for morph targets, with soft selection support.

• Hotkey to mirror (symmetrize) morph targets.

• Menu option to flip morph targets.

• New tool to split a morph target into two using a vertex map.

• Lattice deformer for morph target editing.

• Post-process geometry script for LOD generation (enabling simplified subdivision-style workflows).

• More consistent Move Brush behavior.

• Surface-based brush falloff.

We made quality-of-life improvements across Skeletal Editor tools to improve stability, usability, and production workflows.

Selection

• Maintain vertex/component selection when exiting Isolate Selected.

• Ctrl+click on buttons switches to new selection mode.

• Shift+click buttons to modify existing selections.

• Select bones directly from the Weights Component editor.

• Integration with the new unified gizmo system for asset editors.

Skinning and Weight Editing

• Fixed issue where adding weights to bones did not properly update the skeleton tree.

• Updated weight paint ramp widgets.

• Significant weighting tool improvements aligned with blendshape workflow development.

• New skin weight locking functionality.

  • Adjust weights between two influences without affecting others.

Bone Editing

• Mirror strings now work anywhere in the bone name.

• Support for mirroring joints across hierarchies.

• Fixed bone renaming issues.

• Fixed skeleton tree child selection visibility when collapsing hierarchies.

• Axis dropdown no longer incorrectly allows None.

• Added Local Rotation Axis (LRA) debug display.

• Added Orient Selected Bones Only option.

• Added Paste Special options for transferring joints between assets.

• Moved the Mesh and Bones menu to the top viewport toolbar.

Mesh and Morph Editing

• Added basic mesh element editing for base meshes and morph targets.

  • Currently supports moving selected elements.

  • Foundation for expanded editing capabilities.

Bone Count Reduction Tool

• New option to remove unused bones from skeletal meshes.

  • Removes bones not referenced by skin weights.

  • Preserves parent hierarchy to root.

Animate with Control Rig Physics (Beta)

Control Rig Physics moves to Beta, this release introduces new force-based functionality and expanded tooling to enable more physics-driven animation workflows.

Physics rigs now behave as layered rigs, compositing naturally on top of existing animation without requiring an explicit layered rig setup.

These updates enhance both rig authoring and animator-facing usability, particularly within Modular Control Rig.

What's New:

• Support for applying forces directly within Control Rig Physics.

• Ability to animate forces over time for dynamic rig behavior.

• Runtime performance improvements.

• Improvements to the way “alpha” works to blend between simulation and pass-through.

• New physics modules for Modular Control Rig to simplify physics setup.

• New physics utility rigs in the animator kit to assist animators working with physics-driven rigs.

These improvements expand the creative range of physics-based rigging.

Dynamics - Particle Based Physics for Control Rig

Control Rig Dynamics is a new, lightweight particle-based solver built directly into Control Rig for high-performance in-game character simulations.

This plugin is designed for fast, authorable physics for cosmetic elements like clothing, hair, and accessories without the overhead of full physics engine capabilities.

What's New:

• New Control Rig Dynamics plugin with a dedicated particle-based solver built for real-time performance.

• 5x runtime performance improvement over existing physics solutions.

• Fewer nodes and a simplified authoring workflow to reduce setup complexity.

• Purpose-built for in-game cosmetics and physics-driven character assets.

Control Rig Dynamics gives technical animators and riggers a fast, practical path to physics-based character simulation.

Animate with Direct Mesh Controls (Experimental)

Direct Mesh Controls (DMC) enable control rig controls to be represented directly on sections of the skeletal mesh, giving animators a way to manipulate rigs by interacting with the character surface in-context. This introduces a new control paradigm that complements traditional static shape controls.

• Creation of mesh-based control groups that function as control rig controls.

• Direct selection and manipulation of mesh regions in the viewport and Sequencer.

• Co-existence with traditional static shape controls for rigs where mesh controls are not appropriate (for example, tails, mechanical rigs).

• Viewport-driven click-and-drag interaction for faster object and rig manipulation.

Filters and Link System

We synchronized selection across Sequencer, Curve Editor, and the Viewport.

• Selection is now fully synchronized across the Viewport, Sequencer, and Curve Editor. Click a control on the character in the Viewport, pick a track in the Sequencer outliner, or select a curve in the Curve Editor — all three panels update together, instantly, every time.

• All your filters and searches are linked now by default as well. So anything you do in one of the editors is reflected in the other.

• The new Link icon lets you decide if you want this linked behavior or not.. When in an unlinked state you can decide what you're looking at in either view.

Simple View for Sequencer

Sequencer can now collapse down to a simplified view to give artists the freedom to focus on parts of the viewport while authoring animations.

• Collapse Sequencer view to a simplified timeline showing keys of:

  • Selected and pinned (any pinned tracks + selected actors/controls)

  • Selected (selected actors/controls)

  • All (everything in your sequencer)

• Expand the simplified timeline to full Sequencer view anytime

  • Hotkey to simplify (ctrl-backspace)

  • Hotkey to hide toolbar (shift-backspace)

• Functionality

  • Select multiple keys

  • Move, scale, copy/paste, delete

  • Snapping to frame and smart snap support

• Curated toolbar for character animation authoring

  • Add/remove in-betweens

• Options

  • Grid color blocks

  • Show/hide toolbar, transport controls, range slider

  • Customize colors, look, style

AutoBaking for Sequencer

We added new workflows for automatically baking to animation sequences and swapping back and forth between baked data and live control rig data..

• Added a new Configure AutoBake option to the right-click menu.

• Takes advantage of the linked animation sequences workflow.

• Added a quick toggle icon to anything that is configured with this autobake.

Animation Mixing in Sequencer (Experimental)

Expanding on the work done in 5.6 on seamless gameplay transition for cinematics, the Animation Mixer augments cinematic artists' ability to mix different animation input directly within Sequencer. This gives cinematic artists a way to layer and mask character animations for their sequences, without having the need of a separate animation Blueprint or specific slots. The Animation Mixer also supports workflows for the new Unreal Animation Framework.

With it, you can:

• Create animation mixers to assign to animation Blueprint slots or custom animation instances.

• Create mix layers to layer skeletal animation, control rig, or any input that affect the skeletal pose in a priority order.

• Mask bones and curves with a blend mask asset on any mix layer.

• Add modifiers to any mixer, layer, or section to bone match, offset root motion, mirroring, and more.

• Add transitions such as cross fading or dead blending between animations.

Foot Definition for Retargeting

For Unreal Engine 5.8, we continue to improve IK Retargeter, transferring foot animations across a wide variety of characters. Artists focusing on both runtime retargeting and motion capture workflows can use these new abilities to confidently get great results when retargeting to different characters.

• Define a foot plane and toes for the target character for better controlled transfers.

• Auto retargeting templates for retarget chains updated for foot definition.

• Additional control to prevent dampening of vertical pelvis motion on shorter characters

• Blend to Source, Scale Goals, and Offset Goals are split out in the IK Op Stack for more flexibility in ordering.

Retarget Override Sets

For gameplay retargeting workflows, Retarget Override Sets make it possible for a single IK retargeter asset to handle different retarget relationships without additional asset creation or extra Blueprint logic.

• Author a collection of ops and their properties to store as a retarget override set in the retargeter asset.

• Add and inherit from existing override sets for more flexible retargets.

• Bind ops and/or their properties to an animation curve or a variable in an override set.

• Set which override set to use when running IK retargeter for runtime retargeting or offline retargeting.

For more information on this feature, see IK Rig Retargeting.

RigMapper Animation Retargeting Tool (Beta)

We're continuing to improve Rig Mapper with better node graph authoring capabilities and further integration within the IK Retargeter to handle more completed facial animation transfers. It provides a way to transfer motion between different character setups, such as applying ARKit animations to MetaHumans or using MetaHuman Animator (MHA) animations on ARKit characters.

We expanded remap curves to a stack of ops to handle all curve retargeting operations in a priority order.

• The previous 5.7 workflow is now supported with the user data rig mapper op that handles rig mapper evaluation in array order.

• We provided a new single rig mapper op for users to assign a single rig mapper definition.

  • Create multiple single rig mapper ops in the remap curves stack to determine priority order of evaluation.

• We expanded the Rig Mapper Definition editor's nodal graph behaviors for a better user experience:

  • Create new nodes from the context menu or by dragging and dropping pins.

  • Drag and connect pins from node to node with contextual and directional awareness.

  • Move and arrange groups of nodes.

  • Updated the Details panel for every node with real-time edits visible in the graph.

Mutable

Mutable in UE 5.8 release reaches production readiness with stability, performance, and pipeline improvements.

Dataless customizable objects enable runtime-driven parameter handling for faster iteration, graph reusability, and better patching. They are optimized for mesh operations and simple texture composition.

Dataless workflows provide a way to evaluate parameter inputs at runtime instead of compile time, significantly reducing iteration cost while maintaining compatibility with Unreal Engine's packaging and encryption systems.

Skeletal mesh pin simplifies common workflows by giving users a way to work at the skeletal mesh level instead of mesh sections.

We made performance improvements across the board, including parallel updates to boost generation throughput for crowds, reduced game thread workload, and optimized mesh and texture operations.

For more information on this feature, see Mutable Skeletal Mesh Generation.

Live Link Face Video Streaming

Live Link Face on iOS and Android now streams video in real time directly to Unreal Engine, enabling on-set supervisors and directors to monitor an actor's performance as it happens. The video stream integrates with Unreal Engine Media Profiles, allowing you to review captured footage alongside solved animation. On newer devices, video streaming and real-time animation solving run simultaneously. The stream is designed to work reliably on low-bandwidth, high-latency Wi-Fi networks.

MetaHuman

Populate Your World with a MetaHuman Crowd

Assemble optimized instances of MetaHuman characters to create crowds compatible with Mass, scaling from tens to thousands of characters. The new experimental MetaHuman Crowd plugin provides a complete assembly pipeline with seamless transitions between high-fidelity individual actors and lower-fidelity Instanced Skeletal Meshes based on camera distance.

Key Features:

• Build collections of modular components (head, body, hair, clothing) and compose them by hand or procedurally using Blueprints.

• Optimized face textures that maintain visual fidelity with reduced memory footprint.

• Animation applied using Unreal Animation Framework or simple sequences depending on distance.

• Simulated with Mass, rendered using Nanite or dynamic LOD systems.

• Example project setup available separately, runs on all Unreal Engine target platforms.

For more information on this feature, see MetaHuman Crowds.

MetaHuman Creator

Turn Full-body Meshes into a MetaHuman Character, Ready to Animate

Convert any human character mesh with arbitrary topology into a fully-rigged MetaHuman in a single workflow. This improved Mesh to MetaHuman process conforms both head and body simultaneously, accepting input meshes of any topology and automatically generating results powered by the MetaHuman database.

Key Features:

• Combined head and body conforming in a single step.

• Accepts head and/or body mesh of any topology as input.

• Automatic results for human characters with manual control available for technical fixes.

• Ideal for characters created from scans, external GenAI/DCC tools, or existing character conversions.

For more information on this feature, see From Custom Mesh. 

Achieve Higher Fidelity or Alternative Visual Styles with Full Control of Unbaked Textures

Assemble MetaHuman characters without baked materials and textures. This allows granular lookdev and texture control for artists wanting to match a specific look. Author unbaked texture and material assets using standard Unreal Engine editors or export textures to external DCC tools. Options are provided to then override with user-customized textures and materials in MetaHuman Creator.

Key Features:

• Full control over textures and materials for custom visual fidelity or aesthetic styles.

• Modified unbaked materials and textures can be applied as overrides in the MetaHuman Creator for users to still benefit from the material baking when running default assemblies.

• Standard Unreal Engine workflow using familiar asset editors.

• Export capabilities for external DCC authoring.

Use Case: Enables looks beyond MetaHuman Creator's built-in capabilities while maintaining performance optimization.

For more information, see Unbaked Materials. 

Preview MetaHuman Characters Using Your Lighting Setup

Create custom lighting scenes in MetaHuman Creator to preview characters in the context of your target environment. Define lighting setups using templates that include skydome hemispheres, post-processing volumes, and light groups, then use these custom scenes to validate visual fidelity while authoring.

Key Features:

• Preview characters in your target lighting environment directly in MetaHuman Creator.

• Close the gap between MetaHuman Creator previews and in-level appearance.

• Inspect and modify viewport render settings for precise control.

• Ideal for character artists, lighting artists, and lookdev teams.

• MetaHuman Creator viewport now fully supports Lumen too.

For more information, see Custom Lighting Scenarios and Render Settings. 

MetaHuman Animator

Capture Body Animation from a Single Camera

​Capture body, or face and body performance, for a single actor from a single camera. This new experimental capability extends the accessibility of MetaHuman Animator from faces to bodies, removing the optical motion-capture stage as a barrier for content creators. Available as a standalone plugin on Fab and integrated directly into MetaHuman Animator, with the Live Link Face mobile apps updated to support body capture alongside face.​

Key Features:

• Body capture for a single actor from a single camera, with optional simultaneous face capture.

• Offline solve for high-fidelity results.

• Compatible with a wide range of consumer hardware including webcams and supported smartphones.

• Available as a standalone MetaHuman Animator Markerless Motion Capture plugin via Fab, and integrated as a capability of MetaHuman Animator inside Unreal Engine.

• Extended capture guidelines included in documentation.

For more information on this feature, see Animation from Mono Video Capture. 

MetaHuman Animator Streamlined Batch Processing

MetaHuman Animator offers an improved API for batch processing large volumes of captured performance data. The updated workflow covers the full pipeline, end to end, from solve through animation review and export. Reference Blueprint examples will be included to extend or customize for your specific pipeline.

MetaHuman Animator Available on Linux and macOS

MetaHuman Animator now supports Linux and macOS, expanding the availability of the Unreal Engine editor and MetaHuman Creator across platforms. You can generate facial animation from performance capture on Linux and macOS, without requiring access to a Windows machine. However, body animation features are currently only available on Windows.

Key Features:

• Offline and real-time facial MetaHuman Animator functionality available on Linux and macOS.

• Platform parity with Unreal Engine editor and MetaHuman Creator.

• Real-time facial animation on Linux is only available using Live Link Face.

Improved MetaHuman Animator Solve and Curve Quality

New real-time and offline animation models deliver improved solve quality across a wider range of capture conditions, including varied camera angles, lens distortion, and infrared lighting. Audio-driven animation benefits from a new real-time model. Curve output is more animator-friendly, with cleaner activation on key poses for easier editing and refinement.

Worldbuilding

Mesh Terrain (Experimental)

A next-generation mesh-based terrain solution to support large worlds using 3D modeling, layering, virtual texture, generic editor tools, variable tessellation, and Nanite. Our aim with this feature is to replace and remove the typical constraints of the current heightfield-only landscape solution in Unreal Engine.

For more information about this feature, see Mesh Terrain.

Fast Geometry Streaming (Experimental)

In the Fast Geometry Streaming plugin, we included multiple new improvements for speed, stability, and use cases support, over the initial 5.6 release.

• Added decal, point, spot and rect lights components support.

• Added support for mesh paint textures in the static mesh component.

• Added more functionality in IPhysicsBodyInstanceOwnerResolver:

  • GetCollisionObjectType

  • GetCollisionEnabled

  • GetTransform

  • GetPhysicsObjectById

  • GetAllPhysicsObjects

• Fixed non-primitive components that were ignored from the transformation process.

• Fixed the FastGeoContainer not containing any physics.

• FastGeoStreaming.ini is now DefaultFastGeoStreaming.ini.

• Root component mobility is now preserved when the FastGeo runtime cell transformer creates a new replacement root component for a transformed component.

• Fixed primitives incorrectly showing when running PIE and the player is ejected.

• Fixed a MT issue in-editor.

• Removed unused EProxyCreationState::Pending and UFastGeoComponentEditorProxy.

• Refactored to simplify/clarify the interface of the fast geometry component.

• Fixed the WorldPartitionRuntimeCellTransformerISM duplicating instances for Blueprint actors that were not fully transformable.

Multiple additional fixes for crashes, threading, deadlocks and initialization are also part of this experimental release.

World Partition Insights

We added world partition streaming debugging tools to Unreal Insights and Unreal Editor, making possible per-cell analysis and sessions playback.

HLOD UX

We made the following improvements to world partition hierarchical level of details (HLODs).

Functionality:

• Added a batched deletion operation to reduce source control overhead.

• Now supports standalone HLODs when placing multiple instances of the same sub-world partition level.

• Added a perceptual difference heuristic option to update HLODs only when needed.

• Added support for new and deleted actors when building HLODs directly from a level in the editor.

UX:

• Build HLOD for Selection.

• Build HLOD for Selected Region through the world partition editor.

Procedural Content Generation (PCG)

Manual Editing

In UE 5.8, we added non-destructive manual editing of PCG data and artifacts through selection, exclusion, modification and support for restoring data.

Individual nodes in the graphs can be marked for manual editing or temporarily overridden. A new Data Overrides window lists all overrides applied to an inspected node.

Complex Attributes

Using arrays, structures, sets, and maps as metadata attribute values and overrides are now supported. This includes various operations to extract data in structures and arrays as well as array operations.

New Create Complex Constant and Add Complex Constant nodes are available to use in PCG graphs on top of graph parameters with complex types.

Embedded Subgraphs

We added support for creating custom subgraphs, similar to Blueprint functions, stored and edited directly within a PCG graph.

Graph Parameters Editor

You can now categorize, sort, group, and describe PCG parameters in the new parameters hierarchy editor tool.

PCG Performance

Runtime:

• PCG GPU runtime scatter is now within the same performance range as the landscape GPU grass system, and was stress-tested on all platforms.

• Actor/component-less runtime generation

Editor:

• Added CRC and caching improvements when running a graph, reducing potential cache invalidation with increased efficiency.

• Improved ISM re-use logic when spawning large sets of static meshes.

• Made graph execution and scheduling improvements removing contention and bottlenecks.

PCG UX

We continue to make UX improvements when working with PCG, these are latest changes:

• Contextual filtering: When adding a new node by dragging from any typed pin, the node palette is automatically filtered to supported operations, with options to include conversions or disable filtering entirely.

• HLSL kernels: You can now create attributes directly from the HLSL kernel rather than in the node settings.

• HLSL editor: You can now set font size.

• Data viewport: You can now edit manual overrides from the PCG editor's data viewport

PCG Nodes and Operators

With Unreal Engine 5.8, we also introduce multiple native PCG elements and new options including:

• Metadata array operations: Most useful operations for arrays (make, add, add unique, contains, and more).

• Align points: Snap points position and rotation against the bounds of another point on any given axis and spatial referential.

• Scene Capture: The Scene Capture node now supports input transforms allowing captures to be taken from any direction and adding extra flexibility for GPU sampling.

• Create / Add Complex Constant: Use these nodes to create or add any complex attribute type directly in the graph.

• Apply Spline to Component: Writes the PCG spline data onto an existing Spline component reference. Useful for applying changes on existing splines in-editor.

• Teleport Actors and Components: Gives you a method to apply a transform to any actor or component reference in the world. Useful for a new level-based PCG workflow to apply an instant operation in-editor.

• Get Class from Attribute: Gets the class from a soft object reference and returns it as an attribute.

• Get Editor Cameras: Returns the current visible editor viewport cameras as points to use for various in-editor operations.

• Set Materials On Dynamic Mesh: Apply material to dynamic mesh data.

Procedural Vegetation Editor (Experimental)

The Procedural Vegetation Editor is an experimental plugin to create and edit vegetation meshes, supporting Nanite foliage, directly within Unreal Engine. With UE 5.8, we introduce some core new functionality that greatly expands the capabilities of PVE, enabling growth directly in the editor without the need for imported recipes, along with numerous other improvements.

• Growth Node

• Seed Generation

• Skeletal Extraction from 3D Mesh or 2D image/Atlas

• Foliage Grafting

• Object Avoidance and Carving

• Trimming- branch loops, displacement tessellation

• Mesher Improvements

• Visualization Modes

• Trunk Material Compositor

For more information on this feature, see Procedural Vegetation Editor.

Framework

StateTree Starting States and Compiler Extensions

State Tree gets a flexibility boost in UE 5.8.

We improved authoring workflows; trees can now define their starting state.

A new Compiler Manager helps streamline iteration, and the editor now tracks when trees are out of date so it’s clearer when a recompile is needed.

Property binding is more robust and now allows binding to be easily reversed, making it straightforward to move data from one completed task to another.

For more information on this feature, see Statetree.

Mass Framework: Faster, Modular, and Built for Scale

Mass, our data-oriented entity system, gets a major overhaul.

Mass Signals are now part of the core engine, and entities can be created off the game thread thanks to archetype-based, lock-free scheduling. A new sparse/virtual fragment system reduces memory use and allows optional fragments and tags to be added or removed without triggering costly archetype changes.

We completely overhauled Mass processor execution and dependency resolution to better take advantage of multi-core CPUs, resulting in safer and faster execution on modern hardware. This is supported by more granular scheduling and thread-safe observer notifications.

A new MassCore module further simplifies adoption by separating the core entity system from the broader MassGameplay stack.

For more information on this feature, see MassEntity.

Navigation: Per-Mesh Control Over Walkable Surfaces

Static meshes can now define their own walkable areas during navmesh generation, giving designers more control over how AI navigates the world. You can assign per-mesh area costs to static geometry—for example, marking a couch so AI prefers to walk around it instead of over it.

This is enabled per mesh through a flag and area class setting on NavCollision, with support carried through the full Recast generation pipeline.

Iris: Production-Ready Replication System

Iris is now production-ready for licensees in UE 5.8.

Alongside that milestone, we added a range of improvements that focus on stability and day-to-day usability. We improved protocol mismatch handling so clients get clearer errors when out of sync with the server, and new warnings help catch object lifecycle issues earlier. Serialization, cull distance handling, and diagnostics have all been refined, and RPC DoS detection has been re-enabled.

Iris also moves closer to the engine’s broader direction, with added support for Scene Graph integration and RemoteObjects RPC routing.

For more information on this feature, see Iris Replication System.

Mover: Improved Physics, Animation, and Networking

Mover receives a broad update across core movement, networking, animation, and ChaosMover.

Core movement modes get a wide range of fixes and improvements, including NavWalking support for Detour Crowd, better based movement for scenarios like moving platforms or rocking boats, and improved root motion and montage handling.

Layered moves can now be scheduled ahead of time for better synchronization, while rollback and prediction support have been expanded.

Networking also improves with optional Iris replication support in Network Prediction and adaptive time dilation to reduce client predict-ahead.

ChaosMover adds trajectory prediction for motion-matching workflows, deeper Chaos Visual Debugger integration, and broader support for sim-driven montages, layered moves, gameplay tags, and instant movement effects.

Together, these changes continue the architectural work toward moving Mover out of Experimental status while improving stability across movement modes, prediction, resimulation, and animation-driven workflows.

Unified Input System: Common UI and Enhanced Input

We streamlined input workflows in UE 5.8 with the unification of Enhanced Input and Common Input/UI. This simplifies cross-platform input handling, removes the need for duplicate data assets, and makes debugging more straightforward.

The update also includes a range of improvements across input handling, including more reliable event processing, better widget binding behavior, expanded virtual key support, and fixes for trigger edge cases.

New tooling, such as an Input Debugger for Enhanced Input UI and added extensibility, makes it easier to build and troubleshoot input-driven experiences.

Developer Iteration

Incremental Cooking (Beta)

Incremental Cooking continues as a beta feature for UE 5.8. Improvements to determinism further reduces the need to recook unmodified assets notably with DDC and structured data variations.

Incremental Cooking helps you to iterate faster on your target devices by reducing overall cooking time. Cook processes automatically analyze asset changes against output stored in Zen Server and only cook new updates made to your project's assets. This works across all native engine assets including Blueprints and World Partition tiles.

Zenserver as Cooked Output Store

Zenserver as Cooked Output Store is now enabled by default. This also has meaning for Zenserver Streaming being used automatically by workflows in Unreal Editor when launching the game / client on devices, and staging container files (pak / iostore) remains available and supported for non-iteration workflows. To ensure this functions with remote devices, Zenserver responds to remote requests, but only if they supply a pre-generated key for authorization. 

• Existing projects that have the use of Zen store disabled in their project settings will not use Zenserver as a cooked output store. They will need to manually change the setting in the project settings to enable it.

• For professional development use cases, projects should set LimitProcessLifetime=false in the Zen.AutoLaunch section of the DefaultEngine.ini configuration file so that Zenserver is not starting and stopping frequently. This requires consideration from automated / build processes to ensure that Zenserver continuing to run happens in a way that doesn’t interfere with automated / build processes.

• The AllowRemoteNetworkService config key has been renamed and changed to RemoteNetworkService and doesn’t accept true / false, and instead uses the following values:

  • None rejects remote requests to the local UE-launched Zenserver.

  • Unsecured accepts remote requests to the local UE-launched Zenserver if they contain an authorization key in their header that matches a UE-generated key.

  • GeneratedStaticKey is the default value.

For more information on this topic, see Zenserver as Cooked Output Store and Zenserver Streaming.

Horde - Performance Reporting (Experimental)

Improvements to Horde Analytics tooling continues in UE 5.8 as an Experimental feature with improvements to dashboard UX for job steps (CPU, memory usage) and job health observability.

We've also introduced a new view in Horde which shows runtime trends outputted from the Automated Performance Tests framework (APT) and the Perf Report Tool (csvprofilers), highlighting key metrics such as GPU/CPU times, peak memory usage and hitch reports so regressions can be spotted. This currently relies on users having their own database store model.

Audio

Audio Insights (Production Ready)

Audio Insights received a big update with new features and improvements in UE 5.8, expanding its diagnostic capabilities across loudness metering, signal flow visualization, live event monitoring, and data plotting — alongside numerous stability, UX, and standalone app improvements.

• Loudness Metering: A dedicated loudness meter tracks momentary, short-term, and integrated loudness values along with loudness range and true peak values, target max values and clipping indicators, processed on the engine and streamed into both the editor and standalone app.

• Signal Flow Visualizer: A new tab that traces the instantaneous audio signal graph from its source through submixes to the output device, displaying mixing values at each stage to find attenuation or routing issues. Displays cached data as well for offline forensic analysis.

• Timeline Cache Controls: Dynamic controls over display playhead synchronizing data display for a single timestamp across several dashboards of data.

• Control Bus and Modulation Visibility: The Control Bus tab now surfaces Control Bus Mixes as sources alongside individual buses, and the Modulation tab filters down to only active control bus columns to reduce noise.

• Live Monitoring: Audio Insights can now display trace data in real-time without saving a trace file, eliminating disk space concerns during long monitoring sessions. Both editor and standalone versions (via Unreal Insights) are supported.

• Event Log: A new dockable Events tab provides a live, scrollable chronological log of sound start, stop, and other audio events. Events are text-filterable, time-selectable to sync other visualizations, and double-clickable to navigate directly to the corresponding instance in the Sounds tab.

• Plots: A dedicated Plots tab consolidates per-sound parameter plotting with improved rendering, corrected color continuity across trace pauses, and fixed display artifacts in standalone.

• Standalone and Cache Improvements: The data cache manager now works in standalone sessions, trace data can be saved to a file directly from dashboard caches, and the cache size is now user-configurable via settings.

For more information on this feature, see Audio Insights.

Audio Subtitles (Beta)

Audio subtitles are required for accessibility – dialogue systems, closed captioning, and voice chat. We promoted the plugin from Experimental to Beta status, reflecting its increased stability and feature completeness.

• Subtitles now display correctly for all sound types triggered within a MetaSound graph, including nested MetaSounds.

• Per-platform subtitle display overrides are now supported, allowing different widget placement and styling for platforms such as mobile or Nintendo Switch where screen layout differs.

• Subtitles in a Level Sequence can now be previewed directly in the editor without entering Play In Editor (PIE), making iteration on subtitle timing faster.

• Subtitle duration can now be overridden per locale, automatically using the duration of the locale-specific sound wave when a localized asset is present.

• A new QueueSingleSubtitle Blueprint and C++ function replaces the older QueueSubtitle (now deprecated). A companion function, QueueSubtitlesFromAsset, queues all subtitle lines stored in an asset in a single call with correct timing offsets applied automatically.

• We added a Comment field to subtitle assets for internal notes visible in the editor but not shown at runtime.

• Various UX improvements and bugfixes.

Waveform Editor (Beta)

Sound designers need powerful editing tools without leaving the engine. We are continuing to improve the Waveform Editor with deeper control over fades and workflow refinements to reduce round-trips to external audio tools.

• Fades are now decoupled from trim. A new Fade transformation allows any number of independent fade regions — each with their own fade-in and fade-out — to be placed anywhere on the waveform, completely independent of the TrimFade region. Trim fade-in and fade-out curve types can also now be set directly from the toolbar, with right-click context menus on fade handles providing additional curve shape options. Scrolling on a fade handle adjusts the curve slope.

• Reimport is now available from the editor toolbar, with three modes: reimport and overwrite transformations (including marker and loop region data from cue and smpl chunks), reimport keeping existing transformations, or reimport from a new file entirely.

• A new Launch Transformations setting helps you pre-configure which transformations are automatically applied when opening a SoundWave that has none. This removes repetitive setup steps for standard editing workflows.

• When transformation changes are applied, the SoundWave's LUFS and Sample Peak metadata now update automatically to reflect the transformed waveform, keeping asset metadata accurate without requiring a manual refresh.

• Additional keyboard shortcuts for marker navigation:

  • G skips the playhead to the next marker.

  • F/B selects the next/previous loop marker.

  • H snaps the playhead to the nearest zero crossing.

  • Enter stops playback and rewinds to the start.

  • Shift+Space resets the playhead to the beginning of the file without affecting playback state.

• Many other usability, UX and UI improvements.

To get started with this feature, see Waveform Editor Quick Start.

MetaSound Node Configuration (Experimental)

MetaSound Node Configuration, introduced in UE 5.7, is now expanded in UE 5.8 with new tools that reduce boilerplate for developers and improve the editing experience for designers.

• Dynamic Interface Node Configuration: A new built-in FMetaSoundDynamicInterfaceNodeConfiguration struct automatically manages sub-interface instance counts and variant type selection based on a node's FClassInterface definition. Developers no longer need to write custom per-node configuration structs for the common case of exposing sub-interface counts or variant pin types — the Details panel now surfaces these controls automatically as dropdowns and count fields.

• Node Update Transform API: A new, more structured API for authoring node update scripts gives developers fine-grained control over how nodes migrate when their interface changes across major versions. Custom update logic is now associated with a specific major version and runs after minor-version and interface updates have been applied, ensuring predictable ordering. An example migration — updating the biquad filter's default bandwidth from 1.0 to 2.0 for newly-placed nodes while preserving the legacy default for existing content — demonstrates the pattern.

• Sub-Interface Layout Serialization: Sub-interface layout information is now correctly reconstituted when deserializing MetaSounds, resolving cases where vertex name collisions and layout loss occurred on certain platforms.

• API Stability: FClassInterface exits its experimental designation in UE 5.8. FNodeClassMetadata::DefaultInterface now accepts FClassInterface directly (replacing FVertexInterface), and deprecated input/output node creation helpers have been removed from IDataTypeRegistry. Developers building Node Configuration integrations can treat this as the stable public API surface going forward.

MetaSound Templates (Experimental)

MetaSound Templates is a new Experimental feature in UE 5.8 that gives audio programmers the means to create reusable, property-driven MetaSound generation logic that sound designers can use enabling rapid iteration without ever having to touch the graph.

• A Template is a C++ defined UStruct that can procedurally configure and rebuild a MetaSound graph, its interface, and inputs any time a designer changes one of its exposed properties. 

  • Templates can limit what Designers see to only the properties the template author chose to expose; the underlying graph, member list, page options, and more, can optionally be hidden entirely.

  • The programmer defines a small set of parameters they want designers to control — a list of sounds, a pitch range, a filter cutoff — and the Template's code handles configuring the given options into a valid MetaSound graph.

• From the MetaSound Editor, designers select a template from the new Template toolbar dropdown and edit its properties in the MetaSound Details panel.

  • Converting a templated MetaSound back to a standard one (preserving the last generated graph state) is also supported.

  • A template can also ship a fully custom UMG widget tab built on Unreal's MVVM framework, providing a purpose-built interface — sliders, previews, array editors — instead of or alongside the default MetaSound panels.

• A Randomizer template ships with UE 5.8 as a reference implementation. It picks randomly from a designer-specified list of Sound Waves, applies a pitch offset within a configurable semitone range, and supports both one-shot and looping playback modes. It is hidden by default in UE 5.8, but serves as a working code example for template authors.

Format / Channel Agnostic Types (CAT) (Experimental)

• Full Pipeline Integration: CAT output is now wired through MetaSoundSource meaning a MetaSound graph can produce a CAT signal and deliver it directly to the audio engine. The channel format can be automatically determined by looking at the sound waves set on the MetaSoundSource inputs.

• Data-Defined Audio Formats: Custom channel configurations can now be declared as first-class audio formats and used directly within graphs. This enables teams to define and work with non-standard or proprietary speaker layouts without forking engine code.

• Ambisonics and Transcoding: First-order Ambisonics is now a built-in CAT format. Transcoding between Discrete and Ambisonics formats is handled automatically at graph boundaries, so spatial audio workflows no longer require manual conversion nodes.

New Nodes for Experimentation

• Wave Player 2.0: A next-generation wave player reimplemented on top of the CAT foundation utilizing experimental sound asset container.

• CAT Mixer: A dedicated mixing node for combining multichannel CAT signals within a graph

• Grain Player: A grain synthesis playback node built on the CAT pipeline

• Multiply: The Multiply node gains new CAT-aware variants:

  • CAT × float

  • CAT × CAT

  Multichannel signals can now be scaled and modulated without collapsing to mono first, enabling per-channel gain, ring modulation, and envelope shaping directly on multichannel buses.

• Ladder Filter: We ported the Ladder Filter to process both standard AudioBuffer and CAT signals. The existing mono filter path is preserved; the CAT path handles multichannel audio with independent per-channel filtering. This conversion also serves as the reference implementation for porting additional MetaSound DSP nodes to CAT.

Audio in Sequencer

Sound designers using Sequencer for cinematics, gameplay sequences, and rendering frequently hit friction around audio mixing control, default behaviors that don't match expectations, and audio quality issues in exported renders. In UE 5.8 we are shipping a significant set of improvements across three areas.

Control Bus and Control Bus Mix Tracks

• Two new Sequencer tracks bring Audio Modulation directly into the timeline.

  • The Control Bus Track makes it possible for any Audio Modulation Control Bus — volume, pitch, filter cutoff, or any custom modulation parameter — to be keyframed and animated over time within a sequence.

  • The Control Bus Mix Track provides a way to activate and deactivate a pre-defined Control Bus Mix (a set of modulation values applied together) at specific points in the sequence, enabling precise and repeatable audio mix states tied to cinematic events.

Playback and Section Behavior Improvements

• We redefined Audio section looping behavior to align more closely with typical sound designer intent; users define if a sound will play to completion rather than reusing concepts of KeepState or RestoreState when the section is finished, and Looping was renamed as Repeating to distinguish between section on game frame boundaries and asset looping on sample boundaries.

• Audio sections no longer auto-expand when keyframes are added outside their bounds.

• MetaSound integration enables more reliable playback of MetaSound sources.

• The audio evaluation system has been improved to avoid unnecessary stop-and-restart when the playhead context jumps, resulting in smoother scrubbing and pause/resume behavior.

Movie Render Queue Audio Improvements

• MRQ now supports expanded submix selection for audio export, giving you direct control over which submix is recorded rather than being limited to the default output.

• We fixed audio popping, gaps, and repeats that previously occurred at camera cut boundaries; the audio component is now paused and resumed across cuts rather than stopped and restarted, eliminating sample-level discontinuities in rendered output.

WASAPI

In Unreal Engine 5.8, we switched the default audio backend on Windows from XAudio2 to WASAPI. The new AudioMixerWasapi module is now selected automatically; XAudio2 remains available as an opt-in fallback. The same backend is also used on Xbox. No changes are required on the developers end. All content should behave the same — only the layer that talks to the operating system has changed.

Why we made the switch:

• Future-proofing. Building on a supported, actively-maintained Windows API instead of a legacy one.

• Better latency capabilities. Direct access to the lower-level API gives the audio mixer more control over buffer scheduling.

• More robust device handling. The WASAPI backend now includes full device-swap support — plugging or unplugging headphones, switching the Windows default device, or having audio drivers force a device change is handled cleanly by the engine.

• Quality and reliability improvements. Over the course of the 5.8 cycle, the audio team hardened the backend against a long list of real-world device-change, format-negotiation, and shutdown edge cases discovered in production. The result is a more stable Windows audio path out of the box.

What you should know:

• This is a Module, not a plugin. WASAPI ships as the AudioMixerWasapi module inside the engine. There's nothing to enable or install.

• Device swap is supported. Headset connect/disconnect, default-device changes, and sample-rate changes are all handled by the backend.

• Opting out (fallback to XAudio2). If you hit a project-specific issue, you can revert to the previous backend by adding the following to your project's Config/Windows/WindowsEngine.ini:

  Config

  [Audio]
  AudioMixerModuleName=AudioMixerXAudio2

  Copy full snippet(2 lines long)

  We recommend reporting any issue you encounter so it can be addressed before XAudio2 is eventually removed.

Platform

Mobile Renderer

With Unreal Engine 5.8, we advance the mobile renderer and expand access to higher-quality rendering features on supported devices.

UE 5.8 delivers:

• Multi-pass deferred rendering as the default path across mobile platforms (with forward rendering still available as an opt-in).

• Broader use of GBuffer and depth data.

• Mobile support for SSAO, SSR, deferred decals, contact shadows, and higher-quality water rendering.

In UE 5.8 we also introduce half-precision (FP16) shader usage in targeted materials and global shader passes, improving performance while preserving visual quality.

Together, these changes raise visual fidelity and scalability on high-end mobile hardware while preserving performance and giving teams more headroom to tune quality levels.

Android Platform Support

With Unreal Engine 5.8, we deliver targeted Android platform improvements focused on input support and iteration speed.

UE 5.8 delivers:

• Improved controller mapping support.

• Simpler automated setup of developer workstations using Turnkey.

These changes improve developer productivity and platform robustness for teams building and testing Android projects.

Preview Platform

In Unreal Engine 5.8, we improve the visual fidelity of the Preview Platform feature so visuals displayed in the Editor more closely match the look and behavior of target hardware.

Teams can catch visual issues earlier and reduce the cost of switching to device for iteration.

For more information on this feature, see Using Preview Platform

Keyboard and Mouse Support for iOS and iPadOS

In Unreal Engine 5.8, we add full keyboard and mouse support for iOS and iPadOS, giving creators and players a way to interact with projects using standard desktop input devices. This brings input behavior on iPad and iOS closer to macOS parity, improving usability for development, testing, and gameplay scenarios where keyboard and mouse are expected.

Projects running on iOS and iPadOS can now be interacted with in a consistent, desktop-like way when appropriate, reducing platform-specific friction when targeting Apple ecosystems.

Gesture Events for iOS and Android (Experimental)

With Unreal Engine 5.8, we introduce an experimental gesture event system that bridges to the native gesture recognizers on iOS and Android and surfaces their events directly to the engine. Pinch, swipe, rotate, and pan are recognized with the same accuracy, timing, and began/changed/ended state transitions that native apps get, removing per-platform touch-handling code and giving developers a consistent way to drive touch-based interactions across mobile.

iOS Application Extensions

In Unreal Engine 5.8, we add first-class support for iOS App Extensions through a new .uappex control file. Project authors can now declare extensions such as Notification Service or Background Assets alongside their UE project, and UnrealBuildTool generates the corresponding Xcode App Extension target automatically — no manual post-generation Xcode editing required.

Unreal Engine Remote

Unreal Engine Remote is a companion app that lets developers preview and test mobile input without building or deploying to a physical device. 5.8 expands the app to Android (previously iOS-only) and switches the streaming backend to Pixel Streaming 2, so a live Play in Editor session from UE5 or a Mobile Preview session from Unreal Editor for Fortnite can be streamed to a mobile device — mirroring the in-game experience on device and reporting touch and gesture inputs back in real time.

This means teams can:

• Validate mobile input behavior directly from a preview session.

• Iterate on touch controls without a full device build.

• Test across both UE5 and UEFN workflows using the same app, on both iOS and Android.

UE Remote shortens the mobile development loop, giving developers a fast, accurate impression of how input feels on mobile hardware without the cost of repeated on-device deployments.

For more information on this feature, see Using Unreal Engine Remote with Remote Session.

Steam Frame Support (Experimental)

Together with Valve we have implemented experimental support for their next XR platform: https://store.steampowered.com/sale/steamframe

bPackageForOpenXRImmersive is a new setting that defaults to true in the VR Template.

Stereo Layer Underlays

In UE 5.8, OpenXR stereo layers can now be drawn behind the main scene. This opens up XR effects that used to require engine modifications or vendor-specific plugins.

Before UE 5.8, Unreal Engine's OpenXR support always drew stereo layers on top of the projection layer (the rendered UE world), and face-locked layers always sat above world-locked ones. That fixed order made true "underlays" — layers that appear behind the environment — impossible out of the box, even though the OpenXR spec itself just takes an ordered list of layers with no such rule.

This change replaces the fixed order with one driven by layer priority, matching how OpenXR works. It adds two new settings:

• xr.OpenXRProjectionLayerPriority (default = 0). The priority of the projection layer. Any stereo layer with a lower priority is drawn behind it; anything higher is drawn in front, as before.

• xr.OpenXRSortFaceLockedLayersAboveOtherLayers (off by default) — when on, face-locked layers always draw above everything else, regardless of priority. This matches the old behavior.

To restore the pre-UE 5.8 order, set xr.OpenXRSortFaceLockedLayersAboveOtherLayers=1 and set xr.OpenXRProjectionLayerPriority to a value lower than every stereo layer priority in your project (for example, -2147483648, the minimum 32-bit integer). Existing projects keep working with no changes.

GitHub changelist for details (connected account required): https://github.com/EpicGames/UnrealEngine/commit/83641b6ac8b243d9858f54bafe1937f0accb4b6f

For more information on this feature, see OpenXR Stereo Layers.

PICO Controller OpenXR Plugin

The PICO Controller plugin adds support for PICO's OpenXR interaction profiles XR_BD_controller_interaction and XR_BD_ultra_controller_interaction.

The plugin is enabled by default in the VR Template and PICO controller bindings have been configured for the Input Mapping Contexts.

iOS Shader Model 6 (Experimental)

In Unreal Engine 5.8, we add experimental Shader Model 6 (SM6) support on iOS, integrating Apple's Metal Shader Converter library to unlock advanced GPU features on Apple Silicon.

UE 5.8 delivers:

• A dedicated iOS SM6 shader platform variant alongside the existing Metal paths

• Wave intrinsics (SIMD-group operations) for more efficient GPU compute algorithms

• Native 16-bit (FP16) shader types to improve ALU throughput on Apple Silicon

Support targets A15 and newer Apple Silicon and ships as experimental, with the existing Metal rendering paths preserved for broader device coverage. Validation of SM6-gated rendering features such as improved deferred techniques and higher-quality compute paths is underway and will land in subsequent releases.

Content Pipeline

UI rework - Interchange Import Dialog UI

The Interchange Framework is highly customizable and subsequently the window dialogs to configure Interchange and to import data are overwhelming with options.

The goal of the upcoming releases is to simplify the UI. In UE 5.8, we regrouped and renamed all options related to asset type conversion for better clarity, while material import options have clearer control of creation of material versus use of existing materials. 

For more information on this feature, see Interchange Framework.

FBX Import Performance

While glTF and USD usage intensifies, FBX remains the main data format to import 3D models in Unreal Engine. This is why we introduced an alternative library to improve user experience with this format.

In UE 5.8, we performed stabilization work to support for the uFBX library (Experimental); it noticeably reduces import import times especially on heavy .fbx files containing large meshes. Users with multi -cores CPUs will also notice improvement for files with a large number of meshes.

In alignment with USD, Unreal will now preserve nodes visibility from .fbx files, when importing into level, and apply it on the "hidden in game" property.

USD Asset Pre-Generation

USD scenes are often composed recursively from multiple referenced USD files. The current USD Interchange import workflow processes these compositions in isolation, resulting in flattened imports and unnecessary duplication of asset data.

The new USD Pregen framework introduces a robust system for discovering, tracking, and persisting relationships between referenced USD assets and their corresponding Unreal Engine representations.

This feature is experimental in UE 5.8. The key benefits are:

• Reduced asset duplication

• Composition- and asset-aware processing

• Granular processing

• Configurable framework

USD Import with Interchange

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

We added USD to the list of file formats supported by the Interchange framework in 5.5. Content creators benefit from more control over the import process and can now 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.

In UE 5.8, the support for USD through Interchange is considered production ready for asset import and experimental for level import. We added support for:

• Ordering of schema handlers; the ordered list of schema handlers used when loading a USD file is exposed and editable.

• Support for custom schema translator; USD translator can be extended in code to support custom schemas.

• A mechanism to add new render context.

• A Nanite build settings schema.

• All groom attributes.

• Collapsing (parity with legacy USD import).

• Chaos Cloth.

Editor

Editor Gizmo System

With Unreal Engine 5.8, we introduce a new Editor Gizmo System designed to deliver a more consistent and flexible interaction experience across the editor. Built on top of the Interactive Tools Framework, the new system consolidates multiple legacy gizmo implementations into a single framework used across viewports and tools. This unification improves reliability, interaction consistency, and extensibility for developers building tools within the editor.

The redesigned gizmos also include a range of visual and usability improvements inspired by workflows familiar to artists and level designers from tools like Maya and Blender. With improved hit targets, clearer visual feedback, customizable interaction presets, and enhanced precision controls, the new system provides a faster and more predictable workflow for manipulating actors and assets.

For more information on this feature, see Transforming Actors.

Visual and Interaction Improvements

• Refined Gizmo Design: Thinner visual profile with improved hit targets for more accurate selection and interaction.

• Improved Hover and Interaction Feedback: Clear highlighting when hovering or interacting with axes and planes.

• Planar Handles Repositioned: Planar movement axes are positioned further from the center, improving accessibility and reducing accidental selections.

• Expanded Screen-Space Movement Handle: Larger center movement square for easier screen-space translations.

• Axis Visibility Improvements: Axes temporarily hide during interaction to improve visual clarity.

• Improved Scaling Behavior: Gizmos now operate more reliably from all viewing angles, enabling more predictable scaling interactions.

Precision & Movement Feedback

• Numeric Delta Overlays: Real-time overlays display movement, rotation, or scale deltas during interaction.

• Delta Line Indicators: Visual lines indicate how far an object has been translated from its original position.

• Rotation Delta Line: Rotation interactions display a visual delta line similar to Blender, improving precision when rotating from greater distances.

Snapping & Interaction Enhancements

• Snapping State Indicator: The gizmo center icon now visually indicates when snapping is enabled.

• Temporary Snapping Controls: Quickly toggle position, rotation, scale, or surface snapping while holding a modifier key.

• Viewport Boundary Interaction: Continue manipulating actors even when the cursor moves outside the viewport bounds.

Customization and Workflow Presets

• Interaction Presets: Choose from multiple interaction styles:

  • Default Unreal Engine interaction

  • Classic Unreal interaction

  • Maya-style interaction

• Customizable Gizmo Behavior: Increased flexibility for teams to configure interactions based on their preferred workflow.

Precision Controls

• Precision Mode: Temporarily slow down transformations for fine adjustments.

• Nudge Mode: Incrementally adjust translation, rotation, or scale for controlled edits.

Preview Scene Improvements

With Unreal Engine 5.8, we expand the Preview Scene system with new customization and workflow improvements for asset editors. These updates give users greater control over how assets are presented during preview, making it easier to evaluate materials, meshes, and lighting conditions directly within the editor.

Customization Enhancements

• Custom Floor Mesh Support: Configure a custom floor mesh in preview scenes to better match the environment where assets will be used.

• Custom Floor Material: Apply custom materials to the preview floor for improved context when reviewing assets.

Workflow Improvements

• Layout Improvements: Profile management has been moved to the top of the Tab for easier access.

• Preview Profile Cycling : Quickly cycle between Advanced Preview Scene profiles using a keyboard shortcut, giving users a way to rapidly switch between lighting and environment setups when evaluating assets.

Material Preview Editor Improvements

With Unreal Engine 5.8, we introduce several improvements to the Material Preview Editor to support faster look development and more flexible preview workflows. These updates make it easier to evaluate materials using familiar preview meshes and quickly test assets directly within the preview environment.

Preview Enhancements

• Shader Ball Preview Mesh: A shader ball is now available as a native preview mesh option, giving you a familiar surface for evaluating materials and lighting response.

Workflow Improvements

• Drag-and-Drop Asset Support: You can now drag and drop assets directly from the Content Browser into the preview window, allowing for faster testing of meshes and materials.

• Material Slot on Custom Mesh: The material can now be applied to specific slot(s) when a custom preview mesh has been selected.

Shortcut Manager

With Unreal Engine 5.8, we introduce a refreshed Shortcut Manager experience, making it faster and easier to discover, manage, and customize editor keybindings. The updated interface provides improved search capabilities, clearer presentation of commands, and streamlined tools for managing shortcut configurations.

With a modernized UI that aligns with Unreal Engine’s current editor styling and enhanced search tools for quickly locating mapped or unmapped commands, the updated Shortcut Manager helps developers and artists tailor their workflows more efficiently.

Interface and Usability Improvements

• Visual UI Refresh: Updated interface styled to match the modern Unreal Editor dark theme.

• Dedicated Window: Keyboard Shortcuts now have a dedicated window with a more compact layout.

• Cleaner Layout: Reduced inline tooltip text for improved readability and clearer command descriptions.

• Focused Shortcut Search: Search is now scoped specifically to keyboard shortcuts, making it easier to find commands by action or command name without unrelated results.

Enhanced Search and Discovery

• Shortcut Key Search: Quickly find commands mapped to a specific key combination (for example, searching for Ctrl + S displays all commands bound to that shortcut).

• Keybind Search Button: A dedicated option to search directly by pressing a key combination to reveal all mapped commands.

• Advanced Search Syntax: Filter results to locate specific states such as unbound commands, helping identify opportunities to customize workflows.

Configuration and Workflow

• Improved Import and Export: Streamlined tools for sharing and transferring shortcut configurations across machines or teams.

• Faster Keybinding Management: Improved discoverability of commands and bindings to help users quickly customize their editor experience.

Editor Preferences Improvements

With Unreal Engine 5.8, we introduce updates to the Editor Preferences system to improve consistency, discoverability, and ease of use. Editor Preferences, Project Settings, and plugin settings now share a more unified visual style and layout, making configuration across the editor easier to navigate.

Additional improvements to search, keyboard shortcuts, and reset functionality make it faster for you to find and manage the settings they need.

Interface and Navigation Improvements

• Unified Settings Styling: Editor Preferences, Project Settings, and plugin settings now share a consistent visual design and layout.

• Default All Settings View: Settings now open with the All Settings category selected by default for easier discovery.

• Category-Scoped Search: Users can search within a specific category by selecting it, making it easier to narrow down results.

Search and Discovery Enhancements

• CVar Visibility in Search: Easily identify when a preference is controlled or influenced by a console variable (CVar).

Workflow Improvements

• Keyboard Shortcut Access: Quickly open Editor Preferences, Project Settings, and Keyboard Shortcuts using dedicated hotkeys.

• Reset to Default: Most settings can now be easily reset to their default values, simplifying experimentation and recovery from configuration changes.

Orthographic Viewport Improvements

With Unreal Engine 5.8, we introduce several improvements to Orthographic Viewports aimed at improving clarity and usability when working in top, side, and front views. These updates reduce visual noise and ensure important editing tools remain clearly visible during interaction.

For more information on this feature, see Orthographic Camera.

Visual Clarity Improvements

• Improved Lit View Rendering: Reduced interference from atmospheric fog in orthographic views, resulting in clearer and more predictable lighting results.

• Reduced Grid Density: The orthographic grid has been scaled to reduce visual noise and clutter, improving scene readability.

Interaction Improvements

• Gizmos Render on Top: Transformation gizmos now render above selected objects, ensuring they remain visible and easy to interact with during editing.

Content Browser Right-Click Menu

In Unreal Engine 5.8, we include a simplification of the Content Browser right-click menu aimed at reducing friction in the asset creation workflow. This effort focuses on reducing menu height, organizing asset types more logically, and making commonly used assets easier to find, resulting in a cleaner and more streamlined right-click menu experience.

Menu Organization Improvements

• Fewer Top-Level Categories: Reduced the number of categories in the right-click menu to minimize height and make the menu easier to scan.

• New Audio and Animation Subcategories: Added dedicated subcategories for Audio and Animation to better organize asset types and avoid overly long lists.

• New Data Section: Introduced a Data category to make data-oriented assets easier to identify and access.

Asset Discovery Improvements

• Material Instances in Common Section: Added Material Instances to the Common section so one of the most frequently used asset types is quicker to access.

Details Panel Favorites

In Unreal Engine 5.8, we expand the Details Panel Favorites system to make navigating and tracking important properties faster and easier. These updates help users quickly locate commonly used settings and identify modified properties within complex actors and assets.

Favorites Enhancements

• Favorite Full Categories: Users can now favorite entire property categories, making it easier to access groups of commonly used settings without favoriting individual properties.

Visual Feedback Improvements

• Category Section Filter Bar: The section bar can now optionally filter the details panel to favorite categories or modified properties.  You can enable these in the Details panel settings dropdown.

Workflow Benefits

• Faster Property Navigation: These improvements make it easier to locate frequently used settings and quickly identify what properties have been modified within the Details Panel.

MCP Server (Experimental)

With Unreal Engine 5.8, we bring a new experimental MCP (Model Context Protocol) plugin for the Unreal Editor. This plugin enables agentic AI systems to connect to the Unreal Editor. This allows these systems to understand the engine and the project, as well as helping users build assets or systems.

For more information on this feature, see Unreal MCP.

Sandboxes

Sandboxes provide an isolated workspace where you can experiment without affecting the main project. Open a sandbox, create and edit freely, and persist only what you want to keep

You no longer need to spin up a side branch, copy assets to a WIP folder, or worry about polluting your revision control just because you want to try something out.

• Create a sandbox and work inside it without affecting the project content Browse, switch, and see changes in sandboxes from a dedicated browser

• Persist only the changes you want to keep in your project

• Export a sandbox to share with a teammate, or import one to pick up where they left off

Production Rendering Pipeline

Movie Render Graph (Production Ready)

Movie Render Graph enters Production Ready status for the UE 5.8 release.

Graph-based configurations now support all major features found in legacy presets. Users can continue to use preset-based configurations but going forward, new features will be graph-only.

For more information on using this feature, see Movie Render Graph. 

Light Modifier

With an eye toward post-compositing workflows, the Light Modifier enables artists to set and override property values for light actors on a per-render layer basis in Movie Render Graph. Using the same level and level sequence, artists can isolate individual lights or groups of lights and render shots with different values for intensity, color, and/or any custom property on any type of light.

A new Light Actor Type Condition on the Collection node makes grouping lights for per-render layer modification easy and convenient. Properties can also be made into graph variables and exposed as overrides in both the Quick Render and the Movie Render Queue windows.

Accumulation Depth of Field

Real-time performance considerations for depth of field rendering can limit visual quality on shots that emphasize it in their design. In order to achieve more “filmic” depth of field, artists must move to the Path Tracer, which has a higher cost in rendering time, and do so for all shots for consistency, even the ones that don’t rely on depth of field. Ideally, there could be an option to have the best of both worlds in terms of performance and quality.

Accumulation Depth of Field is a new feature that renders depth of field by accumulating deferred renders from multiple aperture view points using Movie Render Graph. This greatly mitigates artifacts due to missing parallax while preserving deferred rendering look development. Artists can use it when they don’t get the desired visual results with the default depth of field and avoid the cost on shots that don’t need it. 

nDisplay Rendering in Graph

While nDisplay deployments can (and most often do) run live and in real-time, the ability to render a cluster using Movie Render Queue can be very useful for use cases such as prerendered playback and WIP content review. In the UE 5.8 release, we integrate nDisplay with Movie Render Graph to provide better support for scalable rendering setups. The UE 5.8 feature set includes:

• Support for collections, modifiers, and render layers.

• Support for both the deferred renderer and path tracer.

• Control over the DCRA in Sequencer or using an override in the graph config.

• Built-in file naming tokens for nDisplay concepts like DCRA, Node, Viewport, and more.

• Support for stereo rendering.

ICVFX Camera support will come in a future release.

For more information on using this feature, see nDisplay Overview .

New Queue Window - Basic Config

With Unreal Engine 5.8, we introduce a new, streamlined Queue window with a basic configuration that offers common properties such as name, resolution, and location for single-layer renders directly in the panel. Artists can choose between the deferred renderer and the path tracer, and change the output type without having to open another window or saving an asset.

Default values can be customized and saved so the queue always opens with the correct and desired settings. The current state of the basic configuration can also be saved out as a graph configuration to use as a starting point for more complex render setups.

Virtual Production

Mocap Manager (Beta)

For Unreal Engine 5.8, we improved Mocap Manager in the following ways:

• Auto-cameras: Spawn and control procedural cameras that follow and frame the action dynamically.

• User extensibility: Users can now create their own custom workflow UIs.

• Dedicated face animation preview: Quickly check facial animation without needing to move the viewport camera.

• Improved Retarget tuning.

• Capture manager video ingest support: Mocap Manager can now pipeline your facial animation videos with the rest of your performance capture session data.

• Audio recording configurability: Parity with Take Recorder to define audio device and channel selection per recording track.

• Live Link Hub device integration: Control Hub recording from Mocap Manager.

Composure (Beta)

The new Composure enters Beta status for the UE 5.8 release. Numerous improvements for both live and post-vis scenarios are now available, including:

• Full Sequencer support (including spawnables) for composite actors and referenced camera actors.

• Lightweight planar reflections and single light shadow layers as faster performance options.

• Passes can now be configured on any and all Layers (beyond just plate layers) and there are several new and improved passes:

  • Blur

  • Dilation

  • Masking

  • Post Process Material

  • Transform.

  • Translucency

• Composure panel UX improvements:

  • Sync selection of actors.

  • Manage composite mesh materials.

  • Assign specific components as composite meshes and/or shadow/reflection catcher content.

  • Start media capture directly from Composure.

  • Convenience option to create a skysphere actor with the current plate.

• Color grading: Pass integration with the editor's Color Grading panel.

Composure Keyer

A high quality key is a foundational feature of any compositing toolset and in the UE 5.8 release build, we expanded Composure's options in several key areas:

• See a preview of the media texture when picking a key color without having to context switch within the editor.

• Acquire a clean plate texture from a live feed with a single-click in the Composure panel, conveniently save it as an asset, and automatically set it in the composite actor.

• Use a Luma keyer pass instead of or in addition to the color keyer pass.

• Use Ultimatte with Composure via a tailored pass that configures the rendering pipeline to ensure correct color accuracy.

• Use the new dilation pass  to tune edges.

Visualize Alpha in Viewport

Inspect the Red, Green, Blue, or Alpha channel directly in the editor with a new viewport visualization option. The Channels menu provides additional options for pinning it to the viewport menu for quicker access and visualizing alpha as a checkerboard.

nDisplay Auto Exposure

Unreal Engine projects often use Auto Exposure, which samples the scene buffer and computes the average brightness histogram for dynamic EV adjustment. Up until now, nDisplay required manual EV to ensure continuity across viewports. In UE 5.8, we introduce support for Auto Exposure in nDisplay.

Metering can use the entire nDisplay DCRA or specific nodes or viewports that apply to the rest of the cluster. You can also exclude items from Auto Exposure.

Rivermax on Linux

The Nvidia Rivermax plugin in the UE 5.8 release now supports the Linux operating system in addition to Windows with validated functionality for nDisplay for ICVFX.

Live Link Hub - Device Framework

For teams requiring use of multiple recording devices during a performance capture session, Live Link Hub now offers a device framework to control devices over IP across your mocap studio. You can now monitor all your Live Link data, UE editor clients and control recording devices in one place.

Live Link Hub ships with a wide selection of devices:

• Live Link Face for iOS and Android

• AJA video decks

• Sound Devices audio recorder

• OBS screen recorder

Third-party motion capture hardware and software suppliers like Optitrack and Vicon will be shipping updates to their plugins for the UE 5.8 release.

Your Unreal Engine clients, running Mocap Manager or Take Recorder, can push slate name and take number to Live Link Hub and all the connected devices as well as control recording start and stop. Input your required slate and take in one location and keep it consistent across your whole mocap studio.

Live Link Hub - Timecode and Timestep Control

Using Live Link Hub's media profile, users can now remotely set the timecode and timestep of all connected UE clients, maintaining recorded data consistency across your performance capture stage setup and projects.

• Live Link timecode and system timecode providers are supported.

• Timecode custom timestep and Live Link custom timestep are supported.

Live Link Hub - Video Monitoring

Live Link Hub now uses UE's media profile to view and control video data for use in animation solving and reference monitoring. Using a new RTSP media source, as well as existing AJA, BlackMagic and NDI media sources, users can monitor multiple video sources during performance capture sessions including streaming from the Live Link Face app on Android and iOS.

The MetaHuman video Live Link source can now use video sources from the media profile as facial animation data, opening up a wide range of cameras and capture devices for use in facial capture.

Editor Utility Naming Tokens

Users can now create editor utility naming tokens, which have access to editor functionality previously unavailable to runtime naming tokens.

• Call editor utility functions directly inside a naming token Blueprint.

• Execute Python nodes when evaluating a token and retrieve your token values from your database or external processes.

Integrated Timeline Template Editor in CAT Schemas

You can now author timeline templates directly from the schema editor. Cinematic artists no longer need to hand-build the same sequence layout over and over again. Schemas can be referenced as subsequences within future schema timelines, giving you the ability to create nested hierarchies of reusable templates for camera, FX, lighting, and more.

• Design a schema template once and reuse it across every assembly.

• Create the template structure visually in the schema editor without leaving the Cinematic Assembly tools.

• Specify tracks, folders, spawnables, and subsequences that should be included in every assembly created from the schema.

• Nest schemas as subsequences in order to create a complex hierarchy in manageable chunks.

Reference and Parent to Spawnables During Take Records

Actors can now maintain references to spawnables through take records. Actors parented under spawnables will stay parented throughout the record and will be correctly recorded with attach tracks in the result. You no longer need to rely solely on possesables or create custom tools to replace references to spawnables when they break at the start of recording.

• Reference spawnables safely throughout setup and record.

• Re-record the same actor to spawnable without overwriting.

• Use the world outliner to parent to a spawnable and maintain that parenting across recording.

VCam Attach Browser and Constraints

The virtual camera now has a dedicated browser for parenting and platforming.

• Browse all attachable actors and components from inside the VCam UI.

• Attach and detach the camera to/from a target without leaving VCam.

• Filter by key actor types or only actors close to you.

VCam Per-Axis Attachment

VCam now attaches to its parents through animation constraints, giving you the ability to choose which axes to inherit or ignore for more fine-tuned control.Composure Panel UX improvemecle

Media

Tiled Mipmap Video (Experimental)

With the addition of tiles and mips support to EXR playback, we made it possible to achieve high resolution playback on complex display setups. In UE 5.8, to provide a more balanced playback experience to our users, we are adding TMV, a video container for tiles and mips with compression. This will address the extreme file size overhead of EXRs and bandwidth requirements for high performance video playback.

This targets ICVFX, Live Events and anyone requiring a solid video format for game engines.

TMV helps users to achieve the following:

• Best-in-class video playback in-engine (streams from disk only required pixels instead of decoding whole video frames)

• Smooth scrubbing (on-par with Apple Pro Res scrubbing performance)

• High image quality while keeping storage footprint reasonable (lossless & lossy compression algorithms)

• Support for high-bit depth HDR encoding

• Low latency support for displaying only what is necessary in the field of view. Tiles can be streamed in and out based on the tile requested.

Video Transcoder (Experimental)

Professional video editing tools often transcode incoming video assets into a common optimized video format for enhanced scrubbing and editing capabilities. In UE 5.8, we are adding an experimental video transcoding tool that can take most industry available input formats into our new TMV (Tiled Mipmap Video) video container.

Once transcoded, the video asset becomes available for playback in the engine like any other format. The main difference is that TMV is optimized for playback in the context of game engines and 3D rendering.

This is targeting users from any industry requiring transcoding video to EXR or TMV container (with or without tiles & mips).

Specifically in this release we are adding the following:

• Job management (add, duplicate or remove jobs)

• It can execute jobs as commandlet (CLI)

• Export tool configuration to json format

• Live transcoding progress preview

• Support for both image sequences (including EXR) and video files

• Tiles and mips customization

• Color management and overrides

• Quality settings

Media Viewer (Beta)

Often animators need to align their animations against existing reference footage. In 5.6 we added the capability to dock media (images, media textures, video files, live viewports) next to where animation work is done.

Two AB banks in either horizontal or vertical configurations help compare two sets of assets. Zoom and pan controls can be used to further align content. Bookmarks quickly recall asset configuration with hotkeys. In UE 5.8, the Media Viewer plugin gets closer to Production Ready as it includes the following workflow and usability improvements:

• Enhanced workflow for accessing Sequencer media textures.

• Horizontal/vertical image bank flip.

• Zoom level adjustable filtering mode with pixel grid display.

• TMV (Tiled Mipmap Video) support.

For more information on this feature, see Media Viewer. 

Simulation and VFX

Chaos Destruction

The Chaos Destruction system provides a powerful set of tools for achieving cinematic-quality destruction in real time, combining high visual fidelity with strong performance optimization. UE 5.8 updates include:

Editor

• A default Dataflow template is now available when creating an asset.

• New assets now show an icon on their thumbnails indicating they have a dataflow attached.

• We added render settings for geometry collection renderable types.

Component

• Added the possibility to set the linear and angular damping per transform.

• Added new Blueprint functions to query current transforms:

  • GetCurrentTransforms

  • GetCurrentTransformsFromIndices

• Fixed incorrect indexing in the Niagara Destruction Data interface, which was causing some particles to spawn at the origin.

• Fixed setting collision response on a geometry collection component.

• Added support for GyroscopicTorque option to geometry collections.

• Fixed velocities not being properly set on the GT particles when syncing from the game thread.

• Updated the character movement to properly pass the bone name to the function that gets the linear velocity.

• Fixed traces not always working on partial clusters when using remove on break/sleep.

Fields

• Fixed a potential crash when a field processes a partial cluster.

For more information on using this feature, see Chaos Destruction.

Chaos Dataflow Editor

Dataflow is Unreal Engine’s node-based system for procedural generation of physics-based assets. It’s widely used in workflows for Cloth, Destruction, Hair, Flesh, and MetaHuman setups. UE 5.8 updates include:

• Runtime graph evaluation.

• Enhanced UI and UX (more interactive tooling, gizmos, and more).

• Skeletal mesh authoring.

  • Improved geometry tools (merging).

  • A more complete toolkit for creating constraints.

• In-graph caching.

Chaos Visual Debugger

The Chaos Visual Debugger (CVD) provides Unreal Engine users with a way to effectively observe and debug their physics simulations, either directly in the Unreal Editor or from a standalone CVD instance. UE 5.8 updates include:

• A camera tracking system.

• The geometry visualization panel.

• Multi-select support.

• A trimesh complexity view.

Chaos Core

We are adding foundational improvements to Unreal Engine’s Chaos physics system to support more responsive and scalable simulation workflows. UE 5.8 updates include:

• Improved thread-safe island generation.

• More control over object sensitivity and island sleeping.

• Better intra-island parallelisation via spatial or color separation.

• A protected solver API and new execution model.

• Continued work to remove the monolithic physics thread and move to the job graph.

• An extended metaverse-ready filtering model:

  • 64-bit channels.

  • Channel masks vs. single channel selection.

  • Extended filters beyond 64 channels.

• Skeletal mesh authoring in Dataflow

• Better scale and clamping within the rigid body and deformable solvers.

  • Local space simulations.

  • Velocity clamping.

  • Remove ImplicitObjectScaled for per-shape scale.

• Chaos++ solver node for Dataflow use, to prove out early API external to the world solver.

Chaos Caching

The Caching framework project focuses on extending the existing system for storing and replaying simulation data efficiently across Chaos-based features like Cloth, Fluids, Destruction, and Flesh. UE 5.8 updates include:

• Per-component caching in sequencer.

  • Supports both editor-side baking and runtime playback.

• Using the Chaos cache asset as a meta-asset pointing to more relevant optimized formats.

• Added tools for cache versioning, trimming, and invalidation.

• Cinematic workflow validation.

  • Cloth rest posing in sequencer.

Chaos Hair

For Chaos hair, UE 5.8 updates include:

• Expanded support for painting attributes, skin weighting, and guide swapping.

• Nanite compatible rendering and simulation.

• Card generation to skeletal mesh.

• Groom editing tools (cut / curl).

• Prototype strand rendering.

Chaos Flesh

This project focuses on unifying the Chaos solvers for cloth and flesh into a single deformable simulation framework. The UE 5.8 updates include:

• Merged cloth and flesh solvers into one deformable core.

• Enabled procedural interactions between layers (skin, muscle, garment).

• Improved performance through shared memory and solver logic.

• Updated Dataflow nodes to use the new Dataflow rendering system.

Chaos Cloth

With UE 5.8, Chaos cloth is production ready. Updates include:

• Enabled non-destructive updates and round-trip editing with CLO/Marvelous Designer.

  • Import USD constraints and cloth attributes into Unreal Engine.

  • Preserve panel structure, springs, and simulation metadata.

• Supports simulation playback and re-authoring in Dataflow.

• Enabled procedural interactions between layers (skin, muscle, garment).

• Improved performance through shared memory and solver logic.

• Cloth Interactor asset data to help manage setting groups of properties from Blueprints.

• Added fictitious forces on full velocity scale simulations.

Chaos Modular Vehicles

The Modular Vehicle system gives users the ability to build vehicles in real time using dynamic scene graph components rather than relying on fixed skeletal meshes. Designed with client-predicted and server-authoritative physics, it supports flexible construction. This system empowers creators to craft traditional or unconventional vehicles using modular parts within Unreal Engine.

• Added support for constructing vehicles using a skeletal mesh, giving users a way to easily create simple vehicles with the same framework.

• Added two-way interaction between the vehicle and the ground.

For more information on this feature, see Chaos Modular Vehicles.

Platform SDK Upgrades

• Windows

  • Visual Studio 2022 v17.14 or newer

  • Windows SDK 10.0.22621.0 or newer

  • LLVM Clang

    • Minimum: 18.1.8

    • Preferred: 20.1.8

  • Intel OneAPI

    • Minimum: 2025.2.0

    • Preferred: 2025.2.0

  • .NET 8.0

• IDE Version the Build farm compiles against

  • Visual Studio 2022 17.14 14.44.35207 toolchain and Windows 10 SDK (10.0.22621.0)

  • Xcode 15.4

• GDK

  • Minimum Windows SDK: 10.0.22000.0

  • GDK: April 2025

  • 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 20.1.8

  • Cross-Compile Toolchain: v26 clang-20.1.8-based

  • Note: Unreal Engine on Linux users must update their OS to use SDL3. For more information, see Updating Unreal Engine on Linux to SDL3

• macOS

  • Recommended OS: Latest macOS Sonoma 14

  • Minimum OS: macOS Sonoma 14.0

  • Recommended Xcode: 15.4 or newer

  • Minimum Xcode: 15.2

  • Supported macOS SDK: 14 and newer

  • Note: Supported Xcode versions were downgraded from UE 5.6  due to some issues with compiling and linking when using the latest versions.

• iOS / tvOS / iPadOS / visionOS

  • Recommended OS: Latest macOS 14 Sonoma

  • Minimum OS: macOS Sonoma 14.5

  • Recommended Xcode: 16.1 or newer

  • Minimum Xcode: 15.4

  • Supported Target SDK versions:

  • iOS SDK version: 15 or later

  • iPadOS SDK version: 15 or later

  • tvOS SDK version: 15 or later

  • visionOS 2.4 with Xcode 16.3 recommended

    • Note: v2.5 and x16.4 passed a very limited test and are likely good. Versions down to v2 and x16 are likely to work.

  • 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 r27c

  • 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. This is fixed with 35.0.1.

  • 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 does 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+.

• EOS

  • 1.18.1.2-47370208

• Steam

  • 1.57

• Switch

  • Default SDK Version: 20.5.6

  • Default Firmware Version: 20.1.0-2.2

  • Minimum SDK Version: 18.3.1

  • Minimum Firmware Version: 18.1.0-1.0

  • Nintendo Package Manager: 1.7.0

  • Supported IDE: Visual Studio 2022

• Switch 2

  • Default SDK Version: 20.5.6

  • Default Firmware Version: 20.1.0-2.2

  • Minimum SDK Version: 19.3.5

  • Minimum Firmware Version: 19.1.0-1.4

  • Nintendo Package Manager: 1.7.0

  • Supported IDE: Visual Studio 2022

• PS4

  • Default Orbis SDK 12.508.001

  • Minimum Orbis SDK 12.008.011

  • System software 12.508.001

  • Supported IDE: Visual Studio 2022

• PS5

  • Default Prospero SDK 11.00.00.40

  • Minimum Prospero SDK 10.00.00.48

  • System Software 11.00.00.43

  • Supported IDE: Visual Studio 2022

• ARCore

  • 1.48

• ARKit

  • 4.0

• OpenXR

  • 1.1.46

  • OpenXR 1.0 and 1.1 runtimes are supported, either can be disabled in project settings.

Release Notes

AI/ML

New:

• Learning Agents: Remove firing OnAgentsAdded and OnAgentsRemoved if they are empty.

• LACombat: Split schemas into a separate map and make recordings filterable with tags.

Bug Fix:

• Learning Agents: Fix memory leak in LearningAgentsRecorder.

MCP

New:

• Added an assistant toolset for animation features.

Bug Fix:

• Fixed boolean type parsing issue with ECA Bridge.

Neural Network Engine (NNE)

New:

• Upgraded ONNX Runtime to 1.24.3 and DirectML to 1.15.4 in the NNERuntimeORT plugin.

• Upgraded the NNERuntimeIREE third-party compiler, runtime, and tools to IREE 3.11.0.

• Added per-model compiler flag settings for the NNERuntimeIREECpu runtime.

• Added.mlpackage import support to the NNERuntimeCoreML runtime.

• IREE runtime trace zones from NNERuntimeIREE are now captured by Unreal Insights in non-Shipping configurations.

Deprecated:

• Removed: Dropped the NPU execution interface from the NNERuntimeORTDml runtime.

Animation

New:

• Added accessors for Vector and Quaternion attribute types to SkeletalMeshComponent.

• Marked UAnimNotify as EditInlineNew.

• Added virtual Merge function to UAssetUserData.

• Made the Animation Curve Debugger Widget read-only per default.

• Added a remap (v, min_in, max_in, min_out, max_out) function to the Curve Expression plugin. This function remaps the input value such that its value within the in_min/max range is linearly mapped to the out_min/out_max range, much like the FMath::GetMappedRangeValueClamped C++ function.

Bug Fix:

• Fix infinite loop in rich curve feature point search function.

• Remove improper usage of FKeyHandle constructor Reduces unique key ID churn.

• Fix for PoseableMeshComponent for when Skeleton changes during its lifetime.

• Makes AnimationEditorPreviewScene and the EditableSkeleton (more) robust to the Skeleton being deleted.

• Fixed restoring of animation position and play state in montage and animation editors after undo/redo actions.

Deprecated:

• Cleaned deprecated methods from Animation.

Animating in Engine

New:

• Curve Editor

  • The Curve Editor's frame hotkey now zooms to your selected keys' range, or falls back to the selection/playback range when nothing is selected, matching Sequencer's framing behavior.

  • Copy/pasting curves now applies the source curve to every selected target with a matching name, not just the first match.

  • The tree view now has an Organize and Sort menu which has options to Expand/Collapse Nodes, Expand/Collapse Nodes and Descendants, Expand All Nodes, Collapse All Nodes, and Sort All Nodes.

  • Added Middle Mouse Button Adds Key setting to enable or disable adding a key with the middle mouse button.

  • Ctrl-mouse wheel and alt-right mouse button now zoom horizontally even when there's no curves selected.

  • The selection range start/end shortcut binding now shares Sequencer's binding so the behavior stays consistent across both.

  • Toolbar cleanup by removing the unused All Edits button and the 'Curves' label from the pulldown.

• Anim Details

  • Anim Details now shows an option to remove all keys in the right-click context menu of its properties.

  • Anim Details now groups Control Rig properties with identical names, regardless of their relation in the rig.

    • Control Rig Controls are now grouped per property name, ignoring their parent, while common Actor properties still show grouped per parent Actor Components as previously.

    • Groups now show the control name if multiple parents with identical name are multi-edited and "Multiple" only if controls of different short names are multi-edited.

    • Groups now show a tooltip listing up to 5 controls when multi edited.

• Added Blueprint functions Open Pose Library Tab and Close Pose Library Tab.

• Snapper settings are now saved as user preferences.

Bug Fix:

• Curve Editor

  • Normalized and Stacked views no longer collapse all keys to the bottom when the curve values are nearly identical.

  • Improved interaction by not changing curve selection if there's nothing to change and not transacting key drags if there's no movement.

  • The Normalized view now respects the Frame Output Padding setting instead of using a hardcoded 10% margin.

• The time offset filter now handles pre and post infinity extrapolation by wrapping around.

• Tween slider now responds to both its primary and secondary keyboard shortcuts.

• The Tween Slider no longer fails to show up if the mouse is too close to the left border of the viewport.

• The pose browser now maintains its configuration and doesn't rebuild each time a pose is selected.

• Anim Layers UI now follows add/remove/duplicate layers and undo/redo, regardless of whether controls are selected or not.

• Enums now show their keyed status in Anim Details.

• Changes to bool, float and int properties in Anim Details are now reflected in Sequencer.

• Selecting plain Location Controls in Anim Details now filters channel curves correctly.

• Control Rig and Sequencer: Fixed Control rigs recreated with "Recreate Control Rig with New Settings" reverting to default setting when entering PIE.

Character Customization

New:

• Added support for Chaos ClothAssetSKMClothingAsset.

• Renamed Passthrough nomenclature to Object. This new naming convention gives insights to the user when a UObject is created.

• Merged Texture and Passthrough Texture nodes.

• Added new Skeletal Mesh type and nodes. This new type allows users to work at Skeletal Mesh level without having to enumerate all Mesh Sections.

• Converted Add To Component SKM node to Modifier Skeletal Mesh Merge.

• Added Skeletal Mesh output pin to Skeletal Mesh Parameter node.

• Added the "Skeletal Mesh Modify" node.

• Removed one Game Thread tick when Updating. Updates now can take a minimum of two ticks.

• Added Asset User Data type and nodes.

• Added new UAssetUserData type and nodes.

• Added the "Mesh Transform with Bone" node to serve as an inlined version of the modifier node with the same name.

• Added the "Remove Mesh" node.

• Implemented Parallel Updates. Now MIPs and LODs and Initial Updates can be generated in parallel.

• Added support for Clothing in Skeletal Mesh parameters.

• Components now can have the same name.

• Added the option to taking the ownership of generated resources. Mutable will not modify or reuse them.

• Added Material Override pin to components.

• Added the "Skeletal Mesh Break" node.

• Added Passthrough Skeletal Mesh pin to Node Passthrough Skeletal Mesh Component.

• Added Passthrough Texture Parameter node.

• Added custom External Operations. Allows users to create new operations. Very experimental!

• Moved Modifier Skeletal Mesh Mesh LOD Pins to a Skeletal Mesh Make.

• Marked Transform in Mesh nodes as deprecated.

• Added an option to define the maximum UV layout size, in blocks, for the Mesh Section and Material Modify nodes. The size of runtime-generated textures is derived from the 'Max Layout Blocks' setting and the in-game size of the reference textures.

• Hidden compile properties when a CO is a Child.

• Removed Parameter Profiles.

• Removed Node Copy Mesh Section.

• Added support for SkinWeightProfiles in Skeletal Mesh Parameters.

• Removed CO States tab.

• Hidden Child Object properties when it is not the root.

• Removed selector list from Mesh Morph. Now it is a simple string.

• Optimized Skeletal Mesh merge operations.

• Added Skeletal Mesh Break node.

• Added NodeSwitch for Skeletal Mesh Objects.

• Added Skeletal Mesh Merge node.

• Added the "Skeletal Mesh Morph" node.

• Improved usability of the debugger by adding the option to color the tree of operations using the operation data type.

• Add Serialization Support for Material Params in LoadDescriptor.

• Optimized mutable runtime performance by transforming chains of conditional ASTOps into switches.

• Changed Group Type option names.

• Allowed Reroute Node to have multiple outputs.

• Refactored the Mutable system tick to reduce the time spent on game-thread.

• Improved mutable runtime performance by the removal of the "Task_Game_LockCache" task from the Customizable Object Instance update.

• Optimized Game Thread BuildOrCopyClothingData.

• Image layer operation optimizations.

• Added support for Skeletal Meshes with unlimited bone influences in Skeletal Mesh Parameters.

• Added support for Skeletal Mesh sockets in Skeletal Mesh Parameters.

• Improved the reporting of cyclical CO references.

• Moved all functionality of the Passthrough Mesh Component" node into the "Skeletal Mesh Component" node. Removed "Passthrough Mesh Component" node.

• Allow use of Skeletal Meshes without NeedsCPUAccess enabled in Skeletal Mesh Parameters.

• Real-time morph generation optimizations.

• Added support for PhysicsAssets in Skeletal Mesh Parameters.

• Remove LOD limiters CVars.

• Moved loading CO hierarchies from synchronous to asynchronous.

• Make FCustomizableObjectInstanceDescriptor Load/Save functions safer.

• Removed Share Projector Between LODs optimization.

• Added backward compatibility support to Customizable Object Macro libraries to update nodes within macros.

• Changed Break Skeletal Mesh node color.

• Removed Low Priority Textures.

• Removed Material references from Generated Textures in Texture Analyzer.

• Added colors to Performance Analyzer.

• Added 'Bone Pose Priority' property to object group nodes to resolve conflicts when merging meshes with different poses.

• Added the option to define the output prefix for the assets generated by the mutable Customizable Object Instance Baking operation.

Bug Fix:

• Fixed "Clip mesh with UV Mask" operation not loading the appropriate texture mask mip.

• Fixed an issue with MinQualityLODLevels where the streamer would request Skeletal Mesh LODs below the platform MinLOD setting.

• Fixed actor creating more components than it should.

• Fixed high video memory usage when generating a lot of meshes in the CustomizableObject editor.

• Fixed modifier nodes not being able to display the UVs of mesh section nodes that did not define at least one non-automatic tag.

• Hair Strands Mutable: Fixed check failure when trying to create a new UObject from the PostLoad of the "Groom Constant" node.

• Fixed OOM crash when moving a slider.

• Fixed modifier nodes missing the input "RequiredTags" input pin on node refresh.

• Fixed unable to save baked resources if they contain invalid characters.

• Fixed multiple cases where the messages produced by mutable did not get exposed in the "Stats" Customizable Object editor tab.

• Fixed "unable to remap pin" warning during the update of the "CONodeMeshMorphStackDefinition" backwards compatibility code execution.

• Fixed compilations not using the root CO compile options.

• Fixed multiple issues with Reshape nodes.

• Fixed wrong order of the Customizable Object versions array making a backwards compatibility related fix for a missing pin be performed after it was required.

• Fixed modifiers always applying when All Required + No Tags.

• Fixed bake operation not re-compiling the Customizable Object when the compiled data is outdated.

• Fixed an issue where Skeletal Mesh Component nodes added to child Customizable Objects were ignored.

• Fixed crash when the RunCode operation was aborted when the material parameter could not be found.

• Fix for automatic compilation in editor not picking up on changes from in a Customizable Object Macro Library. Now changes will be picked up on autocompilation and be represented in the output.

• Fixed PrepareUnrealCompression Game Thread check.

• Fixed ImagePixelFormat not being used in Bake.

• Fixed crash when validating Customizable Objects.

• Fixed Code Viewer stack overflow crash with large COs.

• Fixed a memory leak when converting Skeletal Meshes from Skeletal Mesh Parameters at runtime.

• Fixed ensure when registering to Movie Sequence Template actors using HairStrandsMutable.

• Fixed Customizable Object being GC during package splitter.

• Fixed an issue with Skeletal Mesh streaming where streamed LODs remained in memory until the Skeletal Mesh was destroyed.

• Fixed Material Switches losing its type.

• Fixed Extension Data not being applied when an Instance is already generated.

• Fixed crash if the PinType is None.

• Fixed modifier nodes not showing the custom tags explorer UI element.

• Fixed morph-related error messages not having the node context set in them.

• Fixed UVs changing precision when streaming.

• Fixed crash when failing to stream an Image.

• Fixed scaling issue with the Layout areas caused by the unrequired clamping of the layout areas when not really needed.

• Fixed crash when removing all vertices of a cloth section.

• Fixed cloth crash when streaming was enabled + using a Remove Mesh node.

• Fixed the "FCustomizableObjectMeshStreamIn" tasks leaks that caused the "FLiveInstance" and "FCustomizableObjectMeshStreamIn" objects to be wrongfully kept in memory.

• Fixed Callback check when Streaming in FCustomizableObjectMeshStreamIn.

• Fixed PSO check with grooms.

• Fixed crash when deserializing meshes with cloth.

• Fixed CO always automatically compiling.

• Fixed CO loading hang when a Child Object was not properly connected to a group.

• Fixed loading incorrect CO hierarchies.

• Fix Mutable compilation crash.

• Fixed crash during the generation of a Mutable Mesh from a Static Mesh.

• Fix crash when converting constants that had as a child an IM_REFERENCE.

• Made the "Material Modify" editor node ignore the non-input pins during the node compilation.

• Fixed case where an error during the COI update made it still eligible for being updated each time the ticker got ticked.

• Fixed crash when opening an empty CO.

• Fixed crash in ConvertSkeletalMeshToMutable when the SkeletalMesh is missing.

• Fixed late initialization of the NeedsCPUAccess flag for FSkinWeightVertexBuffer.

• Fixed crash when opening the Code / Graph Viewer without model.

• Fixed parameter discoverability issue when multiple UVs require layout generation.

• Fixed crash with Mesh and Image parameters being nullptr.

• Fixed reported Task times in Performance Analyzer.

• Fixed Dataless crash when streaming inline SKM LODs.

• Fixed modifiers not being applied correctly with optimization None.

• Fixed GetModelResources crash when cooking.

Deprecated:

• Deprecated ComponentIndex in favor of ComponentName in CustomizableSkeletalComponents. Moved the remaining CustomizableSkeletalComponent properties to private.

• Removed the option to generate 'Only manually created LODs' in favor of automatic LODs.

Control Rig

New:

• Control Rig Physics

  • Implements the per-body PhysicsBlendWeight.

  • Setting the StepPhysicsSolver alpha value to 0, disables simulation, switches the node to a cheap pass-through mode, and prepares the simulation to restart if alpha is subsequently set > 0.

  • Add support for acceleration vs force mode (a simple toggle) in controls.

  • Add an option to scale damping by inverse mass. This is to allow users to choose whether damping acts to simply calm down the simulation, vs behaving more like drag (air resistance)

  • Support resetting the simulation if the absolute time between updates is above a threshold.

  • Improves the way that settings for the solver and simulation space motion etc are exposed.

  • Adds "GetPhysicsBodyExists" and similar Get calls for the other types of component.

  • Add cvars for debug visualization control.

  • Control Rig Physics now supports convex shapes. Note that this is especially useful when importing from a physics asset using convex shapes.

  • Control rig physics supports continuous collision detection (CCD) as an option on the solver and individual bodies.

  • Control Rig Physics plugin is now enabled by default.

  • Control Rig Physics optimisations/speedups.

  • Improve tooltips/help.

  • Rename BonesToUse to BoneMask in relevant nodes.

  • Improve instantiation from a physics assert, to let modular rigs work better. Now physics on the whole character can be instantiated limb by limb, and the junctions will not be missing joints/controls.

  • More get/set functions exposed to the control rig graph.

• RigVM

  • Added new math node "Get Rotation from X Vector"

  • Added "Sphere Trace By Profile" and "FRigUnit_LineTraceByProfile"

  • Control Rig/RigVM: Add support for text rendering with DrawText().

  • Allow structs within RigVM to implement ImportText for cache management purposes.

  • Improve usability of the RigVM Print node - defaults to display for a single frame, and the duration is more clearly exposed.

  • Clarify RigVM help text for some trig functions.

    • Adds a maths "Wrap" function to RigVM.

  • Removed RigVM cached handles array from instances, as a memory saving optimization This also eliminates the need to patch handles for each instance initialization (it generates patched handles on the fly for each instruction).

  • RigVM now preprocess handles using offsets at CDO creation Added cvars to allo tweak / disable RigVM parallel_for on some platforms.

• Add an option to directly edit redirector nodes.

  • New option in Editor Settings → Rig VM Editor → Direct Reroute Node Editing, disabled by default.

  • When enabled, reroute nodes are dragged by default, and create connections with Ctrl-Drag.

  • When enabled, when double clicking near a line, a reroute node is created and connected to the nearby line.

• Control Rig Dynamics: This is a new experimental plugin that adds support for fast physically-based dynamics in Control Rig. This allows simple cosmetic dynamics to run significantly faster than the equivalent Control Rig Physics setup, making it better suited to gameplay scenarios.

• Rework space editing, add multi-editing support.

  • When selecting multiple controls in a viewport, spaces can now be edited for all selected controls.

  • The add spaces menu now only shows valid spaces.

  • The bake spaces dialog now shows custom spaces.

  • Adding the default parent no longer adds a duplicate parent entry, the default parent is briefly highlighted instead.

• Add an option to show only empty sockets in the schematic viewport, defaults to true.

• Add cut, copy, paste and delete commands to the graph node's right click context menu.

• Control rig physics and dynamics: Add debug UI for physics and dynamics, activated by buttons on the Control Rig editor toolbar. Also added to the Tools→Debug menu, as this can be used during PIE too.

• Make baking to control rig procedurally equivalent to the UI codepath in terms of how we deal with pre-existing control rig tracks.

• Allow physics control rig users to differentiate collision against world bodies by collision type (i.e. physics, query, probe). Also refactor ISM specific code to simplify implementation.

• Improve settings.

  • Separate menu settings between level editor and asset editor.

  • Settings for the level editor are now stored where applicable.

• Curves referenced in the graph are now highlighted in the Curve Container tab.

• In a Control Rig Graph dragging from a node and pressing F now spawns a for each node.

• Fix for CRP to correctly add world bodies that are owned by instanced static mesh components.

• Add a new option "Compile Resets Solve Mode" in the Event Queue menu, default to true.

• New hotkeys Editor Viewport:

  • Bones: Alt-B

  • Controls as Overlay: U

  • Nulls: G

  • Sockets: H

  • Axes on Selection: J

  • Graph:

  • Profiling: P

  • Next Event Queue: M

  • Prior Event Queue: Shift-M

  • Toggle Forwards and Construction: Ctrl-M

  • Rig Hierarchy:

  • New Socket: Ctrl-K

  • Module Hierarchy:

  • Show Secondary Connectors: Ctrl-Shift-1

  • Show Optional Connectors: Ctrl-Shift-2

  • Show Unresolved Connectors: Ctrl-Shift-3

  • Duplicate: Ctrl-D.

• Add an option to duplicate Modules from the Module Hierarchy context menu.

• Rig modules now can add an Array Size Rule for Connectors to express the expected number of connections.

• Searching the Module Hierarchy in Modular Rigs now also finds entries by the Control Rig Module class when said column is visible.

• Anim Outliner, Anim Details, Sequencer and Curve Editor now show Controls in the same order.

• Set Default Match is now a template node that accepts both single connectors and an array of connectors.

• The Modular Rig Hierarchy Tree View now supports recursively expanding/collapsing elements by Ctrl-clicking nodes.

• Creating a Control Rig asset in the content browser now allows picking Rig Module in addition to Control Rig and Modular Rig.

• Connectors in Modular Rigs can now also be dragged from the details panel.

• Improved columns in the Modular Rig Hierarchy.

  • Columns can now be shown or hidden when right clicking the header.

  • Added new columns Module Class and Module Tag, both hidden by default.

• Modular Rigs now show the Schematic Viewport when dragging modules.

• The Modular Rig Editor now shows the class name and a browse to asset icon along with the class path in Details.

• Mirror settings are now stored per project per user.

• The Modular Rig Hierarchy editor now stores the connector visibility filters per project per user.

• Views where Connectors could not be reordered now show a small icon to declutter the view.

• Modules in Modular Rigs now show a combo box to select Control Shapes, including Shapes from the Shape Libraries of the Module's Control Rig, Shape Libraries of the Modular Rig and Direct Mesh Control Poly Groups.

• Connectors in Rig Modules now have a description property which the Modular Rig Hierarchy displays as a tooltip.

Bug Fix:

• Control Rig Physics

  • Clamp strength so that values < 0 don't cause unwanted behaviour.

  • Fix parent-space controls not finding the parent body when instantiating from a physics asset.

  • Fix serialization of shapes (name and ContributeToMass).

  • Ensures that world objects get initialised in the collision system properly: Fixes problems with objects not colliding unless they have moved.

  • Improves/fixes some automatic collision shape generation.

  • Collision fixes for when bodies have no shapes.

• RigVM

  • Fix for inline edit conditions not getting updated when toggled.

  • Missing comma in python print for add_reroute_node_on_pin.

  • RigVMEdGraph call PostEditChange after calling modify in RemoveNode.

  • Update RigVM function reference nodes when adding or removing variable references to the contained graph.

  • Avoid RigVM crash when there is a function with a missing pin in the injection data.

  • Disabled RigVM function parameter customization on aggregate nodes.

  • Fixed RigVM NotEqual operand.

  • Fixed RigVM debug info use after delete leading to crashes.

  • Fixed RigVM equal dispatch node type check to allow comparing compatible types, like enums with uint8 encoded enums.

• UAF

  • Fix for not being able to clear uobject references on rig vm properties via the details panel.

  • Crash fix for mixed usage of 16bit and 32bit pose indices in AnimNextControlRigPoseAdapter.

    • Fix incorrect accessor ControlRigPoseAdapter::GetGlobalPose() actually returning the local pose.

• Control rig dynamics and physics: Clear arrays during initialisation. This has no effect in normal use, but when using the COntrol Rig Construction Event mode, it prevents these arrays from unbounded growth.

• Fixed for some Control Rigs not correctly centered on asset editor start.

• Move to using a struct for world object keys to avoid potential collisions within TMap when previously using hashes as keys.

• U Rig Hierarchy::CanCauseCycle no longer ignores inactive parents, no longer ignores inactive parents, which previously could cause cyclic dependencies.

• Ensure that all run once events are cleared at the end of Execute. This prevents any custom run once events from being run every frame.

• Fix a crash in ControlRigParameterTrackEditor when Controls are selected outside of the game-thread, for example during undo/redo.

• Fixed Control Rig copy hierarchy reallocate elements breaking the target elements subindex.

• Fix for an issue where get user data was failing to find uobject types in the RigVM asset registry due to incorrect formatting on the type strings.

• Control Rig crash fix for use after delete at control shape creation.

• Fix issues with rendering bones and local rotation axes in level editor and asset editor.

• Frame Selection (F) now works in the Control Rig Editor.

• Modular Rig modules can now be rearranged within their parent after undo/redo.

• Control rig assets are dirty upon re-opening.

• Fixed Control Rig AST generation, to avoid function entry variables being included in scope blocks.

• Adding the first bone to a Control Rig and undo/redo now restores the bone.

• Fixed Control Rig function parameter type selection not allowing array types.

• The Modular Rig Hierarchy now allows reordering Modules within the same parent as expected.

• Connector Rules are now respected when selecting elements in Modular Rig Details.

• Fix an issue in the Modular Rig Editor where the reorder handle for Array Connectors was not visible.

• Fix various issues in Module Hierarchy's functionality.

  • Mirror modules now mirrors children and retains the mirrored sub-hierarchy.

  • Fix details are not refreshed when a connection array is cleared in the module hierarchy.

  • Fix clearing connector arrays with related button did not clear the array.

  • Fix the details view did not update when the connector array was cleared.

  • Fix the last connector in a connector array could not be removed.

• Fix for the GetChainLength function to return the total chain length instead of the average.

• Control Rig Modules Connector Details no longer show the connectors as array when the Is Array property is set to false.

• The Rig Hierarchy and the Module Hierarchy now keep their selection and expansion after compiling.

• Fix issues where the Module Hierarchy did not always allow scrolling. Issues where Connectors are displayed in the Module Hierarchy remain in certain cases.

• Fixed debug draw smearing on Control Rig.

• Fix an issue where Control Shapes remained partially selected in Modular Rigs when a Rig Module was compiled.

• Fix Control Rig import from text heap use after free, due to the relocation of the element transforms after adding a new element.

• Fixed Modular Rigs overrides causing an infinite recursion in the tagged property serialization.

• Fixed a Control Rig crash adding a graph after renaming another newly added graph.

Deprecated:

• Deprecate FRigControlElement::Settings direct Blueprint access -- adds deprecated UPROPERTY so existing BP graphs still work with warnings, and adds GetControlSettings(Key) BlueprintCallable as the migration target.

• Cleaned deprecated methods from UAF (up to 5.6).

• Cleaned deprecated methods from RigVM (up to 5.6).

• Cleaned deprecated methods from Motion Warping (up to 5.6).

Deformer Graph

Bug Fix:

• Deformer Graph

  • Fixed crash when using secondary skeletal mesh component binding in a deformer graph.

  • Fixed various crashes and assertions in Deformer Graph when it is used in a Control Rig while Asset Save is ongoing.

• Fix issue where deformer settings were lost during bp component reinstancing process.

Gameplay

New:

• Pose Search

  • PoseSearchDatabase editor multi selection improvements.

  • Pose Search databases created for Chooser Columns now default to BruteForce, since KD Tree usually fails with external filtering.

  • PoseSearchColumn support for unique PoseSearchDatabase per row.

  • PoseSearchColumn (motion matching integration with choosers) bug fixes.

  • PoseSearch plugin motion matching drawing bug fixes.

  • Added a project setting (Project Settings → Pose Search → MaxDatabaseEditorPreviewActors, default 50) that caps the number of actors spawned in PoseSearchDatabase editor.

  • U Pose Search Interaction Asset::CalculateWarpTransforms improvements.

  • Added Experimental BlueprintCallable UPoseSearchInteractionLibrary::MotionMatchMulti, new API to perform multi character motion matching searches without any frame delay.

  • New PoseSearch plugin Blueprint callable OverridePoseHistoryFromOwningMesh function to override the pose history pose with the mesh pose to enable, for example, motion matching physics poses.

  • Added UAnimNotifyState_PoseSearchSamplingRange notify state, used to to include animation segments into PoseSearchDatabases.

  • Strip out disabled PoseSearchDatabase animations during cook.

  • Fix montage trajectories not working when operating on pawns not characters.

    • Make montage prediction CVar `a.PoseSearchTrajectory.UseWarpedMontage` affect Mover / when using predictor as well.

  • Add support for experimental posesearch generation of warped montage trajectories.

    • Remove all direct actor transform references from root motion modifiers.

    • Add 'UMotionWarpingTrajectoryAdapter' which may optionally exist on a 'UMotionWarpingComponent' to predict trajectory.

    • Add `FRootMotionModifierSwapState` to store warping state pre-prediction and restore state post prediction.

    • Add "Prediction Mode" to 'UMotionWarpingComponent' where it uses the swap state / new adapter to predict warped trajectories.

    • Add Experimental `UPoseSearchTrajectoryLibrary::PoseSearchGenerateWarpedTransformTrajectory` to generate warped trajectories.

    • Add `GVarPoseSearchTrajectoryUseWarpedMontage` to enable warped montage trajectories by default.

  • Improved UPoseSearchInteractionAsset warping calculations.

  • Removed some UE 5.6 deprecations from PoseSearch plugin.

  • Optimized PoseSearchDatabase DDC key generation by removing template objects.

  • Renamed few motion matching stats from the PoseSearch stat group (Search Brute Force, Search PCA/KNN, Search VPTree, Search Event into PoseSearch Brute Force, PoseSearch PCA/KNN, PoseSearch VPTree, PoseSearch Event).

• Account for mesh scale when calculating Motion Warping warp points. Enable with a.MotionWarping.UseMeshScale.

• Exposed UMotionWarpingComponent::FindWarpTarget as BlueprintCallable.

• Add handling for angular velocity to trajectory history tracking so that spinning platforms are handled properly.

• Add Anim Node Functions to support applying a delta to the offset root bone's internal simulated transform.

• Added UCurveFromSyncMarkersModifier to generate a curve from synch markers.

• Added Blueprint-exposed ResetSync function to reset sync group information on Anim Graph.

• Removed experimental MotionMatchingInteraction node.

• Add a OnInputDeviceHardwareInfoAvailable delegate to the input device mapper, which allows for code to bind to connection events and be guaranteed to run before other systems like Common Input/User code. This makes it possible for the UInputDeviceSubsystem to query the FInputDeviceScope, and make the necessary associations of the known hardware device Id to the new FInputDeviceId.

• Sync group support for follower blendstacks.

• Optimized motion matching interactions performance with a custom hash grid.

• Defaulted motion matching trajectory generation in mesh space rather than using the Character.View.Rotation.Yaw when the character is set to orienting the rotation to movement.

• Added URootMotionModifier_Blueprintable, new MotionWarping URootMotionModifier blue print overridable.

• Motion matching interaction performance improvements.

Bug Fix:

• Pose Search

  • PoseSearchDatabase fix for not being able to copy paste in an empty database.

  • PoseSearchDatabase DDC key generation fix, to support objects with duplicated down dependencies.

  • Fixed a bug where for inconsistent past velocities in motion matching due to history points being offset by delta time, causing noise in past velocity when delta time is not constant.

  • Fixed PoseSearchDatabase editor preview of static mesh attachments.

  • Fixed PoseSearchSchema velocity channel debug visualization.

  • Fix for PoseSearchDatabase indexing looping animation assets.

  • Fixed crash in FAsyncPoseSearchDatabasesManagement::RequestAsyncBuildIndex when database dependent animation assets failed to compress.

  • Fix for missing PoseSearchDatabase indexing on reverting and reloading dependent assets.

  • Fix for UPoseSearchFeatureChannel::CanBeNormalizedWith.

  • Fix for missing FMemMark(s) in FPoseSearchColumn::Filter and FPoseSearchColumn::SetOutputs.

  • Fix for PoseSearchDatabase DDC key determinism when supporting Choosers PoseSearchColumns.

  • Making sure there're no flying animation tasks when on game thread by calling GetProxyOnAnyThread, so it's safe to access animinstance variables in UPoseSearchLibrary::MotionMatch.

  • Fix for UPoseSearchLibrary::MotionMatch crashing when reusing an invalid continuing pose from a previously evaluated schema.

• Motion Warping

  • Add an "AdditionalRotationOffset" in the root motion modifier that allows rotational offset to be specified per animation. This avoids conflicting rotations when warp points are used by multiple different actions. Note that any setup using a rotational offset with facing mode will need to be manually adjusted (this was introduced in 5.7).

  • Deprecated EMotionWarpRotationType::OppositeFacing and EMotionWarpRotationType::OppositeDefault since they can be achieved with an additional rotational offset of 180 degrees (existing data will be automatically converted).

  • Stop using the warp point's rotation offset when in facing mode.

• Fix for crash while changing levels because of invalid FRewindDebuggerTrajectory::WorldToVisualize.

• Fix to allow the DisplayWorldId to be set while analyzing local sessions. Without this, the debugged mesh is lost after the PIE session ends.

• Fix montages do not mark blending out sources as inactive.

• Fix for previewing game generated pose search debugger data with the editor.

• Fix for SearchThrottleTime not working properly in FAnimNode_MotionMatching::UpdateAssetPlayer and FMotionMatchingTrait::PreUpdate.

• Fix for crash in USkeletalMeshComponent::ForEachBodyBelow when instantiated Bodies do not match the SkeletalBodySetups in the Reference Skeleton Mesh.

• Fix for FAssetIndexer::Process crashing on schemas with roles improperly setup.

• Fix issue where GetPoseIndex could return an invalid pose index when there are multiple sampling ranges on the same animation asset.

Deprecated:

• Removed 5.6-deprecated PoseSearch methods.

• Deprecated: UPoseSearchFeatureChannel_Curve::BP_GetCurveValue, UPoseSearchFeatureChannel_Heading::BP_GetWorldRotation, UPoseSearchFeatureChannel_Velocity::BP_GetWorldVelocity, UPoseSearchFeatureChannel_Position::BP_GetWorldPosition, in favor of UPoseSearchFeatureChannel_Curve::BP_GetCurveValueFromContext, UPoseSearchFeatureChannel_Heading::BP_GetWorldRotationFromContext, UPoseSearchFeatureChannel_Velocity::BP_GetWorldVelocityFromContext, UPoseSearchFeatureChannel_Position::BP_GetWorldPositionFromContext, taking the more versatile FChooserEvaluationContext as input.

IK and Retargeting

New:

• IK Retargeter

  • Override Set editor: Add Child, Search Bar, Keyboard Shortcuts, Duplicate, Reordering

    • Added DuplicateRetargetOverrideSet() to the controller API (Blueprint/Python callable). Creates a new override set with a unique name, copying all property overrides, parent assignment, and active-by-default state from the source set.

    • Added "Duplicate" entry to the Override Set tree view context menu between Rename and Unparent.

    • Add Child: Context menu action to create a new override set parented under the selected set.

    • Search Bar: Enabled the built-in details panel search bar for the Override Set editor.

    • Reordering: Added ability to reorder override sets in override set tree.

    • Keyboard Shortcuts: Delete/Backspace deletes selected override set, F2 renames it.

    • Override Set Reordering: Fixed drag-drop to distinguish between reordering (AboveItem/BelowItem) and parenting (OntoItem). Added DisplayOrder field for persistent sort order. Reordering makes the dragged set a sibling of the target at the correct position.

  • Expose bRetainAdditiveFlags to RunBatchRetarget Blueprint/Python API.

    • Added bRetainAdditiveFlags to FIKRetargetBatchOperationInputs so that Blueprint and Python scripts can control whether additive animation attributes are preserved during batch retarget.

• Updated all 17 biped templates to split the existing LeftLeg/RightLeg chains: LeftLeg/RightLeg chains now end at the ankle/foot bone (previously ended at ball/toe) New LeftFoot/RightFoot chains cover the ball/toe bone.

  • IK goals remain on the leg chains, now created at the ankle/foot bone.

  • Updated FBIK auto-setup defaults:

    • SubIterations: 0 → 10

    • Goal ChainDepth: 0 → 2

  • Updated Biped Templates,

  • Added new Templates for Blender Rigify and Meshcapade.

• Add override set dropdown to Batch Retarget window When using a manually supplied IK Retargeter in the Batch/Auto Retarget window, there was no way to select override sets.

  • Added a dropdown (FName with GetOptions) that lists available override sets from the assigned retargeter asset. Selected override set is applied to both the live preview viewport and animation export. Dropdown is disabled when using auto-generated retargeter.

• RigMapper Definition editor graph improvement: Made importing inputs/outputs from Control Rig optional through a check box in import dialogue in order to reduce clatter.

• Improved RigMapper Definition editor graph Comment nodes to fully enclose selected nodes and to trigger on "C" key command.

• Improved validation messages and notifications for RigMapper Definition editor graph. Notifications are now displayed in the graph header. Before they could be seen only in log.

• Added Math Operations feature to RigMapper Definition with a corresponding node in RigMapper Definition editor graph. This op includes all unary, binary and N-array standard mathematical operations selected through the drop down box.

• Improved zooming in/focusing a node and all connected nodes by lowering opacity to non selected nodes and zooming in/out to capture selected ones.

• Implemented Comment node feature for RigMapper Definition graph.

• RigMapper refactoring to include numerous quality of life changes:

  • Improved Undo/Redo system.

  • Persistent node positions between sessions (Graph is no longer recreated every time it is opened).

• Added feature which imports Input curves from Skeletal Mesh.

  • Fixed a problem with RigMapper Definition cache not being cleared when modified.

• Updated IKRetargeter Curve OP stack:

  • RigMapper Op is now a sub-operation of CurveRemap Op.

  • RigMapper divided into RetargetRigMapperUserDataOp which uses RigMapper Definition embedded in target mesh UserData, and RetargetRigMapperOp which contains single RigMapper Definition data asset.

  • Added possibility to select multiple RigMapper Ops in a single substack.

• Implemented RigMapper Definition Graph pin interactions:

  • Added support for breaking links from a node.

  • Added support for moving links from one node to another.

  • Implemented support for adding new connections by dragging and dropping to a different node.

• IK Rig: Allow enabling/disabling anim graph node w/ cvar a.animnode.IKRig.Enable.

• Quality of Life improvements:

  • Allowed adding more pins to nodes and automatically generating connections to other nodes.

  • Fixed a bug with importing a Definition from JSON file.

  • Added constraints when removing pins so the minimal required number of pins are preserved depending on the feature.

  • Improved memory management and performance.

• Reimplemented RigMapper Definition Graph to be interactive:

  • Nodes can be moved around, although position will not pre preserved on reopening.

  • Nodes can be created from a connection or standalone though a context menu.

  • Nodes can be updated through details panel on the right side.

  • Added a Context menu on right click on node or graph.

  • Nodes can be relinked and links can be removed.

Bug Fix:

• Fixed and improved RigMapper Linked Definition validation to include NullOutputs which are subsequently used as inputs.

• Relaxed validation of hanging inputs and outputs for RigMapper Linked and Baked Definitions to allow pass-through with a warning.

• RigMapper definitions tongue fix on RM_CDH_FNM, RM_MHH_CDH and related Linked Definitions and Baked definitions.

• Updated RM_CDH_FNM rig definition to address an issue with inverted corner sharpen and upper eyelid controls.

ML Deformer

Deprecated:

• Cleaned deprecated methods from MLDeformer (up to 5.6).

Physics Control

New:

• Physics Control Component

  • Add BP support for specifying collision ignore/include pairs - Enable/DisableCollisionBetweenBodies.

  • Enable/disable angular drives applies to slerp as well as twist/swing.

  • Make sure that limb-generated controls get automatically added to a set with the limb name.

  • Fixes for Physics Control Component names, so they're never called "". Note that this will change the names of some controls/modifiers, and if those are being referenced explicitly (by name) the assets will need to be patched up.

    • Functions added to log controls/modifiers.

    • Adds checks that controls/modifiers/sets that are passed in are valid (and optionally warns if not).

• Drives now have a Join Limit Violation Response. The available options are: Clamp the skeletal animation drive targets to joint limits, or Widen limits to accommodate the target. In addition to either respecting the joint's limit or the animation, this prevents spurious forces and torques present when drive and limits are fighting (response 'None' option).

• PhysicsControl plugin is now marked as ready for production use.

• Support for applying forces in the control rig physics and RigidBodyWithControl animation graph nodes.

Bug Fix:

• Physics Control Component: Addresses various problems with tick ordering/dependencies so that 1. it waits until the input pose is ready and 2. it ensures the tick is not pushed into PostPhysics by (for example) CharacterMovementComponent when on dynamic floors.

• Guard against the RequiredBones container in RBAN and RBWC InitializeBoneReferences having an empty reference pose (to prevent a crash).

• Fix for bad memory access when world collisions are enabled in RigidBodyWithControl or RBAN.

• Prevent PhysicalAnimationComponent crash if physics blending is enabled mid-tick.

Runtime

New:

• Anim Montage

  • Fixed montage forced position handling during advance if forced position gets updated multiple times without advancing the montage in-between e.g. on sequencer loops or with URO enabled Guarded by CVarUseForcedSequencerMontageLoopBehavior(a.Montage.UseForcedSequencerMontageLoopBehavior). Turned off by default.

  • Added additional safety checks in FAnimMontageInstance::Terminate().

  • Added guarding against negative blend times on montages.

  • Added CVar a.Montage.UseForcedFromPositionAsSubStepOrigin - if ForcedNextFromPosition is set, use it as the sub-stepping origin in FAnimMontageInstance::Advance instead of the previous internal position. Enabled by default.

• UAF

  • Add OffsetRootBone anim node.

  • Add variable container name to variable trace.

  • Translational retargeting trait.

  • Added the option to display trajectory velocity in debug log.

  • Added new OverrideRootMotionTrait.

  • Add InputValue anim node/op.

  • Add FPoseValueBundle as a typed pose overlay for FValueBundle.

  • Implicit cross-skeleton remapping at graph input boundary. Remaps poses automatically when a foreign skeleton enters a graph via PushPose so node authors never deal with cross-skeleton concerns.

  • Add the ability in UAF to specify the end tick group for events.

• RigVM

  • Add package path to some rigvm compile error reports.

  • Add CharacterMovementComponent to allowed class types in RigVM.

• Add CVar to suppress duplicate anim node slot names warning.

• Add CVar that allows for using MovieScene GUID rather than channel hashing for partial-UAnimSequencerDataModel hash (significant speed-up, downside is MovieScene GUID invalidation is non-deterministic).

• Added additional pose validity checks when getting the target transform of a bone socket references.

• Added additional pose validity checks to ConvertWidgetLocation in FAnimNodeEditMode.

• Reimplementation of "Speed up UAnimSequence::CreateDerivedDataKeyHash" - drastically decreases time spend on Animation Sequence its DDC key generation.

• Added ObjectsSelected delegate interface function to IAnimationEditor.

• Added virtual keyword to FAnimInstanceProxy::UpdateCurvesPostEvaluation.

• Allow Custom Widgets for AnimNotifies.

  • Rename

    • INodeObjectInterface → INotifyNodeObjectInterface.

    • ETimingElementType → ENotifyTimingElementType.

• Allow Custom Widgets for AnimNotifies.

  • Rename

    • INodeObjectInterface → INotifyNodeObjectInterface.

    • ETimingElementType → ENotifyTimingElementType.

• Expose certain solver collision settings to RBAN and RBWC nodes to allow for improved environmental collisions. This gives parity with functionality in control rig physics. Also added a new category for the details panels to clean up the UI.

• Expose Set/Get Accumulated Time in BlendSpacePlayerLibrary.

• Added experimental Animation Layering plugin containing:

  • Copy Bone Motion Anim Node.

  • Copy Bone Advanced Anim Node.

  • Bone Mask Anim Node.

• Added Scoped Crash Data For Animations (Make animation crashes easy to debug).

• Notify States: Added the option to not merge the lifetime of notify states on concurrent plays of the same animation asset.

• Allow for notify event dispatch to be disabled on a per-mesh component basis. This doesn't prevent the notifies from being sampled but the associated events will not be dispatched at the end of animation update when the flag is set.

• Allow priority to be set on transitions to conduits so it's possible to deprioritize them vs transitions to other states.

• Marked GetCurveValueWithDefault() in AnimInstance as const.

• Fixed description of BoneIsChildOf.

• Enable animation frame stripping cvar support in editor Useful for debugging purposes.

• Exposed AnimMontages track properties to BluePrint.

• Offset Root Bone: Added support for teleporting.

• Pose History: Added Blueprint library functions to get bone data from pose history.

• Force property access pre-event graph update callsite to be invoked prior to InitializeRootNode being called. This prevents property access errors coming from anim nodes that call GetEvaluateGraphExposedInputs from Initialize_AnyThread.

• Added standard blend for Anim Graph mirroring node.

• Add user-exposed NotifyInstanceID to FAnimNotifyEventReference. This can be used in user events to tell notify instances apart.

• Added populating the error log with names of missing skeleton bones, when a mesh has bones that do not exist in the skeleton yet.

• Removed no longer used additive total bone weight array from the BlendProfileScratchData and SlotEvaluatePoseWithBlendProfiles.

• Add 'Ignore Pose Asset Source Animation Curves' property to the pose blend node.

• Marked UAnimInstance::GetCurrentStateName as const and added const correctness in function body.

• Add filter for non-additive animations in the animation editor asset browser.

• Removed deprecated functions in USkeleton (GetSkeletonRemapping, GetAssetRegistryTags, CollectAnimationNotifies, GetRawAnimationTrackIndex).

Bug Fix:

• UAF

  • Fixed uninitialized variable ContentOnly in SRigVMFunctionPicker causing state tree function binding regression.

  • Fix: ExecuteBindings_GT not gated by external prereqs added via module dependency traits.

  • Fix for multiple copies of variable instances showing up in rewind debugger for graphs.

  • Fixed check failure on shutdown.

  • Fix for GetHostTransform not reporting the correct value until the actor has moved after spawn.

• Add handling for rare cases where anim sequence memory mapping fails.

• Ensure linked anim instances created by a post-process anim instance are not reset prematurely.

• Fix ABP linked layers crash due to stale node references during cross-asset compilation.

• Fix early check for derived anim Blueprints causing crashes when parent class skeletons were deleted Add update path for derived anim Blueprints when parent skeletons mismatch or are deleted.

• Ensure anim instance functions wait for async animation updates to terminate when called from the game thread.

• Improved Animation Notify track behavior when displayed and used at non-standard DPI level.

• Fix for inaccurate root motion playback on first loop in persona editor.

• Animation Modifiers: Fix for revert and removal when bReapplyPostOwnerChange=true.

• Fixed ensure when opening Animation Sequence containing (additive) transform curve(s).

• Addressed non-deterministic cooking behavior caused by Animation Graph Slot nodes.

• Fix for Constraint AnimNode when initial weight is zero but in the future will be non-zero.

• Fix for crash in Constraint AnimNode when changing setup while running.

• Anim Montage: Fixed prematurely calling of AnimNotifyStates end events when the montage advance is driven by forced positions and their delta is zero (e.g. from a frame-locked Sequencer with unstable frame times).

• Fix missing compatible skeleton conversion when retrieving attributes.

• Get the correct compact pose bone index rather than mesh bone index.

• Fix up missing calls to initialize FK control rig hierarchy when running in lazy init mode.

• Avoid crashing when blend space sample uses a null animation sequence.

• Always preload animation sequence dependencies as MT async loading requires manual handling.

• Fixed crash when updating blend samples in a Blendspace while PIE is running in a separate window.

• Fixed crashes caused by NaN bone transforms coming from AnimNode_StrideWarping.

• Fix for potential NaN bone transforms generated inside AnimNode_FootPlacement if root is rotated exactly 90 degrees from expected approach direction.

• Set anim group follower LeaderScore to always be less than any possible leader, to avoid selecting any follower as leader if there's any leader in the FAnimGroupInstance.

• Fixed ensure in UAnimInstance::TriggerQueuedMontageEvents.

• Skeletal mesh component now refreshes the skeletal mesh asset at PostEditImport, so the skeletal mesh is not lost after a duplicate.

• Fixed crash in DebugDrawSkeleton when using 'show bones' command.

• Validated that users are not trying to apply an anim BP preview overlay to self.

• Move leader component test earlier in CopyPoseFromMesh to make sure our bone map is updated correctly.

• Make SharedContext a unique ptr to force destruction when released in FAnimNode_SaveCachedPose::PostGraphUpdate.

• Fixed issue where Additive and Blend components within an Animation Sharing setup were not locked to LOD0, causing artifacts on non-LOD-compatible target components.

• Fix potential thread-unsafe access to skeleton remapping data. In that case of FReferenceSkeleton, limit when the remapping data is refreshed to only when it's a skeleton and not a mesh that is having it's ref skeleton rebuilt.

• Fixed CopyBonesModifier for bones without pre-existing curves.

• Fix issue with blended curve container not correctly tracking when it is sorted.

• Fix to allow notifies that are sampled via AnimSingleNodeInstance to store the current playback time. This means that UAnimNotifyLibrary functions that rely on the current time can be used on these notifies.

• Enable FBoneSocket Target Pickers in Contexts Outside Anim Montages.

• Prevented crash loading into CitySample using -dpcvars=Editor.ObjectReverseLookupMode=2.

Deprecated:

• Cleaned deprecated methods from animation runtime (up to 5.6).

• Removed non-reflected UE_DEPRECATED items (5.0-5.6) spanning Engine/Source/Runtime/Engine/{Classes, Public}/Animation, Engine/Source/Runtime/AnimGraphRuntime (+ MovieSceneTracks anim nodes), and Engine/Source/Editor/AnimGraph compiler interfaces.

• Cleaned deprecated methods from LiveLink (up to 5.6).

• UAF: Fixed incorrect deprecation logic in AnimNextComponent when loading Blueprints with data inheritance on deprecated variables.

• Deprecated CachedSoftObjectPtr in USkeleton.

Sequencer

New:

• Sequencer

  • Delete Mark is now Delete Selected Marks which allows the selected marks to be deleted at once.

  • Add Mark is now Add Mark at Playhead which adds a mark at the current playhead as opposed to where the mouse was pressed.

  • Playing a sequence in the editor now honors the time bounds (selection range when set, otherwise playback range), matching rewind and key-jump behavior.

  • Playhead scrubbing can now be limited to the selection range, in addition to None and Playback Range.

  • Bake Transform is now available from the object binding right-click menu.

  • Added missing Convert to Spawnable command binding, and route Level Sequence conversions through Convert To Custom Binding so custom-binding spawnables work.

  • Bake Transform now disables the original track instead of toggling each section, matching the Bake to Control Rig behavior.

  • Add support for Material Slots Overlay Material switching and parameter animation. .

  • Assigning a spawnable to an object property now creates an Actor Reference Track automatically, so the reference doesn't go stale when the spawnable's path changes.

  • Component Attachment tracks now respect hierarchical bias, so a higher‑priority attachment section correctly overrides a lower‑priority one when they overlap.

  • The Actor Reference track now supports Completion Mode, so disabling or muting them properly restores the prior reference.

  • Jump to Next/Previous Key now respects looping. When looping is off, it no longer wraps past the first/last key.

  • Add Selection from Content Browser is now a bindable command, so you can assign it a keyboard shortcut in editor preferences.

  • The Actor Reference track (used for properties like the Cine Camera's Look At Target) has been upgraded to Sequencer's ECS evaluation system, aligning its performance and ordering with other tracks.

  • Lighting channels on primitive components are now animatable.

  • Dragging a marked frame now translates selected keys and sections along with it.

  • Pausing the game now pauses the Sequencer clock as well (opt out via Sequencer.AllowPausedClock 0).

  • The back/forward mouse buttons now navigate forwards/backwards through sequences, matching the Blueprint editor's tab navigation.

  • Snap to Markers while scrubbing now snap to the playback start/end and selection start/end frames.

  • Markers are now also selected with Select All in Selection Range, Select Forwards, and Select Backwards. Added a new option to Select Markers in Selection Range.

  • The Add Track button for Subsequences now allows creation of custom Level Sequence subclasses.

  • Remove DisplayName="Anim Sequence" for MovieSceneSkeletalAnimationSection because it conflicts with Anim Sequence assets.

  • Add a way for stitch track to work with Animation Blueprints. This is a bit of a workaround for the issue of pose history not being able to be both read from and written to easily via an attribute, which is necessary for the stitch track. Now, the user can add an 'OverridePoseHistoryName' which, in animation Blueprint mode, will look for a pose history node tagged with that name and pull the pose history from it for use in the stitch track. This allows the pose history node to be _after_ the sequencer target node, which is necessary for blending out to work correctly. In addition, we set up an example properly in the AnimSandbox to show this working.

  • Deselect marked frames when keys and sections are also deselected. Disallow marked frame movement when they are locked.

  • Limit Viewport Selection is now in the viewport menu whenever a sequence is active (was Animation-Mode-only); UMG and Actor Sequence get the button in their own toolbar.

• Anim In Engine: Control Rig use ECS evaluation by default Users can fall back to legacy evaluation with: ControlRig.UseLegacySequencerTemplate true.

• Add SequencerTools toolset for AI-driven sequence creation and editing.

• Added call to Global Dependency Graph update cache in OnAllModuleLoadingPhasesComplete to prevent the graph's cache to update when the first sequence is played. In the event that a plugin/module that mutates this graph loads after OnAllModuleLoadingPhasesComplete, the cache will be invalidated and will be updated when the first sequence is played.

• Sequence Validator: Fixed Whole Section Ranges rule reporting incorrect results.

Bug Fix:

• Sequencer

  • Visibility Track keys are now correctly set with their current values. Visibility is inverted from their Hidden property and the setting of the key was not correctly inverted.

  • Fix FVector2f/3f/4f tracks dropping keys silently UnpackChannelsFromOperational(const FFloatIntermediateVectorand) was writing FMovieSceneDoubleChannel entries, but UMovieSceneFloatVectorSection stores FMovieSceneFloatChannel curves. When keying, the channel proxy lookup returned nullptr and the key was silently dropped.

  • Cooking a project that uses Time Warp tracks inside child Level Sequences no longer fails with an "illegal reference to private object" error.

  • The camera cut tracks which have preroll now take into account the instance transform data of a level sequence which is passed to the streaming manager.

  • Update the possessed object class when matching possessable GUIDs (including ones that bind to spawnables), so bindings no longer hold a stale class.

  • Conditional sections inside a subsequence now evaluate correctly when a parent sequence is conditionally disabled.

  • Sequences with camera rig rails are no longer incorrectly marked dirty on save. Spline components in these camera rig rails are just visualization components, and those don't need to be regenerated or have their physics state be recreated on save.

  • Fixed a RepLayout mismatch from an editor-only field in MovieSceneSequencePlaybackSettings.

  • The entity system threading model is now refreshed at each call site after ScheduleTasks, instead of inside ExecutePhase where it was computed too early.

  • Fix race condition in TEntityTaskComponents::Schedule_PerAllocation Schedule_PerAllocation on TEntityTaskComponents (the unfiltered path) was setting bSerialTasks = false, making it behave identically to Fork_PerAllocation and allowing multiple allocations to run in parallel on different threads. This violated the Schedule_ contract that guarantees serial execution of ForEachAllocation calls. The filtered variant (TFilteredEntityTask::Schedule_PerAllocation) and both Schedule_PerEntity overloads correctly set bSerialTasks = true.

  • Film overlay options menu commands no longer stop working because they were bound to a transient widget that could be destroyed when the toolbar refreshed.

  • Dragging the selection range end with the time slider now sets it as exclusive, matching the playback range behavior.

  • Fixed the inverse sequence transform calculation, correcting subsequence time mapping.

  • Setting the selection range start/end now respects the snap interval.

  • Hide Selected / Isolate Selected with no tracks selected no longer hides or isolates every track.

  • When importing an fbx, tangents are now negated when Force Front X-Axis is enabled, keeping curve shapes consistent under the flipped axis.

  • Spawn template creation now guards against a stale object of a different class occupying the same name under the same outer.

  • Material Parameter Collection tracks no longer lose their derived display name on PostLoad when the stored name was already empty.

  • Renaming a subsequence while viewing through it no longer crashes.

  • Fix bug in ECS Control Rig that left the anim instance in an incorrect state after baking an anim to control rig requiring clicking on the control rig track to get it to work correctly. This was caused by the skel anim system restore state triggering an anim instance reset after the control rig had set the new anim instance. .

  • Remove redundant RelevantComponent from UMovieSceneSkeletalAnimationSystem RelevantComponent was set to SkeletalAnimation in the constructor, which caused IsRelevant() to short-circuit to true whenever any entity had a SkeletalAnimation component, bypassing IsRelevantImpl. This meant the system would get linked even when all skeletal animation entities had the AnimMixerPoseProducer tag, which IsRelevantImpl correctly filters out. .

  • Generating a track/section/key from the keyframe button in the details panel now correctly resolves nested array properties (ie. MyArray[0].bVisible).

  • Bake Transform now gathers key times from all sections of a transform track, not just the first.

  • The Perlin noise menu now uses the display text instead of the raw channel name.

  • OnQueueSubtitles / OnAudioFinished / OnAudioPlaybackPercent delegates are re-bound (or cleared if unbound) when an AudioComponent is recycled across plays.

  • Clicking on the Render Movie button will now respect the Movie Render Queue job type (i.e. Movie Graph).

  • The object binding menu now only traverses bound objects, so spawnable template components aren't accidentally bound to new bindings.

  • Pinning a track no longer swaps the main track area's view model with the pinned area's, keeping the two views properly separated.

  • Removed ALevelSequenceActor dependency from FLevelSequencePlaybackContext.

  • Fixed a bug where conditions were not actually checked in subsequences.

  • Compiling a Blueprint while a sequence is open no longer triggers a pre‑animated state restore that could race with async loading.

  • Defer outliner reparenting that previously happened mid-iteration, fixing potential instability.

  • Toggling Net Addressable Name on a spawnable now sticks. It's no longer reset every time the object template saves.

  • Property bindings that resolve to a non‑existent array element are now flagged as invalid, instead of silently failing or evaluating against stale data.

  • Camera Cut tracks set to "Keep State" now restore to the correct view target on repeat playback, and Keep State sections following Restore State sections keep animating their properties instead of snapping back when the prior section ends.

  • Tracks that rely on cleanup callbacks (like Control Bus modulation on audio tracks) now release their resources correctly when you close Sequencer after a Play-In-Editor session.

  • Editing a property on a character's mesh component in Sequencer no longer snaps its animation pose back to the reference pose. The pose now updates correctly whether you select the actor or the mesh first.

  • Skeletal mesh animation pose no longer resets when you edit a property on a component (subobject) of the actor.

  • Fixed not being able to set just the X, Y, or Z channels of a transform for a skeletal mesh.

  • Camera Cut and Cinematic Shot thumbnails only update during PIE when the PIE world is the one bound to Sequencer, so MRG/MRQ runs don't spuriously refresh them.

  • Fix issue with baking code (and other code) that uses FindSpawnableObjectTemplate in the case that the guid passed in is a possessable that is possessing a spawnable in another sequence. We now check for that.

  • Fix crash when closing Sequencer during deferred modification flush We do this by suppressing the deferred modification flush events during the destructor.

  • Fix crash when compiling sequences with null tracks Runs 'RemoveNullTracks) before calling CompileTrack() to prevent crashes when a sequence contains null track references. We need to track down what is causing tracks to be null, but this should fix the crash as it currently exists.

  • Fix Control Rig ECS crash that happens with dynamic rigs that change the control rig channels mid evaluation. To fix this we hold a hash of the channel list in the control rig component data and if it changes we re-copy the channel pointers into the ecs component or unlink if channels no longer exist. .

  • Sections with no channels are again considered keyable (regression fix for keyable detection).

  • Fix crash when keying non-object properties in ObjectPropertyTrackEditor Adds a check to make sure the property is actually an FObjectPropertyBase before calling GetPropertyValue(). This prevents a crash when a non-object property is incorrectly routed to this track editor, as the type size assertion in GetPropertyValue would fail. fix animation/sequencer.

  • Delete Channel no longer fails to delete when only the first name in the path matches. It now matches the last name in the path which is the actual channel name.

  • Splitting or trimming a section now places boundary keys with the correct values and preserves each key's original interpolation type, so a linear curve stays linear instead of being forced into a cubic S‑curve.

  • Fixed crash when a level sequence has a null track.

  • Fixed a crash that could occur when evaluating sequences with transform origins gathered from multiple subscenes in parallel.

  • A Template Sequence section's Hierarchical Bias now initializes before config can overwrite it, so per-section overrides stick instead of inheriting the config default.

  • The viewport no longer jitters when the aspect ratio is animated.

  • Sequence players set to loop now remember their loop count after playback ends. Restarting a looping sequence plays as a loop instead of playing once and stopping.

  • Camera Cuts and other pinned tracks no longer disappear from the timeline when dragged into a folder. Sequencer now blocks drops into folders with a mismatched pinned state and shows no drop preview.

  • The time-display UI now refreshes after subsequence nested transforms update, so local time reflects the current context instead of the previous one.

  • Editing the Level Sequence Actor's Transform Origin now marks the sequence dirty so the editor re-evaluates it.

  • Whether using anim Blueprints or custom mode, the previous anim instance gets force re-initialized after sequence is over, potentially resetting data stored in the AnimInstance unnecessarily. Previously this would only occur if the skeleton changed, but we attempted to address an issue where if Custom Mode was used, the previous anim instance was getting uninitialized anyway, and would now be stuck in an uninitialized case. That fix was a bit overzealous however, as this forced re-initialization was even occurring for cases where animation Blueprints were used and we weren't switching anim mode or anim instances. This change only re-initializes if Sequencer changed (and is now restoring) the anim instance.

  • Fragment type strings for the Universal Object Locator are now encoded/decoded so characters that are illegal in object names survive serialization.

  • The audio track no longer crashes when its played from an Actor Sequence.

  • Dragging the time range slider now properly accounts for display scaling on the desktop.

  • Resolving setter functions for bool properties now strips off the leading 'b' (eg. SetVisible matches the bVisible property).

  • Sequencer no longer expands procedural channels (like Perlin noise) to the keying time when adding keys to neighboring channels. Noise tracks keep their original length.

  • Audio in Sequencer no longer restarts incorrectly when the playhead jumps, and audio that was paused or stopped stays paused instead of being restarted by a forced time‑sync.

  • Control Rig: Fix Sequencer space channel evaluation in ECS path , [at]benoit.gadreau.

  • Fixed crash on EndPlay when using a Sequencer that contains a Spawnable ChaosCacheManager.

  • Sequencer Media track: Drag/drop of media onto a track no longer crashes.

  • Sequencer ECS Control Rig: Fix issue where additive section weights were getting double-applied. The code didn't quite match the old eval template- we need to only apply weight to absolute sections since it already is getting applied to additive sections via the parameters themselves getting weight applied.

  • Sequencer Scripting: Add Key In Channel now honors the Sub Frame argument when Time Unit is Display Rate.

  • Sequencer Control Rig: Fix issue where if multiple parameters with different types have the same name it can prevent the right parameter from being keyed. [at]ue-sequencer

• Re-added logic to handle Pasted Actors when pasting bindings.

• Fix to ensure that control rig shape actor is parented to the root component of the actor it is driving. This prevents circular dependencies for actors that don't have the root component as the default attachment component when a control rig is then attached to them.

• Movie Scene: Fixed issue where zero-scaled components would get their render state dirty called every time UE::MovieScene::SetComponentTransform is called.

• Fix for when an animation instance is a post process anim instance that is being evaluated we would fail to verify if it has changed because we don't check that it is post process. This marks the sequence as dirty and triggers the spawning phase to happen every frame. Now we validate against post process animbps as well.

• UAF Root Motion Extraction fix Move the same checks we do in the old code regarding 'Force Lock Root Bone' to allow root motion to still be extracted.

• Fix various issues where the normalized view did not always draw its curves correctly.

• Fixed visibility system to define implicit prerequisites only for the CDO. Additionally FSystemDependencyGraph::MakeRelationship only increments serial number if an edge was truly added to safeguard against situations where MakeRelationship gets called for the global dependency graph outside CDOs.

• Fix an issue where some curve types failed to draw the curve line before the first visible key correctly.

• Cine Camera: The Sensor Aspect Ratio is no longer animatable since its value is derived from Sensor Width and Height.

Skeletal Editing

New:

• Skeletal Mesh Editor

  • Explicit Asset Save action also applies pending changes to the asset before saving to disk.

  • Ported Bake Vertex Color tool from Modeling Mode.

  • Changing from one tool to another no longer requires pressing the accept button, multiple tool changes are cached and bulk committed only when users explicitly press apply changes to asset.

  • Added various menu options in the Morph Target Viewer to edit and manage morph targets, including mirror/flip/merge/apply current weight and several others.

  • Added geometry selection support for Morph Target editing, which allows for vertex level transform, soft selection and geometry isolation.

  • Added support for bone weight locking to Edit Skin Weights Tool.

  • The Skeletal Mesh Editor now shows a linear color ramp instead of an array of colors.

  • The Skeletal Mesh Editor now has a dedicated menu in the asset editor viewport toolbar.

• Skeletal Mesh Morph Target Editing Tools

  • Added Mask Morph Target Tool, which applies a custom mask to the editing morph target.

  • Improved Move brush in Sculpt Morph Target tool such that it is non-accumulating and easier to control.

• Improve copy-pasting and duplicating bones.

  • Add new options to Paste Local and Paste Global.

  • Pasting bones now retains the hierarchy of pasted bones.

  • Pasting bones now pastes copied bones and their children.

  • Duplicate now retains the hierarchy of duplicated bones.

• Added Dataflow based workflow to reimport a skeletal mesh from mesh and preserving all existing attribute and morph targets.

• Added a Dataflow Template for Skeletal mesh that takes a static mesh, split it by its mesh islands and convert it to a skeletal mesh where each mesh island is rigidly skinned to a separate bone.

• Skeletal Mesh Modeling Tool: Added "Import Bones from Assigned Skeleton" menu option to Edit Skeleton Tool.

• Added two Dataflow templates for skeletal meshes : Skeletonizer and Subdivision.

• New hotkey Alt-B to toggle draw bones.

• Add Dataflow support for Skeletal mesh asset.

• Skeletal Mesh Modeling Tools: Added support for cotan edge weighting in Edit Skin Weights tool.

• Skeletal Mesh Editor and Modeling Mode: A new version of the paint maps tool is enabled by default, to revert to the old version, use cvar "ModelingTools.UseExperimentalMeshAttributePaintTool 0" and re-enter the editor mode.

• Ctrl-clicking the selection mode buttons in the skin weight tool now converts selection from one mode to another.

• Mirroring now replaces strings from the right, finds strings anywhere in the name and supports regular expressions.

• Added a Clear() method to USkeletalMesh, to help prepare a USkeletalMesh for re-use w/ entirely new mesh/skeleton/etc data.

• Added Blueprint functions to selectively remove morph targets and skin weight profiles from a skeletal mesh.

• Orient bones now orients bones with multiple children in parent orientation.

• Switching between the isolated and the full mesh no longer clears the selection when editing weights.

• Selecting in the list of weighted Bones in the Weight Tool now selects the Bone in the Skeleton Tree.

• Improve selecting affected vertices of a Bone when Shift- or Ctrl-clicking the Affected button when editing Weights.

  • Fix Shift- and Ctrl-clicking Affected sometimes had no effect.

  • Ctrl-clicking Affected now toggles the selection of the affected vertices of a bone.

• Mirror and Orient no longer show an obsolete none axis option.

Bug Fix:

• Skeletal Mesh Modeling Tools

  • Add accumulation support for Relax brush in Edit Skin Weights tool and Paint Maps tool.

  • Fixed data loss when making skin weight edits to vertices holding 12 bone influences.

• Clear stale thumbnail scenes on asset reload.

• Avoid crashing when skeletal mesh reference skeleton changes by invalidating mesh linkup cache.

• Skeletal Mesh Editor: Fixed add support for previewing morph target curves in addition to bone pose in skeletal mesh editor when using the "Running Instance" preview controller in preview scene settings.

• Fix a crash where transient meshes with no mesh description are opened.

• Skeleton tree views now retain their selection and expansion state after edits.

• Bones are now mirrored in global space instead of the first parent's space.

• Collapsing nodes in the skeleton tree no longer deselects children of the collapsed node.

• Fix an issue where the wrong bone was renamed when a name was committed by changing the selection and losing focus.

Audio

New:

• Waveform Editor

  • Playhead refactor to use frame positions to allow better precision, along with handling offscreen playhead positions. Playhead is not rendered when offscreen.

  • Snap to zero crossing shortcut Integrated from 39.00.

• Sequencer

  • Update audio sections to not auto expand to keyframes.

  • Control bus mix track.

  • Audio control bus track.

• Adding db and Decibels to DefaultEngine.ini so it's possible to use UProperty markup for Units.

• Unclamping the "VolumeBase" metasound input for both oneshot and looping metasounds exposed to UEFN.

  • Tooltip reads as "[-60, 12] - Base volume applied to the sound, in decibels. The default value of [0] results in no volume change. A value of [-60] results in silence. [12] is the maximum gain we can apply."

  • VolumeBase default input range now reflects the new clamp range.

  • The clamped range is now [-60, 12] to match the clamp of audio devices. Previously was [-60,0] Updated tooltip to reflect this change in clamp.

• Unified property UX across Attenuation, AudioBus Sends, and Submix Sends.

• Submixes are now ref-counted when using the register/unregister API. When no longer referenced, submixes will be removed from the root. This can be disabled by setting au.RemoveSubmixesFromRoot to 0.

• Movie Render Queue: Expand ability to choose submix to export.

• Added option in CommonButtonGroupBase to suppress button sounds when calling SelectNextButton or SelectPreviousButton.

• Subtitles: Enable resizing of subtitle sections in sequencer.

• Unified property UX across USoundBase/USoundWave/USoundCue/UMetaSoundSource.

Bug Fix:

• Animation Editor

  • Animation Editor and Level Editor Viewports now call UpdateAudioListener when they receive focus and when the perspective camera moves. The Animation Editor has an additional call when we focus on the preview mesh. This fixes the requirement to move the camera in the viewport editor before the audio listener position updates.

  • Animation Editor windows request a new Audio Device so that we don't share the same Audio Device with Level Viewports.

• Sequencer

  • Fix for input channels not resetting when a metasound is changed.

  • Fix MRQ non realtime render to render silence instead of disabling.

  • Fixed sequencer audio channel inputs updating when modifying a metasound asset.

• Disabling Hardware Convolution Reverb on PS5.

• Add CQTest coverage for SoundFieldRendering encode/decode/rotation.

  • New SoundFieldDecoderTests.cpp with 22 test methods across 6 test classes.

  • Tests FAmbisonicsSoundfieldBuffer (construction, reset, duplicate).

  • Tests FAmbisonicsSoundfieldSettings (unique ID, duplicate).

  • Tests FSoundFieldDecoder with both omnidirectional and directional FOA inputs.

  • Tests directional decode correctness: Verifies spatial energy distribution matches source azimuth for stereo and quad speaker layouts.

  • Tests FOA rotation: Energy preservation, W-channel invariance, Y/X channel shifting under yaw rotation, and decoded balance shift after bed rotation.

  • Tests FSoundFieldEncoder channel counts (FOA/2nd order) and directional content.

  • Tests encode/decode roundtrip: Energy preservation, directional bias retention, and silence passthrough.

  • Tests public API: Format name and default settings.

  • Updated AudioCQTests.Build.cs to add SoundFieldRendering and AudioExtensions module dependencies.

• Waveform Editor

  • Fix for waveform editor playhead snapping to proper trim start or end bounds when editing

  • Fix playhead snapping when editing trims to snap to appropriate trim start or end bounds.

  • Fixed an issue in the Waveform Editor where wave files containing a partial final sample block were loaded with invalid trailing bytes, causing corrupted playback. The invalid bytes are now silently truncated at load time — the raw asset data is not modified.

• Fix for MRQ to render silence when there is no audio to allow timing of sequences to line up

Architecture

New:

• Change SubmixEffectReverb default Gain from 0.0 to 1.0 for new assets.

• Adding optional Low pass and High pass filters to submix and audio bus sends.

Bug Fix:

• Fixed issue where SoundBase→bEnableSubmixSends being false would ignore attenuation submix sends.

• Crossfade dry signal against submix effect chain overrides when no base chain absorbs the gap.

• Fix FDelay incorrect output for sub-1-sample delays.

• Fix potential thread-safety races in vorbis DLL init and AudioFormatOgg singleton.

Deprecated:

• FSoundWaveProxy now acts as a broker for FSoundWaveData so consumers can optionally update to latest data (i.e. post asset re-import). This requires the deprecation of FSoundWaveProxy that was just forwarding calls to the FSoundWaveData.

MetaSounds

New:

• Adds the experimental MetaSound Channel Agnostic Types (CAT) Wave Player node and its supporting types under the MetasoundExperimental plugin.

  • Engine runtime

    • UCatSoundWaveContainer + FCatSoundWaveContainerEntry: a UObject container of weighted USoundWave entries, edit-time UI for designers.

    • FCatSoundWaveContainerProxy / FCatSoundWaveContainerData: audio- thread proxy snapshot of the container, doubles as Audio::ISoundWaveContainer.

    • Audio::TCatProxyView: lock-free linked-list base for the proxy, supports mid-render hot-swap of container state from the game thread to the audio render thread.

    • MetasoundCatExperimental::FSoundWaveContainerAsset: MetaSound data- type wrapper held by value on the audio thread; namespace-scoped to avoid collision with the Polyphony plugin's same-named asset type.

    • MetasoundCatWavePlayerNode: polyphonic Audio Wave Player. Outputs a polymorphic CAT audio reference resolved at bind time per the Format / Auto / SourceAuto chooser. Configurable max voices, Index / Sequence playback types, Standard / Random playback modes. Sequence mode supports start index, finite/infinite loops, and reset trigger plus per-stage trigger outputs. Random mode supports weighted selection, deterministic seed, and an avoid-recent-N window. Pitch shift via plain float input pin.

  • Editor

    • AssetDefinition_CatSoundWaveContainer + factory: New-asset and "Create Sound Wave Container" content-browser context menu on SoundWave selections.

    • Editor module wires the MetaSound graph-pin factory registration for the new data type. MetaSound Engine / Frontend prerequisite edits.

    • UMetaSoundSource::CalculateAutoSourceFormat: rewrite to walk RuntimeInputData parameters with InParams overrides and pick the greatest channel count among Object / ObjectArray inputs. Adds a checkf guard requiring RuntimeInputData to be cached before the call. Intentional behavior change in scope of this change.

    • MetasoundFrontendSourceInterface: removed the unused AudioMixerNumChannels extern. The API never shipped, so no deprecation shim is required.

• Retain MetaSound input values on presets when parent graph inputs are renamed.

• Make MetaSound preset reset to default use inherited parent values.

• Improvements to the MetaSound node update transform API for C++ node developers New biquad node bandwidth default value for new nodes to avoid DSP edge cases.

• MetaSound DynamicInterfaceNodeConfiguration: Built-in node configuration for sub-interfaces and variants.

  • Add FMetaSoundDynamicInterfaceNodeConfiguration, a generic FMetaSoundFrontendNodeConfiguration that automatically handles sub-interface instance counts and variant type selection based on a node's FClassInterface definition. This eliminates the need for custom per-node configuration structs for nodes that use sub-interfaces or variants.

  • Changes:

    • Add MetasoundDynamicInterfaceNodeConfiguration (Frontend) - core configuration struct that reads FSubInterfaceDescription and variant descriptions from the FClassInterface to drive the node's interface override.

    • Add MetasoundDynamicInterfaceNodeConfigurationCustomization (Editor) - details panel customization providing variant type dropdowns and sub-interface count controls.

    • Update MetasoundExampleWeightedSumNode to use the built-in base configuration, removing the custom FMetaSoundExperimentalExampleWeightedSumNodeConfiguration workaround.

    • Update node registration macros and graph builder for dynamic interface configuration integration.

    • Add engine tests for configuration logic and UI customization.

• Added MetaSound Input Browser for bulk viewing and editing of MetaSound input values.

• MetaSounds that are sent a StartTime input parameter but do not implement the UE.Source.StartTime interface will now only warn once instead of on every play.

• Native MetaSound nodes can define a custom icon and color.

• Enable relative render cost by default Add cvar for logging a sound's relative render cost exceeding a threshold.

• Add MetaSound asset action for fixing up duplicate class name issues.

• Improved MetaSound builder Blueprint API and editor builder listener support for pages.

• Added various options for easy node creation when dragging assets into the MetaSound editor.

Bug Fix:

• Fix MetaSound input widget settings getting overridden when set to a type other than editor preference default.

• Fix crash when au.MetaSound.Experimental.OperatorPool.SetMaxNumOperators is set via Console Variables: In *.ini.

  • The cvar was registered as an FAutoConsoleCommand, but Console Variables: ini parsing creates placeholder IConsoleVariables for any name it encounters. When the MetasoundGenerator plugin later registered the command with the same name, FConsoleManager::AddConsoleObject hit a fatal log: 'Console object named... can'\''t be replaced with the new one of different type!'

  • Convert the registration to a TAutoConsoleVariable, default -1 (leave the pool default unchanged). An OnChanged callback forwards the value into the operator pool. StartupModule applies the current cvar value once the pool exists, so values set from the ini before the module loads still take effect.

• Fix AD Envelope attack phase skipped when Attack Time driven by Value (Float) node with Init Value of 0.

• Fix AB/BA potential deadlock between FOperatorPool::CriticalSection and OnAudioDeviceDestroyed.

• Make trigger repeat node high precision so it doesn't drift compared to Quartz / DAWs.

• Fix MetaSound preset input nodes not respecting sort order.

• Fix crash when setting a MetaSound constructor input or output to an unsupported type (ex. Trigger).

• Fix editor display issues when renaming MetaSound inputs or outputs.

• Fix ensure when reloading MetaSound externally added and referenced by another asset.

• Fix MetaSound patch details panel showing blank output format row.

Sequencer

New:

• Audio Sequencer

  • Added a "Play Until Finished" option to Audio Sections in Sequencer. When enabled, the section's evaluation range extends past its visual end to the sound's natural duration, keeping volume and pitch keyframes, pause, and state-restore cleanup active throughout the tail. Enable it with the CVar Sequencer.Audio.UsePlayUntilFinished (defaults to off).

    • Note: Trimming or resizing a section to a shorter length automatically disables the option, SoundCues that contain Random or Branch nodes are not supported, and MetaSounds extend to the sequence's playback-range end and stop via their OnFinished callback.

  • Added a bRepeating property to UMovieSceneAudioSection to replace the semantically overloaded bLooping property. The new property accurately describes Sequencer behavior by restarting a one-shot sound at the section boundary when the section is longer than the sound, reserving the term “looping” for natively looping audio assets. The transition is controlled by the Sequencer.Audio.UseRepeating CVar (enabled by default), and existing assets are migrated automatically on load.

  • Fixed a bug where loop-divider lines in the Sequencer timeline stayed at their original screen positions instead of moving with the audio section when it was dragged.

  • Fixed an issue where audio sections defaulted to looping when added to a sequence, regardless of the source sound asset's loop setting. Audio sections now initialize their loop state from the source asset.

• Batch editing and highlighting for stale actors in audio sections when right clicking on track to batch edit, or multi selecting audio sections. Enable highlighting with cvar au.OutlineAudioActorAttachments.

Bug Fix:

• Fixed a bug where audio sections with a number of float parameter inputs that was an exact multiple of 9 silently dropped all float input data at runtime. Affected sections appeared to play correctly but none of their float parameter automation took effect.

Subtitles

New:

• Waves with Subtitles attached as UserData will now automatically play and stop their subtitles when the Waves are played from inside another Wave, such as a MetaSound or SoundCue.

• When scrubbing through a Sequence with subtitles, the subtitles will now display in the editor viewport.

• Sequencer Subtitle sections initialized with a blank subtitle are now given a default duration of 3 seconds.

• The Subtitles plugin will now warn if you try to replace the UMG widget with an invalid or missing asset.

• Added an optional Border UI element to subtitle UMG widgets' TextBlocks.

• SRT/SubripText files can now be used for bulk Subtitle import. A freshly-imported SRT file will create a Basic Overlay asset, which can be right-clicked to select Convert Basic Overlays To Subtitles.

Bug Fix:

• When loading a Subtitle asset in the editor, it will now enable/disable editing its Duration parameters based on its DurationType.

WaveForm

New:

• Waveform Editor

  • Changing the Fade handle icons and making the colors more colorblind friendly.

  • Decoupled fade in and fade out from the trim transformation. Fade behavior is now controlled by a standalone UWaveformTransformationFade sub-object on UWaveformTransformationTrimFade, making fades configurable independently of trimming in the Waveform Editor.

Bug Fix:

• Waveform Editor

  • Fixed an issue where pressing Shift+Space to return the playhead to the start of a waveform did not reset the playback start position, causing the next playback to begin from a stale offset instead of the beginning of the active region.

  • Fix crash when deleting an open SoundWave asset with the editor open/minimized. Guard USoundWave modification in ~FWaveformEditor() when the editor is closed due to asset deletion.

  • Sound Wave: Fixed an issue where opening a Sound Wave asset in the Waveform Editor while the asset was playing in the editor stopped playback. Transformation edits now take a targeted path in USoundWave::PostEditChangeProperty() that rebuilds compressed data without freeing audio resources for in-flight sounds.

  • U Sound Wave: Adding LUFs and PeakLoudness to metadata in the content browser. When the Waveform Editor is enabled, audio analysis is triggered in 3 spots:

    • On asset import/reimport (per asset).

    • When opening an asset in the Waveform Editor (per asset).

    • Using the ResaveSoundWaveLoudness commandlet.

Editor

New:

• PCG

  • Moved UPCGManagedResource management out of UPCGComponent and into FPCGManagedResourceContainer.

    • Reduces code duplication for new execution source types.

  • PCG Builder Volume.

    • Editor only actor used to limit the bounds of generation when using the PCG Builder commandlet.

  • Blueprint : Point loop functions can require game thread execution (single threaded).

    • This will cause errors if the Blueprint element itself is not 'bRequiresGameThread'

  • PCGGraphExecutionRegistry

    • Now possible to register execution source providers through a common registry.

    • Use this registry to gather execution sources to display in Graph debugger.

    • Implement a default provider for UPCGComponent and UPCGDefaultExecutionSource.

  • More work to move from UPCGComponent to IPCGGraphExecutionSource.

    • FPCGActorComponentMapping renamed to FPCGTrackingManager.

    • Move most of the API to IPCGGraphExecutionSource except for partitioning.

    • IPCGGraphExecutionState already supports partitioning in its interface but actual implementation is still very much APartitionActor dependant (needs to be abstracted away).

    • Some of the partitioning API was moved to IPCGGraphExecutionSource but implementers should not expect functional tracking for anything other than PCGComponents.

• Added a batch processor framework for running functions on large datasets - typically of assets.

  • Results will be written to Saved/MultiprocessResults/results.txt, the location of results can be overridden with the `-resultsfile=` option. -numworkers= can be used to control the number of workers used to process the batch.

  • The Batch Process facilitates parallelism which is useful when invoking a function a large number of times (e.g. tens of thousands or millions). Batch jobs can also be started from script using `BatchProcessLibrary::RunBatch`.

  • Here's a complete example in python - note the final steps regarding registration ceremony:

    Python

    # Save in /Game/Content/Python/snapshot_assets.py import json import os import unreal # Declare a uclass with a function that we want to run, this simple function just # takes an asset path, loads it, stringifies it, and writes the string to a file: @unreal.uclass() class SnapshotAsset(unreal.Object): @unreal.ufunction(params=[str]) def snapshot_asset(self, asset_path: str) → None: # Load the asset: asset = unreal.load_asset(asset_path) if asset is None: unreal.log_error(f"FAIL: {asset_path} (asset not found)") return json_str = unreal.JsonObjectGraphFunctionLibrary.stringify([asset.get_package()], unreal.JsonStringifyOptions(unreal.JsonStringifyFlags.FILTER_EDITOR_ONLY_DATA)) # Build a nested output path from the package path, stripping the leading '/'. # e.g. "/Game/Baz/Foo" → "Game/Baz/Foo.json" and write to that file: relative = asset_path.lstrip("/") out_path = os.path.join(unreal.Paths.project_saved_dir(), "SnapshotAsset", f"{relative}.json") os.makedirs(os.path.dirname(out_path), exist_ok=True) # Write out the stringified asset: with open(out_path, "w", encoding="utf-8") as f: f.write(json_str) unreal.log(f"PASS: {asset_path} → {out_path}") # Discover all assets of the specified type, run snapshot_asset def _run_snapshot(asset_class: str)→ None: registry = unreal.AssetRegistryHelpers.get_asset_registry() registry.wait_for_completion() asset_filter = unreal.ARFilter(class_names=[asset_class], recursive_paths=True, recursive_classes=True) asset_paths = [str(a.package_name) for a in registry.get_assets(asset_filter)] # Build the job description. job = { "function": "/Game/Python/snapshot_assets_PY.SnapshotAsset:snapshot_asset", "arguments": [{"asset_path": p} for p in asset_paths], } # Run the batch — blocks until all jobs complete. results_json = unreal.BatchProcessLibrary.run_batch(json.dumps(job), num_workers=8) results = json.loads(results_json) passed = [r for r in results if r["Passed"]] failed = [r for r in results if not r["Passed"]] print(f"{len(passed)}/{len(results)} passed") for r in failed: print(f" FAIL: {r['ArgumentSummary']}\n {r['Output']}") def run_blueprints_snapshot() → None: _run_snapshot("Blueprint") if __name__ == '__main__': # critical, prevents forkbomb if init_unreal is used to import this script run_blueprints_snapshot()

    Copy full snippet(1 line long)

  • The final step is to register the SnapshotAsset class with Unreal Engine. Typically this is done by adding `import snapshot_assets` to your project's init_unreal.py. Once that is complete you can run the script like any other python script:

    Command Line

    UnrealEditor.exe "D:\Path\To\Your\ProjectName.uproject" -run=pythonscript -script="D:\Path\To\Your\Project\Content\Python\snapshot_assets.py"

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  • To launch a batch job from the command line use: `UnrealEditor ProjectName -run=BatchProcessCommandlet D:\Path\To\Jobs.json` where Jobs.json describes a function and list of arguments to invoke said function with, e.g.:

    Shell

    { "function": "/Script/Engine.KismetSystemLibrary:PrintString", "arguments": [ { "InString": "Hello World", "bPrintToLog": true }, { "InString": "Hello World2", "bPrintToLog": true } ] }

    Copy full snippet(1 line long)

• Added reset to default support for root properties of Editor Preferences, Project Settings, Keyboard shortcuts.

  • Added default value in the tooltip of the property/keybind name.

  • Added CVAR to refresh cached default values : SettingsEditor.ClearObjectDefaultPropertyValuesCache.

  • Limitations are the following:

  • It will not work for properties that are missing the Config specifier.

  • It will not work for custom added rows obviously.

  • It will not work for settings object with a customization since it overrides the default one.

  • It will not work on nested properties, only the root properties of a settings object are supported for performance to avoid having to parse the default stringify value recursively.

• Added ability to search for CVAR, KEYBIND, CONTEXT in Editor, Project, Input Settings.

  • Added keybind button to start listening for key presses and search for these input chords.

  • Simplifying editor settings keybind list by removing description based on command tooltip, description is available in the tooltip now.

• Added behavior selection for tabs navigation action in Editor Settings / Misc, before this change editor only navigates between assets and uses last access time to determine order, now browser style tab navigation is available, it uses window tab order (default is browser style behavior) CTRL+Tab goes forward, CTRL+SHIFT+Tab goes backward.

  • Added an option to hide tab navigation popup dialog widget and directly perform the action (default is showing this dialog).

  • Before this change navigation only worked on asset tabs, you can now navigate between any tabs (editor settings, project settings, logs...).

  • Reduced size of items in tab navigation dialog widget.

  • Fixed Scrollbar not working and Listview not scrolling into view.

• Added UnrealAssetStringify: A standalone program to quickly print a.uasset or.umap to json. Use Engine\Source\Programs\UnrealAssetStringify\BuildScripts\UnrealAssetStringifyInstall.bat to build the tool and optionally associate it with the asset diff command in p4v. Once built the tool can be found at Engine\Binaries\${PLATFORM}\UnrealAssetStringify[.exe] Example usage:

  • `UnrealAssetStringify.exe "D:\Path\To\A.uasset"`: Prints the asset to stdout.

  • `UnrealAssetStringify.exe --save "D:\Path\To\A.uasset"`: Writes the json to Engine\Programs\UnrealAssetStringify\Saved

  • `UnrealAssetStringify.exe --save="D:\Output\A.json" "D:\Path\To\A.uasset"`: Writes the json to "D:\Output\A.json" instead of the default save location.

  • To open a.uasset for viewing in vs code use Engine\Source\Programs\UnrealAssetStringify\Scripts\UnrealAssetStringifyOpenAsset.bat.

  • To manually diff uassets using p4v use Engine\Source\Programs\UnrealAssetStringify\Scripts\UnrealAssetStringifyP4VDiff.py.

    • UnrealAssetStringify is a read-only tool that is useful for reviewing asset changes, post mortem analysis, and asset content indexing; it cannot be used to update uassets.

• Added copy all info to clipboard in project badge context menu.

• Improved material editor preview mesh material slot picker to persist user choice in config, default is material slot 0 active.

• Migrated some common reference validation logic to UAssetReferencingPolicySubsystem::ValidateAssetReferences It now supports:

  • Denoting whether a missing reference is actually missing or only unsaved.

  • Optionally also validating references to C++ modules in plugins (when 'AssetReferencingPolicy.CheckForIllegalCppRefs' is enabled).

  • Ignoring missing references from a redirector, as they may redirect to unloaded plugins.

• Promoted "Slate.bAllowThrottling" to Editor Preferences, which allows real-time property edits when disabled.

• Make the "open source code" action async, so that the editor doesn't lock up every time you press it and wait for your IDE to open.

• Downgraded error handling when a console variable was not found from fatal to error in DeveloperSettings::ImportConsoleVariableValues.

• Added new grid floor material to newly created profile and engine profile as long as they don't have the floor material overridden.

• Change the IOS preview options in order to mirror Android preview.

• Added command with keyboard shortcut to Capture Thumbnail for asset in the Content Browser (CTRL+SHIFT+T).

• Rename ToggleFeatureLevelPreview to TogglePreviewPlatform Rename IsFeatureLevelPreviewEnabled to IsPreviewPlatformEnabled Rename IsFeatureLevelPreviewActive to IsPreviewPlatformActive.

• Merged ToggleFeatureLevelPreview into SetPreviewPlatform using a new bCompileShaders parameter that controls whether or not we compile the shaders.

  • Added bRestore parameter to device profile update to skip redundant RestorePreviewDeviceProfile during toggle.

  • Removed CachedEditorShaderPlatform member, using GMaxRHIShaderPlatform directly.

  • Removed toggle button restriction for GMaxRHIFeatureLevel.

• Added in-editor validation for missing hard-refs This is disabled by default, but can be enabled by setting the CVar 'AssetReferencingPolicy.CheckForMissingHardRefs' to true.

• Editor Preview Platform Optimizations Materials are already updated by SetPreviewPlatform, so disable the automatic per-texture material dependency update 8min →1min Preview transition.

• Improved support for incremental validation in incremental cooks.

  • Incremental cooks already mostly handle incremental validation, as they skip loading the package if it hasn't changed (as validation runs via UCookOnTheFlyServer::LoadPackageInQueue), however changes to a world would still validate all their external objects. This can be quite slow for large worlds.

  • This change improves the incremental validation support so that it only validates the specific external objects that have changed in a world being re-cooked. It does this by comparing the hash of each external actor object against the previous version that was validated, and skipping any that haven't changed.

  • This feature is disabled by default, but can be enabled by setting the CVar 'cook.validation.IncrementalExternalPackageValidationEnabled' to true.

  • Note: It only currently works for single-process by-the-book cooks. You can also now trigger a full revalidation when running incremental validation against a new build version, by setting the CVar 'cook.validation.IncrementalValidationRequiresSameBuildVersion' to true. This is disabled by default.

• Added ConfigureCookSession event, to allow registering extra artifacts and collectors to be used by the cooker.

• Fixed level editor PlayFromHere action not working with keybinds (set to ALT+SHIFT+P).

  • Improved API to play from here based on click, selected actor or custom position.

  • Play mode (Floating window or in viewport) will be based on the selected user choice in Play Settings.

  • Play from here will first check selected actor (must set bCanPlayFromHere to true) then fallback to viewport last clicked location.

• Selection: Typed Element Common actions now supports a CanDuplicate so asset editors can customize if they allow for duplicating of the selection.

• Add support for capturing expansion state per custom built details view via ViewIdentifier's.

  • Initial usage example in SStateCentricViewMainStateNode.cpp.

• Scene viewports can now compute correct mouse positions in cases where the underlying scene render is a different resolution from the Slate output of the viewport.

• Make "new-process" PIE work like "Preview Platform"

  • Mobile "new-process" PIE now respects the Preview Platform set, the Device Profile and the Aspect ratio(flipped, unflipped) of the main editor viewport.

• Add Aspect Ratio to IOS Preview Json.

• Revision Control: Revision control helpers get status functions can now use the cached file state. This can be useful after operations that already update file state (i.e. saving files).

• Minor Improvement of Log Categories performance in the OutputLog.

• Add Preview json Versioning.

• Add Flip Aspect Ratio for Preview Json.

• Add ConfigRules to Android Preview Json Clean-up unnecessary usage of FName in AndroidDeviceSelector.

• Preview Json Improvements.

  • Added IosPreviewDeviceProfileSelectorModule in order to enable Generate/Preview Json on IOS.

  • The DeviceSelectors will now return the PreviewPlatform from the DeviceProfile selected and the device properties.

  • Modified the way the Preview Json preview platform label name is shown. It now displays Preview Platform Name + Device Profile, instead of just Device profile.

  • Confirmation Dialog added when Generating Platform Json.

• Add Editor Settings to configure default name with prefix and suffix for new assets.

• Added shaderball as a mesh preview in the material editor.

  • Save the last used preview mesh in config to load it again on material and material instance editor opening.

  • Materials will use their own preview mesh property if set, otherwise fallback on the last used editor preview mesh, when the last used preview mesh can't be loaded, falling back to the sphere mesh.

• Added keybind to toggle the grid in Asset Editor (ALT+SHIFT+G since ALT+G is used for perspective view and G is used for GameView).

• Add Control + Shift + Z as an alternate InputChord for Redo.

• Cook-time validation improvements.

  • Pre-load external objects prior to running validators. This is controlled by the CVar 'DataValidation.LoadExternalObjectsForCookValidation' and is enabled by default to match the default editor behavior.

  • Added support for reporting the total validation duration per-validator for cook-time validation. This is controlled by the CVar 'DataValidation.ReportCookValidationStats' and is enabled by default.

• TextureFormatOodle is now a built-in Engine Module instead of a Plugin. It is used for texture encoding by default, regardless of config, even in no-Plugin minimal configurations. The only NVTT and ISPC fallback codecs are now deprecated.

• DataTable export struct to string and file as objects.

• Added more level of precision to editor spinboxes.

  • Shift = Deca (+10/-10)

  • Ctrl = Deci (+0.1/-0.1)

  • Shift + Alt = Hecto (+100/-100)

  • Ctrl + Alt = Centi (+0.01/-0.01)

• Added editor project badge context menu with the ability to copy info to clipboard (project name, version, changelist, branch, build configuration, build date, RHI).

  • Added double click to project badge will copy changelist to clipboard (for QA).

• Added Keyboard Shortcut menu entry in Edit menu.

  • Added Keybinds to access Editor, Project, Keyboard preferences directly.

• Extend "Browse to Asset" capability for Editor Utility Widget.

  • Allow tab context menu actions without activating the tab (web browser style).

• Display ticked objects in ActorPalette viewport, when realtime toggle is enabled.

• Data Validation: The Data Validation Commandlet has been refactored to make custom behaviors via a child class implementation easier to do.

• Add GetPreviewPlatformName Blueprint function.

• Improved ortho view grid density logic when in a mode where view background is irrelevant.

• Data Registry: Fixed "Find Row References" to view references with type FDataRegistryId::StaticStruct() using the name from FDataRegistryId.ToString().

• Add support for filtering shown categories when creating a details view. Add support for hiding headers when creating a details view.

• Added Filter by Selection capability in Content Browser and AssetPicker with keybind ALT+F, it uses the active selection in the context to set filters.

• Added the ability to display specific RGBA color channels in the active editor viewports, as well as options to control how the alpha channel specifically is displayed. These options show up under the View Mode dropdown of the viewport toolbar.

• Added support for -RpcClientNum to handle multiple clients with unique ports, and they just increment after the "client" port in the.ini, when using -RpcConfig=foo.

  • Added support for multiple listening ports for Rpcs.

• Improved BP Editor's menu filtering with additional context options for show flags and view modes and camera settings.

  • Fixed cannot set camera clipping settings in the BP Editor's viewport.

  • Fixed cannot set other show flags in the BP Editor's viewport.

• Allow Abstract classes Tagged Asset Browser Filter Allow Tagged Asset Browser searching for NativeParentClass Allow Tagged Asset Browser searching for Skeleton.

Bug Fix:

• Property Editor

  • Fix struct array elements sharing expansion state after ForceRefresh.

  • Fix struct UPROPERTY rows losing expansion state across ForceRefresh.

• PCG

  • Fix UPCGPointArrayData::GetTransformCopy not respecting inheritance.

    • Revert collapse to use GetTransformCopy again now that it is fixed.

  • PIE: Load as preview fix for managed components.

• glTF Exporter

  • Supporting better primitive number calculations, supporting exports for meshes with unused Materials.

  • Out of bounds crash 'fix' for SourceModel export.

• Fix BroadcastBeginObjectMovement/BroadcastEndObjectMovement pairing on click-only gizmo interaction. GEditor→BroadcastBeginObjectMovement was fired unconditionally in GizmoManipulationStarted, but the matching BroadcastEndObjectMovement was gated behind an early-return that only fires for actual drags. Clicking a gizmo handle without dragging left any listener of OnBeginObjectMovement/OnEndObjectMovement with a permanently-stuck is-moving state until the editor restarted. This was breaking root motion being applied to actors in the anim mixer, causing them to stop responding to root motion until another drag of the gizmo is attempted.

• Scene Viewport: Fix issue when transitioning from the software cursor to the hardware cursor where clamping the cursor position: 1) incorrectly applied pixel scale resulting in incorrect positions; and 2) subsequent mouse movement updates caused a disconnect between the normal and unbounded cursor position.

• Fixed ability to copy a property without any reference = "None" to clipboard to be able to paste it later in a details view row.

  • Fixed show flash animation on copy/paste when using context menu with custom actions.

• Fixed blank project that fail to Quick Launch on Android devices with a Binary build.

• ITF: Fixed some editor input freezing during static mesh async builds. In detail: Moved InteractiveToolsContext invalidation propagation out of throttle-gated Tick into a separate hook called before the viewport tick gate, so input-driven invalidations reach bNeedsRedraw during async asset compilation.

• Fixed an issue that would wipe out instanced struct data when using JSON import and export of Data Tables.

• Change world leak check in the editor to ensure instead of crashing, this fixes issues when transferring maps in Play in Editor with certain editor windows open.

• Fix crash in Editor texture viewer due to preview platforms texture encodings when some platforms were not fully installed on the client system.

• ResavePackagesCommandlet now loads default editor modules, which gives them a chance to bind to UPackage::OnTransferMetadataRequested. If the callbacks aren't bound, data stored in FMetaData is thrown out upon resave.

• User Asset Tags: Fixed ResavePackagesCommandlet discarding User Asset Tags on resave due to UserAssetTagsEditor module not being loaded (metadata transfer wasn't bound).

• Fixed crash saving levels with high actor counts.

• Fixed content browser deleting folders with multiple assets contained in the same package would fail since there is a mismatch between assets count and loaded objects.

• Fixed Launcher process and thread leaks, and memory corruption.

• Fixed color picker would close and not transact any property change on any Blueprint classes, this is caused by the Blueprint rerun construction script and objects replacement happening in editor, the actor and its sub-objects are duplicated and replaced after a property change (value set), this would trigger a details panel refresh with the new objects and underlying property handle would change, old ones would be invalidated, and color picker would close immediately without processing transaction. This would not happen with C++ actor class since they are not getting replaced.

• Fixed Editor Preferences: General Appearance application scale not updated after an import.

• Fixed recursive call to FTargetPlatformManagerModule::ModulesChangesCallback during post Turnkey installation that causes a dead lock.

• Fixed external environment variable changes during turnkey.

• Skipped hit proxy invalidation when the user is controlling a viewport piloted camera, to minimize flush performance cost.

• Fixed pressing a keybind like DELETE in content browser when nothing is selected would still trigger the command for the outliner selection even if it does not have the focus.

  • Added option in editor preferences to hide/show quick jump text (red/blue text) in the bottom right of the content browser (hidden by default).

• Fixed tab location not saved and preserved for assets using workspace editor.

• Fixed General Appearance - Editor Preference : Import values are not saved.

• Modes - Gizmos: Update default mode manager implementation to use the asset editor default mode, and the level editor one uses the level editor default ed mode.

  • Removed swapping of modes - this wasn't having an effect on gizmo visibility in asset editors.

  • This fixes an issue where when legacy gizmos are toggled on globally, a selection must be active in the level editor for the gizmos to display in an asset editor that was using the default editor modes.

• Fix Preview crash caused by copying over Flags when Platforms Cvar copy.

• Give the RenderDoc, PixWin, and Xcode "CaptureFrame" toolbar entries each their own unique id.

• Fixed restore open asset tab location on restart (docked or undocked) after a crash.

• Fix Preview Platform in Editor could fail to show the textures with updated LOD settings for the chosen platform.

• Fix VT thumbnails could appear too bright due to SRGB flag mismatch.

• Fixed an issue where the Recently Executed Python Files menu included files that were run during editor startup.

• Fixed configuration import by removing irrelevant sections for keybinds to avoid same section+key clash on merge.

  • Fixed configuration export by allowing duplicated keys in a section when merging files, this was causing keybinds to be lost.

  • Added notification hyperlink to navigate to exported file.

• Selection: Fix a couple of crashes with ISM selection, and improve the traversal of actor, component, ISM with double clicks.

• Fixed crash caused by the NotifyToolsOfObjectReplacement event being triggered on garbage collected assets.

• Fixed ensure in CurveTableEditor when deleting a curve row.

• Fixed memory leak in content browser when removing collection.

• Fixed logging being delayed by 2 logs calling UAT with the Launcher.

• Fixed possible crash when trying to open a new map.

• Data Validation: Fixed an issue where the data validation fixers wouldn't always capture all the modified packages during the validation.

• Fixed Scene Outliner base selection is lost when ctrl is held and a new search is made to select additional elements in the scene outliner.

• Fix content browser favorites being lost when unmounting plugins.

• Geometry Mode: Fixed erroneous usage of StaticClass in ShutdownModule.

• Asset Rename Manager: Avoid reporting references from sub-objects of redirected path.

• Fixed hotkeys do not work in the Outliner when undocked.

• Fix crash when opening color picker during a hitch.

• No longer moves a viewport-locked actor when input is disabled in that viewport.

  • The "picture-in-picture" preview for camera actors could sometimes rotate that actor as if piloted. This was because the viewport's camera controller was clamping the pitch angle to -90;+90 degrees, so when that came into effect, the output pitch differed from the input pitch.

  • This in turn was picked up by the viewport's camera movement handling as a difference that needed to be reproduced on the locked actor, something that happens when piloting an actor using a movement mode that has inertia for smoother movements.

  • This change just disables that part of the code when input is itself disabled (which is the case in the PiP viewports), since it makes little sense to move a locked actor if the user doesn't have input to pilot it.

• Fix an issue on Mac where the traffic buttons showed up on the rename window.

Deprecated:

• Gizmos

  • Remove experimental gizmo option from level editor viewport. This was rehomed to gizmo settings and profiles.

  • Remove outdated and experimental light gizmo plugin. These are no longer good representations of how we build gizmos in the editor, and have outlived their experimental status. We'll re-evaluate their UX in the future. For now, they needed to be manually activated via the mode manager on the level editor, and required for external teams to make code changes in order to use it. If there was usage of this, it can always be restored from the github history in the meantime.

• Deprecate ChangeFeatureLevel/ChangePlatformLevel(ERHIFeatureLevel::Type) on UGroomBindingAsset and UGroomAsset, and HandlePlatformPreviewChanged/HandleFeatureLevelChanged(ERHIFeatureLevel::Type) on UGroomComponent.

  • Replace the two separate cached feature/platform level members into a single EShaderPlatform CachedResourceShaderPlatform.

  • Replace with ChangeShaderPlatform(EShaderPlatform) and HandlePlatformPreviewChanged(EShaderPlatform).

• Deprecate PIEPreviewDeviceProfileSelector Remove all dependencies to the PIEPreviewDeviceProfileSelector from the Engine.

• Deprecation: Remove deprecated AActor::EditorKeyPressed function.

Datasmith

Bug Fix:

• Fix for crash building morph targets with legacy FBX importer when UseT0AsRefPose is set.

• Fix crash when opening Dataprep Asset.

Framework

New:

• TEDS

  • Cooperative Task Refinement

    • Wait a fixed amount of frames (default: 5) when there is no more time left, if the editor doesn't recover use a minimal processing time (default: 2ms).

    • Added additional stats.

  • Added tab to debug tables to the TEDS Debugger.

  • Refactored Query Capability forwarding to use explicit context environments.

  • Added the ability to put the compatibility layer in immediate mode.

  • Added Query Stack nodes that trigger delegates when a change is detected.

  • Added support for dynamic columns to the new query context.

  • Deprecated `CurrentRowHasColumns` and `CurrentBatchTableHasColumns` in favor of `CurrentTableHasColumns`.

  • Added functionality to retrieve the unique tag that's added to a table.

  • Made the actor table derive from the more general UObject table.

  • Context Capability mocks now have an explicit `Assign_*` function and overloaded functions now work by overloading those `Assign_*` functions.

  • Added additional logging to track the state of TEDS Core and Compatibility (de)initialization.

  • Removed ClearRow in the command buffer for a performance gain.

  • Added a new mapping key type "KeyIssue" to report errors. [TEDS] The type of a mapping key can not be retrieved. [TEDS] "GetAs" was added to the mapping key to be able to retrieve the content.

  • Reintroduced the `TEDS.Enable` CVar.

  • Updated the STedsSearchBbox to support the new query search node.

  • Added 2 new nodes to the Query Stack for searching.

  • Added the ability to calculate a hash of the topology of a table. Changes whenever a row/column is added/removed.

  • Marked more columns to searchable and sortable.

  • Added a utility class to collect row handles concurrently from multiple threads.

  • Cooperative task refinement: Exclude its own runtime from calculating the available time next frame.

  • Allow dynamic columns to be declared at compile time.

  • Added `RegisterHierarchies` to the factories to allow hierarchies to be registered on initialization.

  • Simplified Perforce TEDS data interaction.

    • Skein Perforce TEDS data interaction.

• Replaced cvars by RevisionControlOverlaySettings to support the revision control overlay's options.

• ITF Behaviors: Apply the "input complexity is priority" convention to appropriate base ITF behaviors.

  • Moved the binding complexity priority step definitions to FInputCapturePriority.

  • Mapped and active modifiers automatically count towards a behavior's priority. This can be disabled with the "ITF.UseITFWideBindingComplexityPriority 0" CVar.

• Log a warning if an EditCondition involves a property that is marked deprecated.

• Add ability to indent TokenizedMessage(s) when shown in Message Log(s) to allow for semi-visual grouping.

Bug Fix:

• TEDS

  • Fixed incorrect pre-check before calling `AddCompositionToEntity_GetDelta`.

  • Fixed the result counter in FQueryResult not being atomic.

  • Fixed observers on occasion invalidating the list of pending UObjects in TEDS Compatibility. [TEDS] Fixed an off-by-one bug that could loose async loaded actors.

  • Fixed commands getting stuck in the command buffer.

  • Fixed RemoveColumns called from a query callback not being called on rows outside the active query context.

  • Fixed bug in BatchAddRemoveColumns where an assert could trigger if columns were added and removed in the same call.

  • Mapping performance significantly improved at large scale (100k+).

  • Explicitly flushing the command buffer internally when used in a direct API call to provide consistent behavior.

  • Fixed FNames sorted by the appended number instead of the internal ID.

• Moved SccStatusUpdateTags queries out of PerforceSourceControlProvider to RevisionControlProcessors. This ensures proper tag cleanup even when perforce is not used/connected.

• Fixed resave commandlet failing to find any asset when using the asset registry when the package has a path relative to the engine dir.

  • Added -ForceMaterialAutoUsageFlag command line option, to be used in conjunction with -onlymaterials, to force set the corresponding option on all processed materials.

Interchange

New:

• USD Interchange

  • USD Interchange imports will now respect the UseWorldSpaceNormals material parameter that is produced by landscape exports to USD.

  • USD Interchange error handling will now also collect, deduplicate and display USD SDK errors as Interchange errors.

  • Added support for importing Chaos ClothAssets via USD Interchange via dedicated schemas.

  • Added support for skeletal mesh collapsing on USD Interchange imports. It is now possible to individually collapse Mesh prim hierarchies inside SkelRoots as separate SkeletalMeshes, by using the prim kinds and/or collapsing schemas, controlling the USD Translator's collapsing settings, and the Generic Assets Pipeline options for combining skeletal meshes.

  • Removed the extra sprite added to every spawned scene component on USD Interchange level imports.

  • The option to bCombineStaticMeshes for USD Interchange asset imports has been hidden, as it could conflict with the new collapsing support.

  • Allow specifying custom render contexts for USD Interchange Schema Handlers intended for parsing material schemas.

  • Added support for spawning lights with Nits units on Interchange imports. Imports via USD Interchange will prefer the new Nits units when possible for direct correspondence with USD.

  • Added support for point and spot light source radius when importing via USD Interchange.

  • The USD Interchange import option for filtering imported geometry purposes has moved back to the USD Translator settings (it temporarily became a USD Pipeline option).

  • Interchange USD now supports prim collapsing, both via prim kinds and the dedicated collapsing schemas. The collapsing settings can be configured on the USD Translator settings (the three dots on the top right of the USD Interchange import options dialog).

  • Improved support for camera parameters when importing via USD Interchange, expanding support for clip planes, exposure method, exposure compensation value, and exposure FStop, ISO and shutter speed attributes.

  • Actors, components and assets imported via USD Interchange will only have their properties set to any value if the corresponding source USD attribute had an actually authored opinion. In other words, fallback USD values will no longer be converted into Unreal property values.

  • Refactored the USD Translator to use Schema Handlers: These are classes meant to each describe the translation of a particular USD schema. Users can implement, override, disable, enable and reorder schema handlers from project-level code and plugins, and e.g. implement translation of their custom USD schemas for USD Interchange.

  • Added support for directional light source angle when importing USD stages via USD Interchange.

  • The top-level actor spawned by USD Interchange level imports will no longer display the file extension of the imported layer as part of its display label.

• Added a GenericPayloadData class and an implementation of it on the USD Translator. This allows user code to describe brand new payload data, and to have schema handlers provide that data to user-provided Interchange factories.

• Imports and exports from/to USD may now cause point and spot light source radius values to be clamped to a minimum value, to ensure that the intensity values don't explode to infinity when converting to and from Nits to other light intensity units.

• Importing USD stages with light prims that contain "exposure" animations may now cause the intensity animation track to be baked frame by frame, as the intensity formula contains an exponential function that cannot be correctly interpolated with purely linear keyframes.

• Added a fallback for parsing light attributes from USD prims without the "inputs:" prefix, allowing for backwards compatibility with older scenes.

• Added support for exporting the Refraction channel when baking materials to USD. 1.0 will be used as the default for refraction when exporting translucent materials, to match the Unreal refraction value default.

• Fix missing assets and components on USD imports when the USD prim names differ only by letter casing (e.g. "/Cube" and "/CUBE" on the same stage).

• Added some feedback when the USD reimport fails due to the stage not having a valid prim at the same original prim path.

• Spawn all camera actors as movable when opening or importing USD stages.

• Fixed default refraction and displacement values on the USD preview surface reference materials to match the USD defaults of 1.5 and 0.0, respectively.

• Fixed how the USD Stage transform would not be baked into the OpenVDB texture when importing volume textures into SVT assets via USD imports.

• Interchange will now spawn all light actors with stationary mobility, following the behavior of the Place Actors window.

• Added support for exporting mesh component Overlay Materials to USD as referenced copies of the original mesh prims, but with different material assignments.

• Added support for Capsule_1 and Cylinder_1 primitive schemas when opening or importing USD Stages.

• The DomeLight_1 schema is now supported as the DomeLight schema when opening and importing USD Stages. When exporting to USD, SkyLights will be converted to the new DomeLight_1 schema.

• The USD Importer will now check that the provided reference materials configured on the USD project settings have the expected properties (e.g. the provided two-sided reference material must actually be two-sided).

• On the USD Stage Editor, it should now be possible to author references and payloads on prims that don't yet have a spec on the current USD edit target.

• Prevent the collapsing of prims with alternate draw modes when opening or importing USD stages.

• The Interchange inspector dialog now sorts nodes by name and type.

• Show an error toast when the Interchange import or reimport failed to produce any actor or asset.

• Clamp the subdivision level to a minimum and maximum on the Interchange USD import options dialog.

Bug Fix:

• Reset existing LODModels for reimport, so that Bone bindings and mappings are updated correctly. Also attempting to update SkeletalMeshEditor in case the re-import was triggered outside of the SkeletalMeshEditor.

• Fix a crash when importing some scenes via Interchange if some of the scene's assets fail to import and are canceled mid-import (such as textures failing to parse).

• glTF: Vulnerability fixes for glTF Reader.

• Fixed internal USD errors being uncaught and propagating to Unreal when triggering Async USD Interchange imports in some edge case scenarios.

• Fixed a crash when importing (via USD Interchange) stages with blend shape animation curves that happened to produce no valid curve data.

• Fix level sequence export to USD missing animated attributes of SpotLight components.

• Fixed how USD Interchange imports would produce duplicates of the same textures if the textures were used on different material inputs.

• Fix how the Interchange texture factory would delete existing texture assets when reimporting in some scenarios.

• Fixed how exporting levels to USD would not work with the traditional AssetExportTask Python snippet.

• Fix old assets still being referenced by the level and other assets after reimporting USD Stages in some scenarios.

• Fix texture assets imported via USD Interchange having names containing the source texture file extension.

• Fix static mesh actors imported for collision meshes via Interchange sometimes ending up with the render mesh assigned.

• Fix memory stomp on the stack in TiffImageWrapper. TIFFGetField expects a pointer to uint32 when using TIFFTAG_ROWSPERSTRIP but was passed a pointer to a uint16.

• Fixed Interchange showing the "There were issues with the import" toast when the recorded issues were due to previous imports.

• Fixed a crash when importing USD stages via Interchange and failing to find an existing material asset referenced by the stage via an Unreal Material prim.

• Fixed the handling of nested geometry purpose opinions when opening or importing USD Stages.

• Fix prim copy-paste behavior when selecting multiple prims at once on the USD Stage Editor.

• Prevent valid UTF8 characters from being unnecessarily sanitized away to underscores in some operations on the USD Stage Editor.

• Prevent loss of transform opinions in some edge cases when writing out attribute values to USD with a stage opened on the Stage Actor.

• Fix logic issue on the Interchange Inspector UI preventing the selection checkboxes from affecting the top-level nodes.

• Fix crashing when importing Geometry Cache assets from USD in some edge cases.

Scripting

New:

• Added a FindReferencesByTag function to the Gameplay Tags Toolset.

• Added a bOverwriteExisting option to CreateAsset, useful when automating/script object creation to not prompt.

• Added EBatchCreateFontAsset::CreateIfNoFontExists to help with automated importing not creating Foo_Font1, Foo_Font2 unncessarily.

• Exposed on option on UFontFileImportFactory to create a matching UFont for the UFontFace when programmatically/scripting importing a font.

• Added exposure to Level Editor Subsystem to Get and Set a level editor viewport camera's location, rotation and FOV Clamps FOV between 5 and 170 degrees, in line with the Editor UI spinner box UI.

• Require that SupportedClasses be filled out on UAssetActionUtility and UActorActionUtility Actions with no SupportedClasses filled out will now cause a data validation error.

• Added Optional property support to Python.

  • Python can now read and write Optional properties from UObjects and UStructs, where None is treated as unset.

    • Note: This does mean that you can't distinguish between an unset Optional and an Optional set to a null UObject, but the latter is an unusual use of Optional.

  • Python generated types can create Optional properties via a tuple of two values, where one is None and the other is the value type of the Optional (in either order),

    • E.g.:  ``` @unreal.uclass() class TestOptional(unreal.Object): prop = unreal.uproperty((str, None)) @unreal.ufunction(params=[(None, int)]) def func(self, opt): pass ```

• Exposed utils to import/export a string table from CSV to BP/Python.

• Scriptable Tools: Added MakeTransactional BP function to ScriptableInteractiveToolPropertySet so that tools can optionally enable transactions on a property set.

Bug Fix:

• Scriptable Tools:

  • Fixed ScriptableToolsFramework dependency on non-redistributable ToolWidgets module.

  • Refactored SDraggableBoxOverlay usage to isolate ToolWidgets as a dependency to ScriptableToolsEditorMode rather than ScriptableToolsFramework.

  • The coupling of ScriptableToolsFramework on ToolWidgets prevented runtimes from shipping the framework due to ToolWidgets non-redistributable status as part of the Source/Developer modules.

• Python-defined function return value fixes.

  • Fixed the order that packed return values are built, so they match the order that the types are defined (and match C++).

  • This was a bug previously fixed for the input arguments, but not the output arguments.

• Fixed crashes that could occur when reinstancing classes generated via Python.

• Fixed FPyWrapperSet::Intersection/IntersectionUpdate failing for builds where TSet was TCompactSet The updated implementation (iterating in reverse) works correctly for both TSparseSet and TCompactSet.

• Generate the TraceType/ObjectType ScriptName from the CollisionChannel DisplayName, if the CollisionChannel ScriptName is empty The old broken names are still available as deprecated aliases.

• Ensure the PythonScript commandlet enables source control prior to running the script Source control cannot be directly enabled in Python, so it's simpler to enable it from C++ before running the script.

UI

New:

• Tool Widgets

  • Deprecate SDraggableBoxOverlay.IsDraggable for Draggable to conform with established naming conventions. Deprecate SDraggableBoxOverlay.RestoreFromDragBoxPosition for SetDragBoxPosition to conform with established naming conventions.

  • Added resizing support to SDraggableBoxOverlay.

  • Make DragBoxPosition properties visible to details panel.

  • Added DragOverridesCenterAlignment to SDraggableBoxOverlay to allow dragging to override center alignment on either axis. This is useful for when we want a DraggableBoxOverlay to start centered but still allow users to customize its position.

• New experimental Semantic Search plugin: Changes content browser search to use a vector index-based search instead of the default keyword search.

• Teds Table Viewer Column: Support column metadata to disable sorting for a specific column.

• Added Gurmukhi to require full shaping.

• Hierarchy Editor: Multi-selection generalization for drag-drop and details panel.

  • Activated

  • Added option to turn off multi-selection via view model.

  • Disabled for Niagara (details customizations don't play nice).

  • Enabled for property bags (caveat: Only works well for same-type selections).

  • Drag initiates from tree view selection, not just the row under cursor.

  • All-or-nothing: If any element can't be dragged, entire drag refused with toast.

  • Hierarchy-aware: Parent+child selections skip child during drop (comes with parent).

  • Drop order always matches tree display order regardless of selection order.

  • Drag decorator shows "(+N)" for multi-element drags.

  • Drop validation checks all elements against target; all must pass.

  • SetObjects() for multi-object editing when multiple elements selected.

  • Name area shows "(+N)" badge; tooltip lists all selected elements via OnGenerateCustomDetailsPanelNameWidget.

  • New SupportsMultiEditInDetailsPanel() virtual to opt out.

  • F Dragged Element Entry: Element wrapper with bIsContainedInAnotherDraggedElement flag.

  • F Data Hierarchy Drag Drop Context: Wraps entry array with GetTopLevelEntries/GetPrimaryElement.

  • FHierarchyDragDropOp takes FDataHierarchyDragDropContext; CreateDragDropOp signature updated.

  • CreateDragDropOp overrides updated for new signature.

  • Custom drag decorators render all elements vertically for multi-drag.

  • Multi-edit disabled via SupportsMultiEditInDetailsPanel.

  • FInstancedStructDataWithHeaderDetails uses EnumerateConstRawData instead of GetValueData.

  • Fixes missing category headers (e.g. "Numeric") during multi-object editing.

• Added a Crash Diagnostics panel to the Editor Diagnostics window to view recent editor crashes.

• Add button to enable/disable editor shortcuts when PIE is active.

• Added Dynamic Invalidation to the Material Editor Graph.

• Added Data Hierarchy Editor support to FInstancedPropertyBag:

  • PropertyBagSchema class can now direct the property bag details to an optional HierarchyRoot object.

  • PropertyBagSchema class also contains information about hierarchy types.

    • This can be used to subclass and add properties.

  • Moved some util functions around hash calculation into public

  • Replaced some UEdGraphSchema with UPropertyBagSchema.

  • Added more encapsulation so that FPropertyBagInstanceDataDetails is more standalone and can be subclassed.

  • Removed some of the construct params in favor of FPropertyBagInstanceDataDetails looking relevant data up via property handle.

  • Added InstanceMetaData support to allow forwarding metadata to an inner FInstancedPropertyBag.

• S Subobject Editor::FindSlateNodeForHandle: find slate node for FSubobjectData that doesn't have a WeakObjectPtr but does have a corresponding teds row.

• Project Launcher fixes for recent changes in Cooker behavior:

  • Zen Streaming content scheme is only used for new profiles when bUseZenStore and AllowRemoteNetworkService are set.

  • Add profile validation error when trying to use Zen Streaming to a remote device when AllowRemoteNetworkService is false.

  • Platforms menu Quick Launch disables unversioned cook when using LegacyIterative.

• Added Dynamic Invalidation to the Place Actor Panel.

• Added Dynamic Invalidation to the Content Browser.

• Added Dynamic Invalidation to the Scene Outliner.

• Added support for drag-and-dropping a texture onto an existing texture sample node to replace the texture.

Bug Fix:

• UMG/Slate

  • Fixed SListView ScrollIntoView alignment math (local-space deltas and CenterAligned culled-target offset) so centered and partially clipped items scroll correctly at non-default DPI.

  • Fixed proximate intra-entry navigation to reject focus targets outside the list bounds when bEnableProximateEntryNavigation is enabled.

• Fixed crash in PropertyPathHelpers::SetPropertyValueFromString when propagating properties to widget archetype instances.

• S Draggable Box: Fix for single right-click entering drag mode.

• Fixed selection outline of Nanite-enabled mesh components when selecting individual components below an actor. Previously, deselected components on the same actor would not render with the muted outline color.

• Fixed the editor selection outline of Nanite-enabled Skeletal Mesh and Instanced Skinned Mesh components.

• Fixed overlay colors not working with non-Nanite Instanced Static Meshes.

• Fixed nullptr dereference when generating tooltip in widget reflector for native widget class types.

• Tool Widgets: Fixed SDraggableBoxOverlay accumulating Padding when invoking SetBoxAlignmentOffset with center alignment.

• Fixed crash when dismissing notifications after hot-reload.

• Fixed right click crash on tagged asset browser sections.

• Fixed incorrect transform handling of static meshes in the viewport.

• Optimize select actors in statistics tab.

• Fixed edit change conditions not correctly gathering the edited UObject if it's an instanced struct that was added to the UI, as a complex parent was found on the way up that was not the owning object node.

• Fixed missing objects in property change event for edit condition toggling.

• Fix an issue where Status Bar tool tips appeared in another screen (or overlapped the status bar if there was no monitor to the right).

• Added IsAssetVisible check for tagged asset browser extension functionality.

UX

New:

• Added new input settings tab containing keyboard shortcuts and future shortcuts.

  • Added sidebar to settings editor that shows left panel when more than one item (docked) and hides when it contains a single item.

  • Import/export (All) will only handle shortcuts instead of all editor settings now.

  • Updated autocompletion and suggestions to use new container.

• Improved Settings Editor UI to match the rest of the editor (tree view, splitter, category, style).

  • Improved search to only apply to the selected section instead of showing all results.

  • Improved Filters and suggestions to be dynamic and (dis)allow specific sections (they only appear in the proper context).

  • Added keybind action button to search for specific keys pressed.

  • Allow partial search match from begin or end.

  • Added icons for keybind and cvar filters.

• Added advanced preview scene options to customize floor, floor rotation, floor scale and floor material.

  • Added advanced preview scene option to clone a profile from existing ones.

  • Added advanced preview scene keyboard shortcuts to navigate to next/previous profile (SHIFT+ALT+Up/Down).

  • Reworked the preview scene settings tab UI.

  • Property AssetPicker can now be customized with additional metadata to set ViewType, ThumbnailSize, ThumbnailScale, SettingsName.

  • Deprecated "show grid" property since it's not relevant to all context.

  • Fixed preview scene not loaded properly on editor startup.

• Property Editor: Add an option to add a color bar on every row in the category.

• Persist import interpolation mode for reimporting CSV as curve table.

• Interactive Tools Framework: Modified UInteractiveToolPropertySet::SaveRestoreProperties to only instantiate a property cache entry when saving. This permits successive calls to RestoreProperties to behave as expected, particularly in the case where a tool inherits from a base tool class, but wants to modify the defaults of an inherited property set. In that scenario, both the base class and derived class would issue RestoreProperties on the inherited property set.

  • Prior to this change, the first call to RestoreProperties would instantiate the property cache and detect that the property cache was just created to avoid the restore. The second call to RestoreProperties would incorrectly see the just created property cache as evidence that there is saved data to restore and copy the default CDO data to the tool.

  • By only instantiating the property cache on save operations, the behavior is more consistent and avoids tools having to create awkward workarounds using separate property cache IDs to workaround the issue.

• Fixed combo box widget tooltips appear on dropdown list items across the editor making it hard to navigate across options.

  • Added a way to extend force repel zone on any widget with a slate attribute.

• Added scale option in config for warning/error messages in texture editor viewports.

• SSegmentedProgressBar is now available for displaying the progress of a multi-state workflow.

• Replaced delete content browser popups by dialogs to attract user attention (folders, favorites, collections).

  • Improved delete dialog widget to include pending deletion folders.

  • If the folder is not empty and contains assets, a first dialog will be shown to avoid loading all assets recursively on a mis-click otherwise only the main delete dialog widget will be used.

• Re-enabled delayed change notification on SceneOutliner search.

• Added asset class icon with color to the save all dialog content table row.

• Updated content browser suggestion filtering so only paths starting with the currently typed text are shown.

• Open editor, project, input settings in "All settings" by default instead of "Appearances" and "General" since search is now localized.

  • Auto focus search box when opening settings.

• Added drag and drop support from content browser to material editor viewport to change preview mesh.

  • Dropped preview mesh will become default preview mesh when reopening asset editor.

• Added Material Instance to custom filter in content browser to search for these asset type.

• Add recursive expansion/collapse on TreeViews when navigating with the arrow keys to match the shift-click expansion arrow behavior.

• PCG Property Bag: Hierarchy Editor Support added.

• The editor layout now properly restore the position and scale of the level editor window position and the other windows managed by the tab manager.

• If CTRL is pressed and folder are dragged then copy/move folders is performed on drop.

  • If CTRL is not pressed and folders are dragged then add/reordering favorites is performed on drop.

  • If favorites folders are dragged then reordering is performed on drop.

  • If file assets are dragged then copy/move items is performed on drop.

• Fixed ToolTip Override that was not working for FPropertyHandleBase::CreatePropertyNameWidget.

• Show Favorites/Modified sections in details panel filter bar, use details settings and check "Show Helper Sections"

  • Add/Remove category items from favorites using context menu on a category.

  • Expand/Collapse details panel root categories using shortcuts : CTRL+SHIFT+X and CTRL+SHIFT+C, menu entries and commands actions are now using the same code path.

  • Fixed SHIFT+Click on expansion arrow do not recursively expand advanced category.

  • Grouping properties based on their original category in favorites and removing Advanced.

• Enabled search in data table row editor.

• Allow reordering of favorites list (above or after).

  • Disallow move or copy operations of folders in the favorite list.

  • Added edit favorite dialog to set an alias and shortcut to a favorite item (through context menu).

• Content Browser - Column View : Added description of how many columns are displayed and from what asset type they are from. Without that information, it's hard for a user to understand there are some missing columns simply because they're not part of the columns of the asset type for which there's the most assets on display.

• Added context menu entry in editor preference and project settings to copy associated CVar to the clipboard if any.

  • Added row extension button to quickly spot properties with a CVar and copy them to clipboard.

• Improved "Keyboard Shortcuts" editable input UI to follow unreal theming.

• Fixed ContentBrowserModule's "AssetClassesRequiringDynamicTags" feature. It now stores classes as FTopLevelAssetPath in order to properly detect them. Also, now, child classes of an asset class requiring dynamic tags are also considered requiring dynamic tags.

• Added an option to sort the content browser filters in alphabetical order or insertion order.

  • Refactored loading filter code to restore filter in the correct order instead of the random type registration order.

  • Reordered all context menus in the content browser to be alphabetically sorted (Other filters, Custom filters, Common filters).

• Added Open Screenshot Folder button to High Resolution Screenshot tool.

• Added browse to asset when right clicking the tab of an editor asset tab, action is only enabled for assets (non transient).

  • Added browse to level when right clicking the tab of an editor level tab, action is only enabled for saved level.

• Use the class display name when showing the asset type in the generic asset viewer (as we do in the Blueprint editor).

  • The tooltip now for the "go to source" hyperlink shows the native class name for both the Blueprint editor and asset viewer.

Bug Fix:

• Fixed sidebar widget stays in an intermediate state when clicking multiple times on the sidebar button.

• Asset thumbnail: Fixed color that was not updated to match the asset type color in some cases.

• Fixed Blueprint Editor Drag and Drop of asset in tree hierarchy does not match user intent.

• Fix an editor crash that could occur for reset to default on class reference values in the details view.

• Fixed non-displayable references list is not interactable when deleting pending assets in dialog.

• Fixed set and map property editors that would not show "Multiple Values" when editing multiple objects with a different number of items (they both behave like the array property editor now).

• Fixed asset search box suggestion width should match search box width instead of changing based on in view content.

  • Fixed content browser search suggestions should appear above to avoid obfuscating filtered results.

• Content Browser: Fixed an issue where the previous opened path would not always be restored properly when rebooting the editor.

• Add missing support for instanced struct value edit propagation and some fixes for its reset to default UX.

• Fix for stomping an annotation that has already been set during edit change propagation.

  • (Example) This was (incorrectly) marking child BP assets as needing to be saved if they happened to be open for edit alongside their parent in the BP editor, in cases where they would (correctly) not be dirtied if not also open for edit.

• Fixed the AI assistant tab label centering in the Panel Drawer.

Foundation

New:

• Optimized FSplineMeshSceneProxyDesc::CalculateShaderParams to skip calculating the MeshDeformScaleMinMax if the mesh isn't nanite enabled. MeshDeformScaleMinMax is only used for nanite LOD calculations and computing it is very expensive.

Bug Fix:

• Based on, fixed two issues in primitive drawing utilities:

  • DrawFlatArrow now correctly applies the thickness parameter, which was previously unused.

  • F Batched Elements::AddReserveLines no longer reserves twice the required number of line entries, reducing unnecessary memory allocation.

• Fix FCompression initialization could occur on first use on a thread, causing a crash.

• Quote path of PerfreportTool.dll when calling it from AutomatedPerfTestNode.

Build

New:

• Update Intel OneAPI supported version to 2026.0.0.

• Add UE_PLATFORM_* definitions to mirror existing PLATFORM_* definitions.

• SN-DBS now uses per-platform tool template directories to avoid rare cases of ambiguity when compiling for several platforms at once.

  • Requires SN-DBS 2.6.10.1020 or later to utilize the new code path. Support for older versions of SN-DBS remains, but UBT will emit an error if it encounters a situation that requires the upgrade.

• Added -SkipEncryption support for IoStore containers.

• Remove 2GB limitation when generating psym files by never storing the output as a string.

• UhtSpecifierValueType.Legacy is now obsolete. UhtSpecifierValueType.None should be used in its place.

• Added packaging option to allow specifying alphabetical-cluster-sort and alphabetical fallback ordering for a specific prefix match of container names.

• Added support for patterns such as "FString()" for default values in UFUNCTIONs.

• Build Graph: Added option ErrorIfNotFound to RetrieveArtifactTask to control if an error is thrown when an artifact cannot be found.

Bug Fix:

• Add support for UStructs in namespaces for TInstancedStruct properties.

• Set DefaultBuildSettings for the BlankProgram template. This prevents compilation errors when the template is used outside the engine folder.

• Add support for UStructs in namespaces within RigUnit.

• Fixing an issue where types wrapped in WITH_EDITORONLY_DATA would not have that definition reflected in the generated code.

• SNDBS: Prevent exception when there is no explicit_input_files key.

• `class IFoo {... }; UCLASS() class UFoo : UObject {... };` no longer results in an error claiming that IFoo is missing GENERATED_BODY().

• Fixing issue where delegates were not properly bound by #if/#endif pairs in their definitions. Added "Editor" as a distinct defined scope separate from EditorOnly.

Compile Time Improvements

New:

• Reduced linking time on clang with LTO by disabling debug info upgrading, sice we build everything with the same toolchain.

Core

New:

• DDC

  • Added record/value to cache put responses to give callers a copy of what ended up stored in the cache.

  • Added ApplySkipPolicy to apply ECachePolicy::Skip to values and records.

  • Added a constructor for FCacheRecord from FCacheKey.

  • Added TryLexFromString for FCacheKey and FCacheBucket.

  • Added support for natively-async cache stores to skip creation of an async wrapper.

  • Added cache store tests.

  • Added custom cache graph support with, e.g., -DDC=(EnginePak,Cloud), or in the same format with the DDC.Graph CVar. Any configuration that is valid in a graph is supported, such as -DDC=(ZenLocal,Cloud(ReadOnly=true)) to create a graph with ZenLocal and a read-only Cloud.

  • Added BuildLegacyCacheKey to support migration from the legacy API.

  • Removed unused short key and legacy mode functionality.

  • Updated graph creation to use the new config API.

  • Require that RawHash matches when present in GetChunks(). It was a hint and now it is a requirement to avoid callers receiving different data than they anticipate.

  • Added ECachePolicy::NonDeterministic to flag known-non-deterministic data to avoid noise in -DDC-Verify mode.

  • Serialize put requests into replays and replay them as gets.

  • Improved DDC graph selection. Consider every -DDC=... command line argument as a candidate. Removed broken -DDC=None functionality. Fixed DDC.Graph CVar overriding the installed default by making it empty by default. Added -DDC-NoDefaultGraph command line argument to remove the default graph from consideration.

  • Added a linear-probing hash table for internal use by DDC and DerivedDataTool.

  • Added a concurrent chunked sparse array for internal use by DDC and DerivedDataTool.

  • Removed obsolete DDC WaitForQuiescence from AppPreExit.

• Compact Sets: Resolved remaining issues to allow compact sets to be enabled safely:

  • Re-added key storage to ensure full compatibility with GC and object relocation.

  • Fixed natvis and GDB printers for sets and compact sets.

  • Removed unused feature auto relax map.

  • Reworked compact set lookup algorithm to account for some specific edge cases.

  • Improved run-time detection of broken lookup, usually due to external memory changes.

  • Added BuildConfiguration option bUseSparseSetStrictMode that, when enabled, will cause spare sets to be more strict in their usage so compile issues can be fixed to allow switching over to compact sets.

  • Added BuildConfiguration option bUseCompactSetAsDefault that, when enabled, will swap the implementation of TSet and TMap to use compact sets instead of sparse sets. TCompact[Map|Set] and TSparse[Map|Set] still exist for explitic usages, but explicit forms cannot be used as UPROPERTY's.

  • Perf: Enabling compact sets in Fortnite saw 40-90MB of memory savings, depending on platform, as well as overall improved performance in most CPU threads.

• Add TSubScriptStructOf. Similar to TSubClassOf but for UScriptStruct. Add an editor picker that works with NoClear and the metadata.

  • Meta Struct: The struct path of the base struct displayed in the picker.

  • Show Tree View: The picker uses a tree view or a list view to display the available struct.

  • Show Display Names: Uses the DisplayName of the selectable struct.

  • Hide View Options: Hides the options menu in the picker.

• Struct Utils: FInstancedPropertyBag serializes with the default values. With tagged serialization, the full instance will be skipped if the descriptions and the values are the same. If the descriptions are the same, only the values that are modified will be serialized. If the descriptions changed, then the default is not used. When using FInstancedPropertyBag in a BP, it might appear that it works without this changelist. This is due to the reinitialization process during compilation. Without this change list, it might not work depending on the loading order.

• Added "UObject Count" trace counter.

• Introduce indirection for AssetRegistry cache files, so we don't need to overwrite them.

• Introduced UE_JSONOBJECT_LEGACY_STRING_KEYS which defaults to 0, set to 1 to revert FJsonObject to its FString-based interface.

• Replaced the hash for FNameEntryId to avoid extremely poor worst-case distribution.

• Added asset chunks deduplication option in UnrealPak for IoStore containers, accessible via [/Script/UnrealEd.ProjectPackagingSettings] bDeduplicateChunks=true.

• Added C++ Concept for pointer convertibility.

• Added support for non-power-of-two FName pool shard counts, to allow alleviating hash table load without needing to double the capacity.

• `TVariantPtr` no longer requires non-UObject type to be `TSharedFromThis`, accepts `TSharedPtr`.

• Added the concept of auto-loading non-plugin modules based on.ini settings (see Auto Load Modules By Phase: And [AutoLoadModulesByPhase_Editor] in BaseEngine.ini).

  • Making use of it to load TargetPlatformManagerModule earlier to kick off the async UBT process.

• Prevent LexToString(bool) from hijacking types that implicitly cast to bool. This makes missing or unresolvable LexToString overloads fail at compile time instead of being hidden by a bool conversion.

• Added UE::CInsertable as a proper concept and UE::CInsertableInto that reverses the parameters.

• Added FText::AsMemory overload accepting a specific EMemoryUnit.

• Fix json library to use actual object class instead of static class from templated class type.

• GC: Add the option to GC based on pending actors to unload (in addition to existing mechanism that uses number of levels) for finer control (disabled by default). Number of levels can be inaccurate given the discrepancies between level counts and memory impact. across main grid / data layers Add the option to GC based on pending actors to unload (in addition to existing mechanism that uses number of levels) for finer control (disabled by default). Controlled via `s.ContinuouslyIncrementalGCWhileActorsPendingPurge`/ `s.LevelStreamingLowMemoryActorsPendingPurgeCount` and `wp.Runtime.LevelStreamingContinuouslyIncrementalGCWhileActorsPendingPurgeForWP` (for partitioned worlds).

• Added the frame counter (when present) to structured log output.

• Oodle updated to 2.9.16.

• Added natvis visualizers for Compact Binary.

• Added MoveAssignScriptStruct to UScriptStruct for move-semantic support in type-erased struct operations. Introduced the WithMoveAssign trait on TStructOpsTypeTraitsBase2 (following the pattern of WithCopy), the STRUCT_MoveAssignNative flag, the FCapabilities::HasMoveAssign capability, a MoveAssign fake-vtable entry, and ICppStructOps::HasMoveAssign() / MoveAssign(). STRUCT_MoveAssignNative dispatches to C++ operator=(T&&); STRUCT_IsPlainOldData uses memcpy; the fallback calls CopyScriptStruct for zero regression on non-opted types.

• Parking Lot: Use low-level virtual memory API for allocations to allow our allocators to depend on ParkingLot.

• Rename some private stats types to avoid collision with platform SDKs.

• Deprecate and remove the FField virtual functions Bind(), PostLoad() and BeginDestroy() that are implemented but never called.

• Added && TShared/Weak... constructors and StaticCastShared/Weak... helpers. Removed WeakPtr from TSharedFromThis.

• Changed MallocBinned3 max small bin config to 14kb by default as it offers better performance\memory in our testing.

• Added filtering by key to the derived data cache key filter used for simulated misses, verification, and replay.

• Added IsLockedByCurrentThread() to the recursive mutex types.

• Implemented an easy-to-use mechanism for deprecating existing cvars.

• Asset registry cache will now memory-map its tag data storage, reducing RAM footprint by GBs in large projects.

• Made TSharedString transactionally safe by using TTransactionalAtomicRefCount.

• Converted UE_LOG to use log records internally. This adds file, line, and context to every UE_LOG even though they are inherently unstructured.

• Simplify serialization of ClassFlags in UClass::Serialize by updating and always using CLASS_ShouldNeverBeLoaded.

• Reduced the stack cost of a failed ensure from ~32 KiB to ~2 KiB.

• Added packaging of Derived Data Build Workers and updated DerivedDataTool to work with them.

• Made UTF8TEXTVIEW constexpr.

• Added -CookPackageDir= to the cooker to allow cooking a directory, and when combined with -cooksinglepackagenorefs, then only that directory will be cooked.

• Added a DerivedDataBuildController to support compiling shaders through the Derived Data Build API.

• Improved to the Derived Data Build Worker startup time. Fixed directory deletion in the local executor for the Derived Data Build Worker.

• Runtime: Add: WebRTC initialization on Android.

• Optimized variable-length integer encoding in VarInt.h.

• Allow an IInstallBundleSource implementation to override the default PAK mount priority via its FInstallBundleSourceUpdateContentResultInfo.

• Added OnHDRScreenshotCaptured delegate to UGameViewportClient, fired when an HDR screenshot is captured. OnScreenshotCaptured does not fire when HDR is enabled. A separate delegate is needed to allow returning the HDR bitmap as TArray<FLinearColor> rather than TArray<FColor>.

• Removed unnecessary dependencies from LauncherServices, RenderCore, ShaderCompilerCommon, and TargetPlatform Reduces the size of programs like ShaderCompileWorker that do not otherwise depend on some of the removed dependencies.

• Added TargetRules.bEnableConfigSystem to allow disabling loading config.

• Enable range-based for loop support for `TFilterCollection`.

• Commandlets will now print peak used memory at the end of their execution.

• Added option in UnrealPak to keep unchanged assets at the same file offsets in IoStore containers as they were in the previous build, accessible via [/Script/UnrealEd.ProjectPackagingSettings] bUsePatchInPlaceLayout=true.

• No longer performs a normal config save if the PreSaveConfigFileDelegate returns that it saved the file. This can reduce some slow unnecessary disk operations on some platforms. Can revert to original behavior by either setting ini.SkipSaveIfPreSaveSucceeded to 0, or by not incrementing SavedCount from your delegate implementation.

• Add cvar, core.EnsureBreakEnabled (default:True), to disable debugger breaking when ensure statements are hit to allow skipping unrelated ensures while debugging longer processes.

• Added a DerivedDataTool Copy command to copy data between caches.

• TLruCache: Add SetMaxNumElements / Declare default move constructor/assignment and define proper copy/assignment as they are currently broken (with unittest) [PCG] Cache: optimize cache grow and use SetMaxNumElements instead of the previous full copy that was happening.

• Streamable Manager:

  • Added a mechanism to just-in-time trickle async load requests on a streamable handle.

    • Added a mechanism to batch/trickle async load requests on a streamable handle.

      • Opt-in (enabled via UE_ENABLE_STREAMABLE_JIT_ASYNC_LOADING=1) and by setting bUseJustInTimeAsyncLoader=true or if batching is enabled globally (s.StreamableEnableJITAsyncLoadingGlobally).

    • The initial batch size is set as per s.StreamableJITAsyncLoadingInitialBatchingFactor which is a factor of the total number of requests queued for a streamable handle (default is 0.25).

    • This can be used to cancel or queue subsequent async load requests at updated priorities (see FStreamableHandle::SetPriority) which would get picked up when subsequent requests are queued.

    • Opt-in by setting bUseJustInTimeAsyncLoader=true or if batching is enabled globally (s.StreamableEnableJITAsyncLoadingGlobally).

• Optimized FMath::RoundUpToPowerOfTwo[64] for Clang.

• Used MPSC queue instead of MPMC queue for log output.

• Added && to Value and operator* in TOptional.

• Refactored UObject::LoadConfig into some Context objets to break up the wall of code and also be able to more easily add functionality (like passing a preloaded FConfigFile to LoadConfig).

• Added TAutoConsoleVariableDeprecated_NoReplace CVar type that is used to deprecate a cvar without replacing it with another one. The value can still be queried, but it will ensure (or warn or assert depending on setting). Similarly, FAutoConsoleCommandDeprecated_NoReplace was added for deprecating a command without pointing at another.

• Added support for an optional.ini file that is applied after engine/project plugins and before GFPs and Hotfixes. This allows a project to override plugin settings if needed (likely to be rare, but there is a use case for it). It is called PluginOverride.ini (ie PluginOverrideEngine.ini) and is stored in Project/Config. There is no per-platform version.

• Added bool return type to FConfigCacheIni::Flush to know if the information was actually written to disk.

• Added parameters to TGuardConsoleVariable to be able to specify priority when setting cvars from testcode.

• Added FrameNum and UTC time to stat unit so we have a way to match up video captures with logs, etc. Requires setting "stats.UnitTimestamp" cvar to enable.

• Use UTF-8 for structured logging format strings.

• Added the UE_LOGF family of macros for unstructured logging with UTF-8 format strings.

• Added FPlatformString::FormatV and TCString::FormatV to provide GetVarArgs with a usable return value.

• Add EAllowShrinking arg to TIndexedContainerIterator::RemoveCurrent and TIndexedContainerIterator::RemoveCurrentSwap.

• Added concept UE::CContiguousRangeOrRef.

• Moved GetDataHelper to UnrealTemplate.h.

• Assert on re-entrant calls in ParkingLot to catch invalid usage by callers.

• Added WaitFor and WaitUntil to FConditionVariable.

• Added console command to reload a package in the editor, including in -game obj reloadpkg package=/Game/Foo.

• Added the OptStreamGotTo optional param to most of the FParse::Value() functions (it was only on string versions before). Didn't add to FText version because it uses a different parsing code that doesn't return the end of the value.

• Added trait TIsCharEncodingCompatibleWithUTF8CHAR.

• Add error detection for SQLiteSupport.

• Moved log category macros to LogCategory.h.

• Fixed WarnFilterScope for structured logging and added CHECK_LOG_SCOPE for common cases.

• Cleaned up the unused FConfigFileHierarchy::DynamicKey code.

• Allow plugins to have PluginName.ini along with Base/DefaultPluginName.ini (but deprecated).

  • Also deprecated BasePluginName.ini so we can eventually look for fewer ini files during plugin mounting.

  • Show a message with GFP old style names as well.

• Removed unnecessary confighierarchy entries, and plugin config branches that have no static layers.

  • Removed the "config xxxx" console commands in SHIPPING.

• For GameFeaturePlugins, renamed Conole Variables: And [ConsoleVariables_HighPriority] to [PluginCVars_LowPriority] and [PluginCVars_HighPriority]

  • Added initial support for them in Preview, although it only works if in Engine.ini files, a future change will work to address this.

  • GFP Hotfixes still use Console Variables: Because they set at Hotfix priority, not Plugin.

Bug Fix:

• DDC

  • Allow records with no values in the Memory cache store. DDC: Report an error when the memory cache store exceeds its size limit. DDC: Verify that content exists in the FileSystem cache for differing values even if they are expected to be non-deterministic.

  • Fixed Zen client support for out-of-bounds chunk reads.

  • Fixed out-of-bounds chunk reads in the memory cache store.

  • Validate RawHash in compressed buffer headers to mitigate invalid data being returned by Zen.

  • Fixed a dangling string view in TryFindCacheGraphConfig.

  • Fixed a file system cache store race with initialization of FRandomStream relative to starting the maintenance thread.

  • Fixed a crash in FTimeAveragedStat and added tests.

  • Fixed use of ',' as a delimiter in unquoted arguments for simulated miss types and keys in DDC.

  • Fixed a DDC crash when recovering from a failure to create a non-default graph containing a pak store.

  • Fixed Cloud DDC reauthentication during shutdown by ensuring that DesktopPlatform unloads after DDC.

• Add a CVar named "Serialization.EnforceLinkerObjectBounds" (default true) to bounds check object data reads from.uasset in editor - this makes loading data after changing a variable type safer.

• F Instanced Struct Container: Fix missing default initialization of items prior to serialization on load causing invalid values if delta serialized.

• In FMonitoredProcess::TickInternal(), set bIsRunning = false _before_ calling OnCompleted(), so a Completed delegate can call GetFullOutputWithoutDelegate() without asserting. (Same change to OnCanceled())

• Fixed a dangling pointer in FConfigContext when using TemporaryBranch.

• Fix FName::CompareSensitive not always comparing case-sensitively.

• Allow newly created packages with a file on disk to be reloaded.

• Updated "stat fps" frame time indicator to use the same smoothing factor as "stat unit".

• Windows Platform File: Fix IterateDirectory to honor the contract to return false if the input directory does not exist. Keep the behavior that it returns true for directories that exist but are hidden or otherwise uniterateable.

• Updated FObjectPropertyBase::ParseObjectPropertyValue and FSoftObjectPath::ImportTextItem to handle parsing object paths with spaces in them.

• GameFeaturePlugins can now work from locations listed in AdditionalPluginDirectories (in a.uproject).

• Do not reset external package when renaming actor changing outer in PIE packages, fixing the asymmetry.

• Core/HAL: Fix: FSharedEventRef not respecting EEventMode passed in to the constructor.

• DiagnosticCheckNaN functions in various math library types no longer change the object being tested to a non-0 default value. This will increase the number of log messages but the old behavior involves mutation in a const member function and was a potential data race.

• Adjust CheckObjectValidBasedOnItsFlags to be consistent with other validity check such as TWeakObjectPtr::Get.

• Ignored SetColor verbosity in FOutputDeviceDebug.

• Fix for CrashReportClient reading project settings when bAllowNonUFSIniWhenCooked is set.

• Log an error if the class import doesn't have an outer (i.e reported as a package) when calling GetExportClassPackage.

• Fix multiple bugs where object flags and properties were not correctly copied over during reinstancing.

• Fixed a potential FPropertyTag issue when saving a static array with a property guid.

• Disabled the logging backlog at the end of PreInit for program targets to avoid unbounded backlog growth for programs that do not call GEngineLoop.Init().

• Fixed restarting workers with the incorrect number of task workers if the platform has a thread config. Changed the code to reinitialize with the existing number of workers.

• Fix for CriticallyDampedSmoothing when using target velocity.

• Correctly set ETaskTag::GameThread for the lifetime of the LowLevelTests test runner.

• Fixed initialization of the static thread ID in FTaskTagScope.

• Added a compiler flag to allow the work-stealing task queue to explicitly yield the thread if it fails to steal a job after a certain number of iterations (to avoid a deadlock).

• Fix for a rare memory stomp inside ServerMoveClientError. It is possible for the ServerPredictionData to be nullified part way through this logic (through a delegate fired in MoveComponent), which would mean the ServerData pointer is pointing to stale data. Reacquiring the ServerPredictionData guarantees the data is valid. Fixed a rare memory stomp inside ServerMoveClientError if MoveComponent causes a call to Unpossess.

• Adding FMA intrinsics when compiling with MinimumCpuArchitectureX64.AVX2 on Clang.

  • This fixes a compile error in the Eigen library when compiling AVX2 on Dedicated Servers using Clang.

  • This is because when compiling using the VCToolChain using Clang, we still define _MSC_VER so the Eigen library assumes FMA is included because MSVC always includes those intrinsics when using /arch:Avx2.

  • This change brings our Clang configuration in line with MSVC when using AVX2.

  • Note that this does not change the ffp-contract behaviour, so will not allow the compiler to optimise multiply add operations automatically.

  • Added FMA intrinsics when compiling with MinimumCpuArchitectureX64.AVX2 on Clang.

• No longer reconstructs a subobject after instancing its missing outer if it already constructed the subobject from the source archetype (optimization).

• Fix TPagedArray not forwarding allocator to internal Pages array.

• Remove the IniKeyDenylist and IniSectionDenylist from all layers of the BinaryConfig, instead of just the final InMemoryFile.

• Fixed TFunctionWithContext to support function pointers.

• Added some thread safety to FConfigCacheIni::ReadString (which the others like GetInt go through), SafeReload, and AddDynamicLayersToHierarchy.

• Apply FObjectInitializer instancing exclusions only to the object being constructed/initialized.

• Fixed TFunctionWithContext to support assignment from a const lambda.

• Disable editor-only data for non-editor platforms in FoundationTests.

• Fix duplicate warnings when LoadObject fails and improve the messages.

• Fixed access violation in libcurl 8.12.1 when under heavy load from during cook commandlet. The curl team has already fixed the issue in 8.16 and later.

• Fixed FHashTable buffer overrun on shrinking.

• No longer loads plugin ini files from subdirs (like Tags).

• T Compact Set: Ensure that elements are rehashed after being serialized during reference replacement.

• Fixed a HybridPackageStore init issue when no zen snapshot exists.

  • Fixed some issues with getting PackageStore info when we don't have a package name (in ImportPackagesRecursiveInner sets bHasImportedPackageNames to false).

• Updated UE_LOG_CONTEXT to be safe for use in transactions.

• Task Graph: Fix TGraphTask execute scopes not being emitted to Insights when using lightweight stats. Fix TGraphTask execute scopes not being emitted to Insights when using lightweight stats.

• Removing an unneeded CheckSlow in TCircularBuffer(uint32 Capacity) constructor that was checking for a capacity of 0. FMath::RoundUpToPowerOfTwo returns 1 for both a value of 0 and 1 so the buffer is established with a valid capacity regardless of what's passed in so the check isn't needed.

• When writing out the config file in FConfigFile::UpdateSections, don't write out the file if it matches the current file. This will make it so files like DefaultEngine.ini don't get marked as "changed" by some source control.

  • Slightly changed the COnfigModificationTracker class to be able to use bTrackLoadedFiles more often with worrying about tripping the code to not load a file that was already loaded (reducing side effects of using bTrackLoadedFiles).

  • Now added context in the Console Variables:/[COnsoleVariables_HighPriority] deprecation ensures.

• Fixed missing assignment of OutObjectId in MakeReferenceIds in FObjectHandle.

• Fixed console command arg parsing to support ""

• Added loop break in EarlyPlayFrameTick if engine exit has been requested to fix related hangs.

• F Tick Function Task::DoTask and FBatchTickFunctionTask::DoTask functions' TickContext parameter have the proper TickGroup set (instead of always being TG_PrePhysics).

• Fixed conversion from TArray in FArrayProperty.

• Fix for decltype on angle delta functions.

• Fix bug with FUnitConversion converting values that did not need converting. Resulted in values that were slightly off due to conversion precision limits.

• Fixed an incorrect optimization in FString::MatchesWIldcard and related funcs. It would flag matches incorrectly in certain rare cases.

Deprecated:

• Deprecated functionality in the UE4 API DDC that is no longer supported.

• Deprecated FCoreDelegates::OnPostEngineInit in favor of FCoreDelegates::GetOnPostEngineInit() to fix missing registrations that occur during static initialization.

• Deprecated PLATFORM_ENABLE_POPCNT_INTRINSIC and the associated FPlatformMisc::HasNonoptionalCPUFeatures() and FPlatformMisc::NeedsNonoptionalCPUFeaturesCheck().

• The UObject::Rename flag REN_ForceNoResetLoaders has been deprecated as UObject::Rename will no longer call ResetLoaders or flush loading during renaming as this was the cause of unnecessary loading stalls, and could introduce hard to diagnose bugs due to the sync load in the middle of a possible temporarily, intentionally incorrect UObject state such as during Blueprint reinstancing.

  • Rename will still attempt to maintain a package's Linker export mapping as renames occur unless the flag REN_AllowPackageLinkerMismatch is provided. As a result without specifying REN_AllowPackageLinkerMismatch, Rename will detach the linker from a loaded object whenever the object is moved to a new package.

  • Similarly, renaming a loaded object without specifying REN_AllowPackageLinkerMismatch will detach the export object from the linker that loaded it allowing future package requests for the same package to load a new object instance using the original object name if no object redirector was created during renaming (i.e. REN_DontCreateRedirectors).

  • If an object is being renamed and future package reloads should not create a new instance of original object name, InvalidateExport() should be called on the object before renaming. In cases where one wants to temporarily rename a loaded object and then rename it back to its original name, (REN_AllowPackageLinkerMismatch | REN_DontCreateRedirectors) should be provided as your rename flags to ensure the export is not detached.

• Deprecated PLATFORM_TCHAR_IS_4_BYTES.

Dev Tools

New:

• Unreal Build Tool

  • Support for APX for x64 architecture.

  • Implement.pvsconfig support for PVSToolchain.

• Added TraceQuery, a CLI tool for querying.utrace files as JSONL.

  • TraceQuery is a lightweight standalone UBT program that reads Unreal Engine.utrace binary trace files and outputs structured JSONL to stdout, enabling scripted performance analysis without UnrealInsights or the editor.

  • It depends only on Core, TraceAnalysis, and TraceServices, and decodes named stats, named counter time series, session diagnostics, frame boundaries, and CPU profiler scope events.

  • CPU scope events are buffered per (thread, specId) and flushed as grouped arrays to avoid per-event output for high-frequency scopes. The CLI supports filtering by logger, event name, stat/counter substring, and time range (--start-time / --end-time in seconds).

• Bump preferred MSVC to 14.50.

• Linux HWPGO support.

• Add Raw Pairs to TMap natvis.

• Expose a unique session identifier for each UBT invocation.

• Implement the UAT "-CompileOnly" command line option already documented in the usage info. It will compile all out-of-date script modules before exiting without running any command.

Bug Fix:

• Unreal Build Tool

  • Fix Dynamic Debugging LiveCoding Interaction.

  • Fix sln icon in the shell not displaying vs version, by removing empty first line in sln file.

• Fix ambiguous call converting method group to string.

• Fix RPC InputKey not processing Tapped inputs The Tapped parameter was previously omitted from the RPC arguments dictionary. Created conversion method "AsRpcArgs()" to automatically include all properties decorated with JsonPropertyName, eliminating the possibility of forgetting parameters.

• Make UpdateLocalVersion commandlet write P4 CompatibleChangelist into Build.version.

• UHT: Fix format string when usage in member declaration detected without an alternative, in UhtIssueBehavior.AllowAndLog case.

• Make UAT and UBT out-of-date DotnetDepends checks more robust when launching multiple instances on Windows. The tools themselves check a mutex, but the bat files could previously try to rebuild a tool by before that point.

• Mitigate race condition in ImmediateActionQueue.

• Fixed C# P4 BatchedCommand helper calculating the wrong length and overflowing the 32,699 character limit It wasn't taking into account the length of the base Command or GlobalOptions, which are also added to the arguments when running p4.exe.

Horde

New:

• Horde

  • TokenConfig ClientId and ClientSecret can be read from a Horde secret during configuration load.

  • Added OptionalRequires attribute for BuildGraph nodes. Allow nodes to declare dependencies using the new OptionalRequires attribute, which allow a dependent node's execution to continue if the artifacts failed to be created.

  • When assigning a job lease to an agent check if the required free disk space is available, otherwise assign a conform lease to the agent instead.

Bug Fix:

• Horde

  • Normalize IPv6-mapped IPv4 addresses to plain IPv4 for compute IP comparison.

  • Fixed shelved changelists not being deleted during an agent conform.

  • Dispose the Perforce PoolConnectionHandle when there is an exception during login.

  • Fixed when an agent lease is cancelled by a user the step will complete and upload the logs.

Insights

New:

• Unreal Insights

  • Added keyboard shortcuts for "Find [Max Duration/Prev/Next] Instance" of a timing event in Timing view and Timers view. By default: /,. for [Max/Prev/Next] in selected time range and Shift + /,. for global search.

  • Unreal Insights users can now create time, time range, and event-based annotations in Unreal Insight traces. The annotation data is saved in a sidecar.ini file that can be shared. This feature is to help individuals and teams with the performance analysis of trace files.

  • Added "Go to Frame" (Ctrl+G) and "Go to Time" (Ctrl + T) modals to timing insights. Allows navigation to Render Frame, Game Frame and time stamp.

  • Sort the analysis modules by name when displaying them in the session tab.

• Send OnConnect events on it's own thread. Refactored how events emitted during OnConnect is handled. Events can now be marked as "MaybeImportant" to treat events as important (without retaining in memory) when emitted during OnConnect, but as regular events when emitted elsewhere.

• Added support for tracing through a secured SSL socket. This works slightly differently from the standard socket connection, as the receiving side is expected to connect to the tracing application. The secure connection supports three modes:

  • Self signed certificate and authorization code.

  • Known certificate authority and authorization code.

  • Pre shared key (PSK). Methods of making certificates and authorization codes available on the connecting application is not provided by TraceLog. This needs to be transferred out-of-band.

• Update UnrealTraceServer to v1.24. This adds basic crash handling, and fixes memory leaks and crashes.

• Added API to UE::Trace to expose IsTailing, which allows game code to know if the tail buffer is in use. #[review] [at]fn-perfdev-server Added API call UE::Trace::IsTailing which returns true if the Trace Tail Buffer is active.

• Added "snapshot hitches" feature. This feature relies on the stats system to detect hitches. When a hitch is detected a trace snapshot and screenshot is written to the Saved/Profiling/Hitches directory. Frames are dumped into a directory for each process instance. Start tracking hitches by using in-game console command `snapshothitches -start` and disable by using `snapshothitches -stop`. Requires some stat group to be active, like `stat default`.

• Allow for crashes to contain a trace snapshot. Use cvar "CrashContext.TraceSnapshotOnCrash" to enable and "CrashContext.TraceSnapshotOnCrashTailSize" to set size of tail data to be written. Currently only supported on Windows.

• Add support for controlling max size when writing the tail buffer.

• TraceController now exposes target capabilities.

• Small increase to the time resolution timing shown in insights (without this, values near the low end of the automatic range have almost no precision - e.g. appearing as 1.2s).

• Added OnClose event for when a trace connection is severed.

• Added a MessagingInsights plugin, enabling visualization of UdpMessaging message summaries and lifecycles within Timing Insights.

• TraceLog now automatically emits regular statistics about Trace performance. This can help to analyze problems with Trace performance. They are visualized as counters in Timing Insights.

• Add bandwidth and percent value types for graphs and counter stats.

• Add a "panic mode" for TraceLog. This is triggered if the block pool is full and the TraceLog (worker thread or end frame pump) cannot process data fast enough. When panic occurs the process can continue without being affected, but tracing is no longer reliable and cannot be used for the remainder of the process lifetime.

Bug Fix:

• Addressing several UI/UX bug fixes in the new annotation feature.

• Module names may not contain network names.

• Fix flickering for channel tooltips in the trace control widget.

• Unicast trace status and channel status messages to reduce Trace Control network usage.

• Removed trace started notification from the Editor that affected the trace data.

• Add base file for Insights settings to enable settings persistent in Editor.

Framework

New:

• Level Streaming Persistence (Experimental): Added opt-in support for persisting actor states in a map's persistent level, persisting actor destruction by re-destroying, basic actor respawning (non-time-sliced), and game code hooks. These new features are opt-in and configurable through Project Settings > Level Streaming Persistence.

• Add * and -> operators to TInstancedStruct for convenience.

• ITF: Drop any active mouse hover capture prior to calling `BeginCapture()`. Fix issue where terminating hover cleared the wrong owner field.

• JsonObjectGraph now properly encodes Enums that are being used as Flags.

• Dynamic Loading Range Scaling option in World Settings leading to quicker PIE startup on large maps.

• Add support for interfaces in FWorldConditionContextDataRef binding.

Bug Fix:

• Apply const to query functions that do not perform mutating operations, so they can be used on a const UPrimitiveComponent.

• Added tick unregistration logic to ULevel::ClearLevelComponents to make sure that when incremental unregister is not permitted, tick functions are still unregistered from actors.

• Fixed crash in UBT when reporting Engine Files error.

• Fixed a crash when editing an actor when instances of that actor exist in cleaned up UWorlds.

Deprecated:

• LigthWeightInstances code marked as deprecated.

AI Debugging

New:

• Trace Based Debuggers

  • Refactored and moved TraceSessionsManager from ChaosVD Main changes:

    • Settings are now Attributes to assign/bind when creating the manager.

    • Sessions manager creation now requires explicit references since this is no longer setup as a group of related singletons:

    • Debugger trace runtime module.

    • Engine-editor bridge.

    • Trace module (TraceServices::IModule modular feature)

    • FChaosVDTraceSessionDescriptor replaced by UE::TraceBasedDebuggers::FTraceSessionDescriptor.

    • Moved DataStream related types to (FSessionStreamStatsUpdater, IRemoteSessionDataStream, FDirectSocketStream, FRelayDataStream, etc.) under namespace UE::TraceBasedDebuggers.

  • Replaced recording flag by the ID of the application instance that requested the active recording.

    • Allow recording controls to filter out sessions from the dropdown.

    • Fix message traffic issue by sending the Pong message only to the sender of the Ping (i.e., no broadcast)

    • RewindDebugger controls now filters out other Editor sessions.

    • Fix session naming issue with multiple local editor instances: The session name can only be replaced by "Local Editor" by the process handling the Pong message and not when generating that message since multiple editors can handle it.

• Rewind Debugger

  • Updated FRewindDebuggerTrack::GetStepFrameTimeInternal to use a scrub info struct providing more information to derived classes in order to select the best scrub time to use when using the stepping forward/backward buttons. VisualLogger track now allow users to jump directly to frames with events (i.e., skipping empty frames).

  • Added settings to control the desired transport mode for remote connections.

  • Added a new button to open the folder containing analysis files and one to delete all utrace files in that folder.

  • Added new virtual methods for runtime extensions to register new message types and handlers for remote connections.

    • Added new log categories widget to enable/disable verbosity filtering during recording and control the verbosity of each category (note that the initial implementation populates the "known" categories from the analyzed data of an active recording)

  • Added explicit methods to handle the local session recording and made sure that this functionality doesn't interfere with the other active sessions.

    • When auto-record on PIE is used we make sure to select the local session in case multiple remote sessions are available. Same when resuming or advancing one frame in PIE.

    • Fixed issue where users are not able to start recording while PIE is paused.

  • Added Auto-Scroll functionality.

    • Playback controls are now always available and will disable auto-scroll.

    • Manual scrubbing will disable auto-scroll.

    • Recording started on PIE will activate auto-scroll.

    • Resuming recorded PIE session will reactivate auto-scroll.

  • Added analysis opened/closed notification for editor extensions.

    • Updated some editor extensions to use RuntimeExtension instead when it was the intent (e.g., controlling traces)

  • Added support for remote sessions provided by TracedBasedDebugger/Analysis modules.

    • Updated toolbar to use RecordingControls.

    • Removed SaveTrace command since analyzed sessions are saved to disk by default.

    • Converted VLog filters from checkbox to toggles to allow users to set multiple ones without closing the menu.

    • GameplayProvider no longer filters out Server worlds.

  • Restore previous VLOG recording state when stopping traces.

  • Implement per-provider locking for RewindDebugger trace providers and migrate all call sites from session-level locks to provider-level locks to prevent deadlocks.

    • Add FProviderLock implementation to FAnimationProvider, FVisualLoggerProvider, FPoseSearch::FTraceProvider, FUAFProvider, FAnimNextAnimGraphProvider, FUAFAnimNodeProvider, FChooserProvider, and FStateTreeTraceProvider.

    • Replace FAnalysisSessionReadScope with FProviderReadScopeLock at all RewindDebugger track call sites (~60 files).

    • Replace FAnalysisSessionEditScope with FProviderEditScopeLock in all trace analyzers.

    • Replace Session.ReadAccessCheck()/WriteAccessCheck() with provider-level ReadAccessCheck()/EditAccessCheck().

    • Add missing ReadAccessCheck/EditAccessCheck to provider methods that were unprotected.

    • Optimize lock scopes to minimize hold time (cache data inside tight locks, move widget creation/asset loading outside).

    • Wrap Session.UpdateDurationSeconds() calls in FAnalysisSessionEditScope where needed.

  • Add configurable allowed class types filter to the Rewind Debugger target selector Replaces the hardcoded ULevel/UWorld child filter in the object selector dropdown with a configurable allowlist of class types.

    • Adds a new URewindDebuggerProjectSettings class (project-scoped, saved to RewindDebugger.ini) with a SelectorAllowedTypes array, defaulting to AActor.

    • Extends URewindDebuggerSettings (user-scoped) with a matching SelectorAllowedTypes array that can add types on top of the project settings but not override them.

    • The selector now filters by checking IsSubClassOf against the combined allowed types; an empty list falls back to allowing everything.

    • Renames URewindDebuggerSettings display name to 'Rewind Debugger (user preferences)' and fixes VLog settings to use its own localization namespace to avoid collision.

• Visual Logger

  • Introducing new defines to split functionalities: Recording, Rendering and Visualizer Tool.

    • UE_DEBUG_RECORDING_ENABLED: Indicates whether the UE_DEBUG_* macros will record the element (VisualLogger and/or insight traces).

    • UE_DEBUG_RECORDING_USING_VLOG: Indicates whether the UE_DEBUG_* macros will use the VisualLogger recording process to store entries and write to all registered output devices. Otherwise only insight traces are used.

    • UE_DEBUG_RENDERING_ENABLED: Indicates whether the UE_DEBUG_* macros will use immediate debug draw visualization.

    • UE_DEBUG_VISUALIZER_TOOL_ENABLED: Indicates whether the analysis of the recorded data is active and dedicated UI and tools should be compiled.

    • To maintain compatibility ENABLE_VISUAL_LOG will enable all three functionalities. Without UE_DEBUG_RECORDING_USING_VLOG we bypass most VisualLogger functionalities to log to the trace directly. Examples of disabled features:

      • CategoryAllowList

      • NavigationDataDump

      • DebugSnapshot

      • ClassAllowList

      • ObjectAllowList

      • Output devices.

  • Added opt-in functionality to apply LogCategories verbosity filter when recording. Can be controlled by:

    • Console commands: Vislog.ActivateVerbosityFilterWhenRecording and vislog.DeactivateVerbosityFilterWhenRecording.

    • Config Property `bUseVerbosityFilterWhenRecording` in VisualLoggerSettings.

• IMessageBridge

  • Add IsSubscribed(FTopLevelAssetPath) pure virtual to the base IMessageBridge interface so any bridge implementation can report whether it forwards a given message type.

  • FMessageBridge (standard) returns true unconditionally (PATHNAME_All).

  • Add FOnSupportedMessageTypesChanged multicast delegate, broadcast whenever the supported message types list changes (from RegisterExternalSupportedMessageType, InitializeMessagingSystem, or any path through ReInitializeMessagingSystem).

  • Add SetMessageBridge() to store an external bridge reference for per-type reachability queries.

  • Add CanPublishToNetwork that checks for a standard bridge (INetworkMessagingExtension modular feature) or queries the custom bridge's IsSubscribed for the specific type.

  • Gate SendPong on CanPublishToNetwork<FSessionPong>() to prevent ghost sessions when no bridge can forward Published messages back to the controller.

• SmartObjectComponent Uses GetActorDescProperties.

Bug Fix:

• Rewind Debugger

  • RecordingStarted is now called immediately once the connection gets established (not deferred to game thread) since the channels need to be enabled before the next game thread frame to not miss events.

  • Made sure that world times got reset before enabling trace channels from OnEnableRequiredTraceChannelsInternal virtual method.

• AI Blueprint Helper: Updated CreateMoveToProxyObject to make sure the controller is still a valid Actor that can be stored in a weak pointer.

• Visual Logger: Updated trace output device to handle entries larger than the maximum trace event size.

• Fix: GetSmartObjectBounds was getting the owner actor transform instead of the component one.

• Gameplay Debugger Replicator fixes to work with the MultiServerProxy. Gameplay Debugger Replicator used indices to replicate (which wouldn't necessarily match the other server). Now using names when available, Extensions are still by index.

• Config: Added ensure and recovery code when a config is created and the 'config' specifier is missing on the UProperty.

AI EQS

New:

• Added the bStripFromClientBuilds option to UEnvQuery, mirroring the pattern on UDataTable. This allows EQS assets to be excluded from client builds, since they are server-only AI queries.

AI Navigation

New:

• Mass Navigation

  • Added OffsetCornersFromBoundaries parameter to FMassNavMeshPathFollowTask to push wall-hugging corners away from walls.

  • Improved Mass navmesh path-follow end-of-path detection with combined distance and projection checks; also fixes a division-by-zero.

  • Added FAgentHeightFragment to additional Mass StateTree tasks (FindSmartObjectTarget, NavMeshPathFollow) that need a height to query the navmesh.

  • Added FAgentHeightFragment requirement to FMassNavMeshFindReachablePointTask so it can build a valid FNavAgentProperties for queries.

• Nav Mesh

  • Optimized Detour navmesh link memory by sizing the base link pool to actual usage (~30 MB savings on large maps); exposed bMinimizeLinkPoolSize and added link utilization stats to DumpNavMeshMemory.

  • Optimized navmesh vertex storage by packing vertices as tile-local float offsets (~50% memory reduction on vertex data); navmesh version bumped to 28 with automatic legacy-format upgrade on load.

  • Fixed misleading description and tooltip on ARecastNavMesh::bForceRebuildOnLoad.

  • Exposed ARecastNavMesh::AverageLayersPerTile and reduced its default value, saving memory in the tile pool allocation.

  • Skipped BVTree creation for navmesh tiles with very low polygon counts to save memory.

  • Added bDrawOnScreenInformation on ARecastNavMesh to toggle on-screen detailed navmesh information.

  • Optimized FRecastNavMeshGenerator::RemoveTiles to reduce a hang when many tiles are dirty simultaneously.

  • Nav Area:Nav Mesh: Added per-mesh custom NavArea support on UNavCollision (bUseSurfaceArea + AreaClass) so static meshes can apply custom walkable area costs during rasterization.

• Navigation System

  • Change to how Pawns without a PreferredNavData set work. This makes it so, if unset, that the Pawn will now only find and use NavData with matching CanFly values. This prevents ground-based Pawns from trying to use flying navigation data.

  • General navigation log improvements (clearer messages, better contexts).

  • Added diagnostic logs on AddNavigationSystemToWorld, OnWorldInitDone, GetWorldBounds, PerformNavigationBoundsUpdate, OnLevelAddedToWorld and ANavigationData bound changes.

• Avoidance: Added configurable side-bias threshold and right-side passing bias to Detour crowd avoidance.

• Added logs that record AsyncLoadLock state and increased verbosity in navigation tests to help diagnose intermittent failures.

• Added the navdata name to navdata registration logs. Added a log when navigation building is prevented by a navigation lock.

• Navigation: Exposed GetLengthFromPosition to Blueprints.

• Removed UE 5.5-era deprecated navigation code.

• Mass Avoidance: Mass avoidance gameplay debugger can now display entity radius when no collider is present.

• UEFN now dirties the package on navigation generation completion so changes can be saved.

Bug Fix:

• Navigation System

  • Fix data race in RegisterNavRelevantObjectInternal when using async nav data gathering. When bDoFullyAsyncNavDataGathering is enabled, FRecastTileGenerator::DoWork() runs on a worker thread and reads FNavigationElement fields via FNavigationRelevantData::SourceElement (a TSharedRef<const FNavigationElement>). Concurrently, the game thread can call RegisterNavRelevantObjectInternal (e.g. when a component is registered a second time) which overwrites the same FNavigationElement in-place through a mutable TSharedPtr. The root cause is that the repository stores TSharedPtr<FNavigationElement> (mutable) and overwrites in-place, while all other holders (navigation octree, pending updates, tile generator) hold TSharedRef<const FNavigationElement> to the same heap object, assuming immutability. Fix:

    • RegisterNavRelevantObjectInternal now allocates a new FNavigationElement and replaces the map entry via Emplace, instead of overwriting *ExistingElement. The old instance remains alive and unchanged as long as the octree or an in-flight tile generator holds a reference to it via SourceElement.

    • F Navigation Octree Controller::RemoveChild now compares children by FNavigationElementHandle (UObject + SubElementId) instead of TSharedRef pointer identity. This ensures that passing a newly-allocated element for the same navigation object correctly finds and removes the old entry from OctreeParentChildNodesMap.

  • Fixed reentrance in UNavigationSystemV1::RegisterNavData that could trigger when registration callbacks spawned new nav data.

  • Now waits for initial async loading to complete before triggering an automatic rebuild; new bWaitForAsyncLoadingBeforeBuildingNavigationAutomatically property controls the behavior (enabled by default).

• Navigation

  • Fixed an intermittent issue where off-mesh connections could be missing after navmesh generation, depending on the order tiles were processed.

  • Fixed an issue where deleting the last NavMeshBoundsVolume in a level could leave the navmesh in a null state, causing subsequent property edits to trigger an ensure. The navmesh is now preserved when there is no longer anywhere to build navigation, and any stale tile data is cleared instead.

  • Fixed an issue where traveling to a level that had a navigation bounds volume but no saved navigation data would leave the navmesh empty, preventing NPCs from pathfinding. The navigation system now correctly triggers an async rebuild when it spawns fresh navigation data at runtime.

  • Fixed an issue where NavLinkProxy actors used by Child Actors did not work correctly on startup in Play in Editor.

  • Fixed an issue where area costs were not set before NavLinks were snapped during level serialization.

  • Fixed an issue where a NavLink Proxy could fail to register when the navigation system was not yet initialized.

  • Fixed several issues with directional generated NavLinks:

    • Fixed an issue where generated NavLinks were not applied to the correct layers when directional links with different areas were present.

    • Fixed an issue where directional NavLinks were not height tested.

    • Fixed an issue where reversed NavLinks were stored incorrectly. Directional up links are now stored in reversed order to keep them with their associated down link, and the owner position is now correctly validated to be contained by the tile when handling asymmetric border sizes.

  • Fixed an issue where the AllowLinkGeneration console variable was not enforced uniformly across all navmesh generation paths.

  • Fixed an issue in Recast where generated data was not placed where the caller expected it.

  • Fixed an issue where EncompassesPoint did not work correctly on ANavMeshBoundsVolume.

  • Fixed an issue where spline points were generated in world space instead of local space, causing the world transform to be applied twice.

  • Fixed an issue where a component could remain in the navigation octree after being unregistered.

  • Fixed an issue where navigation bounds were not cached correctly before being registered, which could trigger an ensure.

  • Fixed an issue where undoing or redoing changes that required a navmesh rebuild were not being detected correctly. The navmesh now responds to PostTransacted notifications to catch these changes.

  • Fixed crash in AddNavigationSystemToWorld during Sequencer undo/redo on transient worlds.

  • Crash Fix: [Navigation] Fixed a crash that occurred when an extreme JumpLength value was set in a NavLinkJumpConfig. The inflated tile border size could cause an allocation failure or integer overflow during navmesh generation. A warning is now logged when the border size exceeds the tile size, and tile generation is safely aborted if the heightfield size would overflow.

  • Fixed ensure when editing NavigationSystem config properties in Project Settings by skipping CDOs in FEditorViewportClient::OnObjectTransacted.

• Nav Link

  • Fixed multi-config registration for generated navigation links.

  • Fixed an ensure in ComputeCustomLinkBounds.

  • Fixed crash in ANavLinkProxy::GetComponentsBoundingBox.

  • Fixed an ensure that triggered when undoing a NavLinkJumpConfig change that had a LinkProxyClass set.

• Nav Mesh

  • Fixed navmesh loading quantization factors not matching newly-updated CellSize settings (occurred when settings were changed via config files outside the editor).

  • Detour dtNavMeshQuery::queryPolygons now handles out-of-memory conditions gracefully.

• Newly created Blueprint NavArea classes are now registered via PostCDOCompiled so they take effect without a reload.

• Automated Testing: Fixed an issue where AutomationLoadMap started Play in Editor immediately after loading a map, copying an empty navmesh into the PIE world before the async editor rebuild could finish. PIE startup is now deferred until the editor navmesh finishes building.

• Fixed multithreaded access on FLandscapeHeightfieldCollisionComponent::CachedHeightFieldSamples reachable through INavRelevantInterface::GatherGeometrySlice.

• Prevented a crash when exporting geometry containing too many triangles for navmesh generation.

• Fixed navigation data not being removed when using One File Per Actor (external actors).

• Fixed "Build > Build All Levels" leaving the navigation system in a broken state.

• Fixed navmesh being out of sync with unloaded objects in World Partition maps when Build Paths is run.

• Ensured the map package name is known before building a World Partition navmesh in the editor so the map can be reloaded afterwards.

• Fix FCompositeNavModifier::CreateAreaModifiers not taking into account FKSphylElem internal rotation Fix FCompositeNavModifier::CreateAreaModifiers not using the proper length for a FKSphylElem Fix FAreaNavModifier cylinder constructor not handling non vertical cylinders. This will now fallback to a box if the cylinder is not vertical.

• Fixed ai.debug.nav.DirtyAreaAroundPlayer debug command not working on the server.

AI State Tree

New:

• State Tree

  • Property Binding Utils:

    • Added a cvar to control automatically removing failed-to-resolve source binding path bindings or not for State Tree. Default true(old behavior). Missing target struct binding path bindings or failed-to-resolve invalid target binding path bindings will always be removed automatically. Missing source struct binding path bindings will never be removed automatically.

    • Fix up State Tree Editor Bindings when UserDefinedStruct, Blueprint, or UObject gets reinstanced from live coding. Cache dependency to filter out state tree assets.

    • Correctly gather dependent structs for compiled property bindings.

    • Use struct's authoraritive version when resolving indirections.

    • Bindings display friendly name for UserDefinedStruct properties.

  • Added option to override start state by gameplay tag when starting running the tree. States corresponding to the same gameplay tag will be searched through in breadth first order.

  • Do not create an instance data storage for shared instance data when no shared data exists. It reduces the runtime memory footprint. Each thread that access state tree increments a counter. That counter is static and is valid for all state tree assets. That means each state tree asset uses a ?number of threads? amount of storage, even if the state tree asset is not intended for threading.

  • Add a queue and asynchronous state tree compilation. The compilation is always on the game thread. The state tree asset is compiled "just in time" the first time it is used by the game. The features are disabled by default.

    • With cvar StateTree.Compiler.EnableQueuedCompilationOnAssetLoad, the public step will be compiled synchronously when the asset loads, and the internal steps will be queued for later. Without the cvar enabled, the previous behavior is maintained. The compilation of the public and internal steps are compiled synchronously.

    • With cvar StateTree.Compiler.EnableQueuedCompilationWhenAssetDirty, the asset is queued for compilation as soon as it is modified in the editor.

    • With cvar StateTree.Compiler.EnableCompileSynchronouslyInPIESession, all queued assets are compiled synchronously before a PIE session starts. While in PIE, assets will not be queued. They are compiled synchronously.

    • With cvar StateTree.Compiler.NumberOfQueuedCompilationPerBatch, you control how many state tree assets compile per ticking loop. To deactivate, set to 0. Every tick, the engine will compile NumberOfQueuedCompilationPerBatch queued state tree assets, including the dependencies.

  • Refactored and fixed incorrectly accessing subtree parameter, global parameter and global instance when it exists in a parent frame multiple levels above.

    • Now we cache corresponding Parent Frame IDs for accessing global parameter and global instance in temporary data, and cache corresponding index base for accessing global parameter and global instance in active instance data.

    • No longer sets Subtree and Global Parameters in UpdateInstanceData because they have already been set when creating the frames and they don't change. We update ActiveInstanceIndex, GlobalInstanceIndex and GlobalParameterIndex in UpdateInstanceData.

  • Enable evaluation scope by default. Tell the cooker about the cvar that can affect the compilation result.

  • Implement EvaluationScopeInstanceData for condition's EnterState/ExitState/StateCompleted.

  • Remove STATETREE_POD_INSTANCEDATA in favor of UE_STATETREE_CONSTRUCTED_TRIVIALLY_COPIED_NO_DESTRUCTOR_INSTANCEDATA or UE_STATETREE_ZEROED_TRIVIALLY_COPIED_NO_DESTRUCTOR_INSTANCEDATA. Properties that are initialized in-place need the constructor. ScriptStruct instances constructed from script (BP or StateTree instance data) are memset to 0 by default. The POD has a different meaning in C and CPP (pre 2020). It is preferable to use the more descriptive term "trivial" to identify types that can be trivially constructed and copied.

  • Allow creating new StateTree assets from linked asset dropdown.

  • Create UE::StateTree::EComparisonOperator to replace EGenericAICheck from the AIModule. This is an effort to make StateTree not depend on AI modules and make it generic for everyone to use.

  • Implement drag and drop for state tree state nodes Extending the existing drag and drop structure to support dragging state's nodes around. By default, dragging a node moves it to another state (literally moving) keeping the bindings valid if any other node references it's properties. By holding Ctrl key while dragging, the behavior alternates to copy instead move.

  • Added FStateTreeExecutionContext::GetCurrentlyProcessedStateSelection.

  • Prevent linked state override when bindings could use invalid data.

  • Hide utility consideration when they are not usable. The parent needs to have a selection behavior that uses them.

  • Access ExecutionRuntimeData from async task.

  • Add a color bar that matches the category color.

  • Chained Property Ref from multiple parent frames above can now correctly fetch source data. Now we fetch the associated parent frame that stores GlobalParameter or SubtreeParameter by FrameID.

    • Disabled using PropertyRef in ExternalGlobalParameterData.

    • Deprecated and refactored FindFrame.

    • Deprecated and refactored FStateTreePropertyRef::GetMutablePtr.

    • Deprecated StateTreePropertyRefExternalHandle.

  • Execution context uses a view instead of the property bag. Deprecated the property bag version. This is a step to use a permanent script struct instead of the transient property bag.

  • Add menu action to select the transition's target state.

  • Add new transition targets. Parent, NextParent, and NextSelectableParent. They are reconciled at compile time and work similar to NextState and NextSelectableState.

  • Added a button to remove all elements from the tasks, evaluator, condition, transition lists.

  • Added a button to remove all properties from the property bag.

  • Move the temporaries before it is used in EnterState. Previously, they were all moved in UpdateInstanceData. It caused a problem if an async task requested the instance data before the state was added to the Frame. Usually, that could not happen, but global nodes (task and evaluator) can be started temporarily. Their EnterState is called, and they will only be added to the frame when the linked state is added.

  • Add a global callback and a callback on the editor extension to validate the state tree asset. The validation occurs when the asset loads, and before it compiles. The user can use the callback to modify the editor data before the asset compiles.

  • Add a condition to compare a single Gameplay Tag against another.

  • Capture condition / task / utility names in ST rewind debugger.

    • Add IStateTreeDebugInfoProvider to provide editor data driven debug info when possible, with default runtime only debug info as fallback.

  • Add ability to mark a transition for reselection.

• Added Experimental State Centric View.

  • Disabled by default. Enable via `StateTree.Editor.Experimental.EnableStateCentricView`

• Show number of enter conditions / tasks / transitions / considerations / parameters in details header.

  • Also show utility weight if it's just a weight.

Bug Fix:

• State Tree

  • Recursively Trigger transitions from parent frame when a subtree completes. This solved issues caused by When hit the max iteration, the execution context will lose track of info in the next frame when continuing transition processing from the subtree completion.

    • Added unit test to verify this.

  • Fixed an issue where events are not visible to the state required event to enter from on completion transition. Fixed an issue when a subtree completes, broadcasted delegates and events will be incorrectly cleared.

  • Remap state event IDs when cut/paste states Preserve and remap state event IDs during copy/paste to fix compilation failures when a pasted state has nodes that bind to required events on the state's enter conditions.

  • Fix crash in Enum Compare Condition when resetting right field default value.

  • Events added during TriggerTransitions will be queued and only reset in the next TriggerTransitions. This allows multiple parallel trees to share event with each other, and fixes events sent in task on enter won't be accessible in the next tick in parallel trees.

  • Prevent Linked Asset override at runtime when the Linked State Parameter is binding source or binding target. This includes the parameter is bound to something else, a node is bound to the parameter or a node's appended property function is bound to the parameter.

    • Use an additional flag for override. Cache the flag during Compile for runtime check.

  • Disabled Promote to linked state parameter option.

    • Fixed an issue where property cannot be promoted to state parameter if state parameter is empty.

  • Disable promoting to state parameters if the state is a linked state.

  • Correctly Scope Start and Stop global tasks debug phase. Global tasks are entered/exited hierarchically and each frame should have its own scope to reflect the correct ordering.

  • Fixed an issue where transition delegates weren't triggered if the delegate was broadcasted during the transition tick.

  • False positive circular reference while compiling state tree asset async. This occurs when A refers to B and C. And B also refer to C.

  • Fix issue with override linked asset when the state needs reentrance. It used to pick the new override for sustained transition instead of picking the previous override. Add unit test for 2 repro of that same bug.

  • Make status not trivially copiable. The inner pointer might point to itself. Unreal container do use trivially allocated structure. They do not call the move or copy constructor.

  • Fixed states order is reversed when inserting before another state in the editor.

  • Remove the temporary instance data once it has been consumed. Previously, all temporary instance data was moved in UpdateInstanceData. Now, they are only moved when the task starts.

  • Only append temporaries when they will not be copied later in Enter. This fix issue introduced with.

  • Add callback to get the asset registry tags from the editor data. Use the editor schema to always have a valid schema in case the compilation fails.

  • State Tree Debugger: Added support for breakpoints in statically linked assets (i.e., not dynamic overrides).

    • Asset no longer get dirty when adding/removing breakpoint.

    • Select the first available instance in the debugger view when analysis starts.

  • Property Binding Utils:[State Tree] BindingView rework.

    • Added error icon for Missing struct.

    • Added error icon for binding path failed to resolve.

    • Click on Binding struct will traverse to the corresponding struct property row.

    • Click on Binding path will traverse to the corresponding property property row.

• Fix issue where we use stale linked state tree override whenever there is a change overrides in the middle of the current context's execution Since we are only allowed to set linked state tree overrides before we start context's execution, it is not possible to update it when an override changes sometime between the start and the end. To fix this we use a delegate to fetch current state tree overrides from external source.

• Fix rename failing on to be discarded ST editordata schema object.

Blueprint

New:

• Blueprint "enable/disable" node submenu options moved out of experimental. Right-clicking on a node with exec pins will now present options to enable or disable the node, without having to opt-in to this behavior.

• Blueprints: Make FVector2D default values work when exposed on spawn on the Construct Object BP node.

• Added simple counter to ensure if too many Blueprint async actions are created. The number of allowed actions can be set using the console variable `bp.MaxAsyncActionCount`. Set the number to <= 0 to disable the ensure.

• The Blueprint editor scripting API has been greatly expanded. For editing Blueprint graphs use the new BlueprintGraphEditor. For general Blueprint editing see the new functions in BlueprintEditorLibrary. If you're unfamiliar with these APIs consider running help(unreal.BlueprintGraphEditor) or help(unreal.BlueprintEditorLibrary) in your python console.

• Expose FPerPlatformBool to Blueprints to match Int and Float.

• Find in Blueprint: Will now search keys in the default key-value pairs in Blueprint Map variables. Previously only Map values were searchable.

• Struct Utils: Add helper functions to generate a UserDefinedStruct from a property bag. Property Bag are great when used internally the same package. It can cause issue when there's a reference outside the package. UserDefinedStruct are better at handling those.

Bug Fix:

• Fixed Blueprint function local variables being allowed to have the same name as member variables, which led to default value inheritance problems. Name validation is properly applied now when naming local variables. Name collision was already properly checked for member variables.

• Fixed crash when loading Blueprints with ComponentClass overrides.

• Fixed crash when deleting a character Blueprint and anim Blueprint at the same time.

• Fixed crash when pasting a component into a Blueprint.

• Fixed ensure when changing the class of a scene component.

• Structure assets will no longer causes crashes if deleted when they are used as member variables in Blueprints.

• Change K2Node::GetBlueprint to possibly return null (expected by most callers), and add GetBlueprintChecked for the old behavior.

• Fix several Blueprint editor crashes that would happen when recompiling at an unexpected time.

• Fix crashes when trying to reparent a Blueprint to a temporary class like a python wrapper, these are no longer shown as an option.

• Fields and properties associated with transient, non-native uclasses are no longer shown in the Blueprint context menu, as when placed in a graph they will not be able to resolve themselves when the asset is loaded.

• Fixed issue looking up default values for the root component when it is named DefaultSceneRoot.

• Fixed crashes in FBlueprintActionFilter::IsFilteredByThis.

• Component reference picker improvements: Allows picking components in the Blueprint editor.

• Fixed one cause of the prolific "PinHelpers::UnresolvedPins.Num() == 0" warning message.

• Fix bug where drag and drop could create an invalid floating point node.

• Nested split pins no longer cause data loss or assertion failure when their backing schema (Struct or Function) is changed.

• Correctly warn about trying to delete in-use local variables.

• U Subobject Data Subsystem::AddNewComponent will no longer crash when adding components without an explicit Blueprint context.

• Component subobjects tagged as RF_ArchetypeObject now have their subobject flags conformed, forcing RF_Public and consequently preventing 'linked to private object' error.

• U Blueprint Editor Library::GetBlueprintAsset now looks for adjacent UBlueprint objects, e.g. if a Level asset is provided as the object to get the UBlueprint from.

• Fix issue where properties like skeletal mesh would be reset after Blueprint duplication.

• Fix several editor crashes when trying to load invalid Blueprint assets.

• Fix crash when trying to set a local variable named the same as a replicated property.

• Fix issue where copy-pasted Blueprint nodes would no longer be pure.

• Fix bug where data assets made from Blueprints had the NativeClass asset registry tag set to the Blueprint instead of the parent native class. This will be fixed the next time those assets are resaved.

• Fix bug where undoing a child actor component deletion could create duplicate actors.

• Fixed a bug where changing a UUserDefinedStruct used in an FInstancedStruct property of a UDataTable row, would not re-instance the structs (as they do in non-UDataTable cases), causing data table details panels to crash trying to read new fields in the now-outdated instance memory.

• Fix missing native/instanced struct value data on runtime-spawned BP actor types with "Generate optimized Blueprint component data" enabled.

• Fix bug where Child Actor Class could not be set back to none in child actor components.

• Fixed Blueprint default properties with custom property customization not using the correct IsEnabled value in certain cases.

• Fix crash trying to compile a variable set mode pasted from another class.

• Struct Utils: Fix dirtying and recompile property bags when a UserDefinedStruct is modified.

• Fix Set Fields Blueprint node to accept non-const reference parameters.

• Output pins on Blueprint result nodes are once again validated for uniqueness when being edited.

Blueprint Compiler

Bug Fix:

• Blueprints are now compiled in the order their class taxonomy will define, rather than the one they currently define - this fixes crashes when compiling Blueprints after changing their parent class.

• Macro nodes no longer raise unsupported Blueprint changed notifications during compile, fixing crashes when compiling some Blueprints with complicated macros.

• Blueprints loaded for diffing will no longer attempt to compile before PIE, even if they have been marked as dirty.

• Guard against potential attempts to reinstance non-Actor objects with an invalid outer.

• Fixed rare non-determinism in Blueprint generated bytecode caused by text values that matched their default string.

• Blueprints that are in a dirty state because they are using a Struct that has been modified are now automatically recompiled on save.

• Fixed rare crash when compiling Blueprints with invalid functions.

Blueprint Runtime

Bug Fix:

• TScriptInterface now only produces a valid value if the provided object implements the specified interface (either as a Blueprint class or natively).

• Fix race condition between UPrimitiveComponent::Postload and FObjectInitializer::InitProperties when instantiating a BP while its CDO is completing its initialization on the Gamethread.

Gameplay

New:

• Input

  • FInputDeviceScope refactor and deprecation.

    • Deprecation the FInputDeviceScope type. Instead, you should use the new FInputDeviceRegistry type instead. This registry is thread safe and removes the need for Input API's to wrap every event with a FInputDeviceScope, which is very error prone and confusing.

    • The FInputDeviceRegistry should be populated any time a new device is *connected*, and has an assigned FInputDeviceId. This way, the device name/type is evaluated once, upon connection, instead of every single tick.

    • Effectively make the FInputDeviceScope no-op unless the UE_USE_LEGACY_INPUT_DEVICE_SCOPE define is set to 1. Users can define this in their Target.cs file if you still depend on FInputDeviceScope.

    • For forward compatibility, when a device is connected (IPlatformInputDeviceMapper::Internal_MapInputDeviceToUser is called) if there is not already a new device registry entry available, we will attempt to populate it from a device scope that is available.

    • Enforces a better contract for the FInputDeviceId to each platform and makes them all consistent.

    • Linux and Mac were completely missing FInputDeviceScopes, and they now have a FInputDeviceRegistry call to resolve that.

    • In CommonInput and the Input Device Subsystem, utilize this new FInputDeviceRegistry instead of FInputDeviceScope's. The names of the types for common input should be the same, and do not require asset updates. Same with the hardware device identifiers.

  • Add some debug data to player input available in non-shipping and test builds behind the UE_PLAYER_INPUT_INCLUDE_DEBUG define.

• Mover

  • Updated README documentation, accounting for bugfixes and feature set changes.

  • Populating/refreshing shared settings in OnRegister of a Mover component so we guaranteed have valid shared settings.

  • Reworked kinematic simulation to be separate from MoverComponent, as a stepping stone towards using Mover with non-Actors.

  • Removed unsupported PhysicsMover / NetworkPhysicsLiaison code from Mover plugin, in favor of ChaosMover plugin.

  • Support perching radius threshold so characters can be configured to fall off ledges if they're only partially supported.

  • Add MixMode parameter to Play Mover Montage BP node, for control of how the root motion mixes with other movement sources.

  • Added a BP-friendly method of querying for the floor so it's easier to include in Blueprinted movement modes.

  • Exposing the movement base's transform deltas through an update event, in support of motion matching while on a moving platform.

  • Implementing MovementInterface on UMoverComponent and using the interface in encroaching checks so we also use the movementcomponent path and properly check encroachment when using a mover component.

  • Evaluating Mover instant effects after modifiers are added/removed. This helps crouch apply properly without any depenetration. Also adjusting the stance modifier to always adjust capsule location when modifying capsule size.

  • Add residual velocity when leaving a movement base.

  • Reworked kinematic based movement to eliminate drift on rotating, tilting platforms similar to heaving boats.

  • Adding a projection setting to nav walking modes that allows users to specify what geometry to project to in relation to the navmesh. Also adding proper support for move off navmesh option for NavWalkingMode.

  • Adding an ensure to navwalking modes noting that the bAllowClientSideNavigation navigation system setting needs to be true if nav walking mode is running on a client so a navmesh is available for nav walking to use. This is the case when running a pawn in nav walking mode with Fixed Tick Forward Predicted Network prediction simulation.

  • Added helpers for common rollback blackboard entry creation cases, and current-frame-only persistence option.

  • Added simulation context as a parameter to core Movement Mode functions.

  • Added query for the next anticipated movement mode.

  • Adding RVO interface to NavMoverComponent to support detour crowd avoidance. Note, this is not force based RVO avoidance. Also adding some example content to mover examples to show this functionality.

  • Remove unnecessary falling check that will never get hit in movement utils.

  • Added prediction mode support for the rollback blackboard, so trajectory prediction flows can read/write with it without affecting the true simulation state.

  • Add USimpleFlyingMode to simplify the process of making a Blueprint driven flying mode.

  • Made all default movement modes function with non-capsule shapes as long as they're reasonably symmetric within the movement plane.

  • Added support for single-entry values in the rollback blackboard, along with a policy to ignore rollbacks.

  • Mover, ChaosMover: Added more time step information to event data, allowing differentiation on factors like whether a resimulation is occurring.

  • Mover, ChaosMover: Added more contextual information to time steps and events.

  • Network Prediction and Mover: Expanded ShouldReconcile to allow the option of deferring to a simulation driver function.

  • Mover Examples: Adding example map to help test scaling to larger NPC counts.

  • Add Mover Methods to query if a tag exists. Add Mover FSM nullptr checks.

• Level Streaming Persistence Plugin

  • Exposed persisted property configuration to editor as DeveloperSettings.

  • Exposed the LevelStreamingPersistenceManager's SerializeTo and InitializeFrom functions to Blueprint. SerializeTo now updates persistence data for visible levels, ensuring that the in-memory cache is up to date for all levels of the map before serializing to a binary blob.

  • Now shows warning in editor when a persisted property is missing editable specifiers.

• GAS

  • Add RemovalPolicy to OnApplicationGameplayEffects, incorporated in AdditionalEffectsGameplayEffectComponent.

    • Use case: Control life time of external applied GE through GE that applies it conditionally. I myself have noticed this before, and I've seen bugs in the past from designers not understanding that a GE applied through a GE controls its own lifetime by default, they implicitly assume it will be removed when the effect which applies ends.

    • Added support for removal policy, following a very similar pattern to Granting GAs through a gameplay effect component (You can cancel / end the GA when the GE granting the ability is removed).

    • Added EGameplayEffectGrantedEffectRemovalPolicy enum (GrantedEffectControlsOwnLifetime, RemoveGrantedEffectOnEnd).

    • Added stack count to remove field to conditional gameplay effect.

    • OnActiveGameplayEffectRemoved removes any on-application effects whose policy is RemoveGrantedEffectOnEnd.

    • Added content validation: Error if RemoveGrantedEffectOnEnd is used with an Instant owning GE or an Instant granted GE Updated AdditionalEffectsGameplayEffectComponent to support controlling lifetime of granted GEs.

  • FActiveGameplayEffectHandle now holds a reference to its Owning AbilitySystemComponent rather than using a Global Map.

• Remote Objects

  • Introduced AActor::GetPreferredRemoteServer to allow Actors to migrate together (e.g. Controller depends on Pawn's Location).

  • Fixes that allow parts of the AbilitySystemComponent to work with object migrations and multi-server proxy.

• Cameras

  • Make playback mode only affect whether a GPC component writes to the output component Don't make it affect whether a standalone camera system is created or not. This makes it easier to manage, and easier to understand for the user.

  • Some errors and warnings shouldn't be reported when running editor previews.

  • Rename AutoActivateForPlayer to DefaultPlayer, and simply always use that unless anything else is specified.

  • Add "playback mode" to the GPC components This allows GPC components to be recorded by Take Recorder. The output camera component is also recorded, and upon playback, the new "playback mode" option can be enabled (similar to how physics should be disabled on recorded actors). This lets the output camera component be animated by the recorded keyframes, without the GPC system interfering.

  • Add a sprite icon to GPC components This makes it easier to locate the GPC component in the scene when the output camera is offset from it. The sprite is hidden when the output camera is close or on top of the root location.

  • Allow using an "output" camera component created in the parent actor.

    • Actor components cannot create visible/editor-friendly children components themselves. Component hierarchies need to be created by the actor. This change moves the creation of the "output" camera component to the parent actor.

    • The GPC component only creates it if they can't find one created by the actor, which can happen if the GPC is inside another actor who doesn't know about all this, such as a character pawn or any other Blueprint. The user can still get this output camera component to be visible by creating it themselves and parenting it under the GPC component.

    • Since this effectively changes the output camera component from a "hidden" implementation detail to an "official" component of the actor, it would now show up in the Details View of the actor by default, cluttering up the UI with irrelevant properties that get overridden by the camera system evaluation. So this change also tweaks the categories and metadata on a few properties to make sure this component is hidden from the actor's Details View.

  • Expand documentation and add UI min/max settings to the field of view node.

  • Add explicit checkboxes to the lens parameters node Instead of specifying zero or negative values to indicate that some property should be ignored, there are now explicit checkboxes to enable/disable each lens parameter.

  • Add support for first person view.

    • Add new properties to the camera pose for 1P views.

    • Add a new 1P node to set those properties.

  • The node parameter detail customization now supports several property metadata like min/max values or units.

  • Add option to run camera directors and Blueprint camera nodes in editor.

  • Add action that aims at an actor with optional bone/socket.

  • Add a time-out property to camera actions Also simplify a bit how actions get cleaned-up, and the properties that need serialization.

  • Extract most of the "Aim At" action logic into a base class to make it easy to create other types of aiming actions.

  • No longer finds referenced objects from too many packages when gathering director usage The StateTree and Blueprint directors figure out what camera rigs and proxies they use by simply looking at referenced objects up to a certain distance.

    • However, this reference gathering was a bit too heavy handed. This change skips compiled packages, and adds an option to not explore objects of certain classes. This helps drive down the amount of referenced rigs and proxies shown in the "family shortcuts" in the editor (which showed seemingly unrelated assets).

    • It also fixes a bug with camera assets being dirtied on PIE because they would find new rigs to add to the default parameters when upgrading old data to the new interface.

  • Improve debug info for player controller/view target setups Add information about viewport size and aspect ratio.

  • Add screen-space framing option on the Aim-At camera action.

    • Adds a Target Framing property for where to frame the target on screen.

    • Use the new 2-bone IK function that takes into account an offset from the centre camera aim.

    • Improve the debug rendering a bit with extra information about the aiming.

    • Change the default lock-on tolerance to be a bit looser.

  • Remove GetTargetAngles and use proper projection/unprojection for all of the framing nodes' logic.

    • Make the dolly and panning nodes use projection/unprojection for computing how to recompose their shots.

    • Add more utility functions for projection/unprojection.

    • Make the projection/unprojection functions handle non-default aspect-ratio axis constraints.

    • Fix some issues in GetEffectiveFieldsOfView where it didn't correctly account for non-ideal aspect ratios.

    • Remove FCameraFramingMath which isn't used anymore.

  • Move the CameraPose-to-MinimalViewInfo code for easy re-use.

  • Add icons for Camera Rig Actor and Component.

  • Remove extra root node event API Reimplement the evaluation service's `OnRootCameraNodeEvent()` API in terms of the existing event that exists on the root node evaluator. This removes a bit of core API that wasn't needed.

  • Make the easing blend type a BlueprintType.

  • Update unit tests following changes to camera assets.

  • Fixes and improvements to the interface parameter panels.

    • Better default names for newly added parameters.

    • Support keyboard shortcuts for renaming and deleting parameters.

    • Add a button to delete selected parameters.

    • Properly refresh the list of parameters when undoing/redoing an add or delete.

  • Clean-up and improve handling of driven camera node parameters and multi-level prefabs.

    • Unify a bunch of code handling reflection-based node parameters vs custom node parameters (those obtained through the `ICustomCameraNodeParameterProvider` interface). Now there's the `FCameraNodeParameters` class that can build a list of available parameters on a camera node. This dramatically reduces the code in the Camera Rig builder class.

    • Fix some issues with multi-level parameter overriding, such as when an exposed parameter is re-exposed a level higher. Also, automatically flag connected prefab parameters as "overriden" on the prefab camera node to make sure those overrides are taken into account.

    • Rename some properties on custom parameter infos and interface parameter objects to be a bit clearer: "ParameterType" should be only for the parameter definitions, to specify if a parameter is "blendable" or "data". We should use "VariableType" for the type of variable to use in the variable table.

    • Simplify some of the parameter override helper code and remove unnecessary helper methods.

    • Add some unit tests for multi-level prefabs.

  • Add ways to parameterize post-process settings.

  • New "aim-at" camera action This action aims the current active camera rig instance towards a given target. It has options for keeping the lock on the target indefinitely until the action is stopped. The code for IK-aiming and other rotational corrections has been refactored so it can be used in the new action too.

  • New "lock user input" operation This operation locks user input for one frame.

  • Make value interpolators into constructable objects in Blueprints.

  • When a Boom Arm or Spline Orbit node doesn't have an input node, use a Driven Control Rotation node Before, these nodes were handling input themselves by querying the Control Rotation themselves. Now they use the seemingly better Driven Control Rotation logic. Also implement missing serialization of the boom arm length interpolator in the Boom Arm node.

  • New camera action service Camera actions are ways to execute operations on one or more running camera rig instances. They effectively "wrap" the root node evaluator for a camera rig, allowing arbitrary logic to be run before and after a camera rig evaluates. Camera actions also come with a few built-in options, such as the ability to clone themselves when a new camera rig activates, allowing a particular operation to persist over a long time.

  • Expose the blend type as a data pin on the easing blend node.

  • Make separate "getter" nodes for camera parameters, describe their connections in more general way.

    • Camera parameters were previously objects that doubled as their own node. This prevented driving two or more camera properties with the same parameter. This change removes the "node" aspects from camera parameters and adds a new "getter" node for that. The "getter" nodes point bac to the parameter they represent.

    • Previous data is gracefully upgraded for camera parameters that were present as nodes.

    • Since parameters may be connected to multiple pins, we can't determine their default value from that anymore, so the parameter has its own value now, a bit like variables in Blueprint. This changes a few things regarding the build process. A new customization class allows showing that default value in Details View for the user to set. Other parameter options (like "pre-blended") are removed from the list-view in the parameters panel: Parameters are now meant to be tweaked in the Details View.

    • Parameters can be added in transition graphs, for driving properties on blend nodes and such. A new base schema class provides support for this (a lot of its code is moved from the the camera node tree graph schema).

    • Actions for adding or auto-wiring parameters are changed accordingly (they now deal with the "getter" node mainly).

  • Make the search feature in camera editors based on the edited graphs and not the underlying object model Previously, searching through camera node or transition graphs was done based on the underlying object trees. Now, we more simply search the graphs that have been created out of these objects (thanks to UObjectTreeGraph). This makes it possible to get search results that are only indirectly related to the underlying data model, such as extra nodes and pins that show up in the editor.

  • No longer renders two debug infos when a GPC camera manager is running with a nested standalone GPC camera component Since the camera manager and the view target were both considered as the site for the "default" camera system, the camera debugger would end up drawing them on top of each other. Now we only consider the view target as default if the camera manager doesn't already run a camera system itself.

  • Activate and deactivate the output camera component along with its parent This fixes problems where a deactivated Gameplay Camera/Camera Rig component is still picked up by the engine when its owning actor is set as the view target, even though there's another active camera component on that actor.

  • Add option for freezing previous camera rigs when activating a new one.

  • Unify how Guids are generated for various assets.

  • Occlusion material node now supports skinned meshes and attached components.

  • Make sure components' parameter overrides are up-to-date with the referenced asset Update parameter overrides struct when starting evaluation, and on cook.

  • Add parameter GUIDs as tool-tips in the interface parameters panel.

  • Auto-rotate input node now supports going towards a zero rotation.

  • Boom arm node now supports additive rotation mode.

  • Improve how we apply parameter overrides from asset references Remove the need to keep the cached copy of the parameter overrides to detect changes: instead, just compare the new override values to the values found in the variable and data tables.

  • Add basic natvis support for the context data table.

  • Add easing blend node.

  • Make the boom arm and collision push node evaluators extensible.

  • Clean-up how components and player managers interact Simplify the camera component:

    • It now has an option to either run its own camera system ("standalone" mode, which is the default) or only run a camera evaluation context.

    • Remove some of the old code that attempted to handle a mix of both cases (such as with the non-immediate deactivation code) Simply the player camera manager:

    • Now anything that is set as the view target is run as a "blackbox", whether it's an arbitrary actor or vanilla camera actor or procedural camera (in which case it's better to use the aforementioned "standalone" mode).

    • To use fancier features such as blending or children directors, the procedural camera must be activated using dedicated new methods such as "Activate Gameplay Camera". Other clean-ups:

    • Move and improve on all the methods to activate/deactivate rigs and rig modifiers, and start/stop shakes.

  • Add Blueprint function for checking the validity of a shake instance ID.

  • Cleanup live-edit node listeners after a GC pass.

  • Make perlin noise use cubic splines by default This fixes undesirable "mini-pauses" in the middle of some curve segments when using a standard smooth-step interpolation.

  • Add more Blueprint methods to the components for managing persistent rigs and shakes.

  • Change how auto-build for PIE works to prevent packages from being modified at the wrong time.

    • Building a camera asset may change its data and dirty its package, but the previous method was doing when we were already inside the PIE world.

    • This change uses the same method as Blueprints, StateTrees, and so on, by using the BeginPIE delegate along with typed object iterators to gather objects to process just before PIE starts.

  • Add output return value pin to BP parameter setter node.

  • Add BP node function to get the owning rig.

• Network Prediction Plugin

  • Integrated time dilation feature to shrink input buffer size once network conditions improve.

  • Removed code related to physics integration that has been unsupported for a long time.

  • Added Iris replication support to the Network Prediction Plugin, while maintaining compatibility with non-Iris replication.

• Chaos Mover

  • Add optional server inputs for server side launch and other effects.

  • Stop applying angular velocity to target if the character should not remain upright and add option to never apply angular velocity to target in a falling mode.

  • Added some improvements for pushing into small, low objects.

• Game Input: Add haptic audio endpoint support via WASAPI and audio submix endpoints, just like the WinDualShock plugin.

• Add a new "Input Device Registry" (FInputDeviceRegistry) FInputDeviceRegistry is a thread safe registry to keep track of a FInputDeviceId to its name and type. This will make FInputDeviceScope obsolete. The registry is populated upon device connection and FInputDeviceId assignment, opposed to FInputDeviceScope's requirement of an actual input event call on the message handler being necessary.

• Adding MovementInterface meant to be used by various movement systems. By design it is very simplistic and helps with broad and common uses like gathering velocity, location and updated uobjects.

• Allowed conversation task nodes to choose branches in a specific order when advancing the conversation instead of always choosing a random branch. This makes it easier to set up progressive dialogue branches, e.g. a different branch based upon quest progress. Previously, each branch would need to have mutually exclusive conditions otherwise multiple branches would be possible and one would be randomly selected.

• In the Game Input plugin, make it possible to ignore or filter out devices from game input based on a VID/PID combo or their device family.

• Add a "preferred input API" setting to the engine. This will allow games to slowly roll out a change from an older input APIs like XInput to a more modern one like GameInput. The intent is that you could have a setting in your game, similar to a rendering setting for choosing which API to use, where players can enable/disable different input APIs to achieve the best compatibility for their setup. This has the added benefit of being able to "upgrade" a live project to use a newer input API with a fallback option via the config system.

• Spline Optimizations + Early out of SetClosed if it's already true. + Avoid re-constructing the TSet of normalized knot values in GetNearestAvailableKnotValue as this was being done repeatedly in GenerateDistanceKnotsForBezier. Reduces cost of GenerateDistanceKnotsForBezier by 90%. + Update FNewSpline::RebuildLegacyCurves to cache the attribute channels as these lookups were expensive. Also replace insertion sort of the rotation/scale points with a final sort at the end. + Add nullchecks when accessing scale/rotation attribute channels to prevent crashing when those channels are removed.

• Deprecate the Raw Input plugin in favor of the newer Game Input experimental plugin.

• Added support for dynamic (added at run-time) ability triggers to be used with abilities.

• Game Features: Made UGameFeatureData::GetDisallowedClasses() virtual so game project subclasses can prevent some Game Feature Action classes from being selectable.

• Converted Characters, Character Movement and dependent functionality to use a UObject representation of Movement Bases instead of UPrimitiveComponents. This opens up movement bases to non-actor objects such as FastGeoStreaming objects or Scenegraph objects.

  • ACharacter, UCharacterMovementComponent and other classes listed above have multiple examples of how to network and use this new struct, as well as examples of converting existing functions to use the new struct. See any function in the CharacterMovementComponent (such as UCharacterMovementComponent::RevertMove) as a good example of the new functionality.

  • ACharacter::OnRep_ReplicatedBasedMovement() shows a decent example of how to network and create this new struct from a UObject using MovementBaseUtility::GetMovementBaseDataFromPhysicsOwner.

  • FMovementBaseInterfaceData houses a UObject PhysicsObjectOwner and IPhysicsBodyOwnerInterface that implements necessary functions for basic movement base functionality.

  • FMovementBaseInterfaceData replaces UPrimitiveComponent as how code interacts with movement bases but a UPrimitiveComponent can be used to make a FMovementBaseInterfaceData easily as UPrimitiveComponent implements the IPhysicsBodyOwnerInterface interface and is a UObject so it is both the PhysicsObjectOwner and BodyInstanceOwner.

  • This change modified important classes/structs such as ACharacter, UCharacterMovementComponent, FBasedMovementInfo, FCharacterNetworkMoveData, FClientAdjustment and MovementBaseUtility with deprecation and fixup so they properly use new FMovementBaseInterfaceData struct. So any code extending the CharacterMovementComponent or code dealing with FBasedMovementInfo will likely need to be fixed up to support the new struct.

Bug Fix:

• Mover

  • Fix bug where skipping vertical anim root motion was not being respected in all montage cases.

  • Fixed inconsistent behavior during mode-changed events and the possibility of a queued mode getting ignored.

  • Fixed bug where sim proxy movement resulted in poor motion of any attached rigid bodies, such as ragdoll.

  • Fixed bug where activation of scheduled layered moves and instant effects would occur 1 frame late on variable-tick configurations.

  • Fix bug where a montage's RateScale was not respected during root motion layered moves.

  • Fixed issue with stale floor information causing teleportation-like behavior.

  • Disallow more than one active root motion montage layered move at a time.

  • Fixes crashes that can occur when compiling a MoverComponent BP while PIE is running with an instance of it.

  • Fixed sim proxy montage time drift that was causing divergence with root motion animation playback.

  • UMovementUtils::ComputeVelocity now limits velocity input to max speed properly.

  • Fixed issue where residual spring state persisted after interruption, such as during a root motion montage.

  • Fixed issue where sim frame counts in trajectory prediction were always starting from zero, and added optional start time/frame to the prediction params.

  • Fixed crash that could occur if there was a rollback before BeginPlay completed.

  • Fixed bug where an invalid up-direction would result in any gravity override being turned off.

  • Step Up/Over functions now track and return movement time so we can properly keep track of it in movement modes. This fixed an issue in walking transitioning to falling that launched the character.

  • Initializing some FollowPathMode data in mode Activate so we guaranteed run it on servers and clients. This fixes a bug where control points sometimes never get initialized in forward predicted movement.

  • Fixed crash when using User-Defined Structs in a Mover data collection when Iris networking is enabled.

  • Fixed crash that could occur when dragging and dropping an asset into an already-running PIE session.

  • Fixed crashes that could occur when editing properties of a MoverComponent at runtime through the editor Details panel.

  • Fixed bug where the Play Montage BP node would find the first mesh component instead of the primary visual component.

  • Adding read write lock when Queueing LayeredMoveInstances.

  • Fixed issues when trajectory prediction was queried before MoverComponent was finished initializing.

  • Fix UNavMoverComponent::GetFeetLocationBased nullptr MovementBase access and invalid supplied data causing occasional EPathFollowingResult::Blocked for AI agents due to bad samples.

  • Fixed up incorrect UE_REQUIRES arguments in GetMoverComponent and GetMoverComponentChecked functions in MovementModes.

  • Fixed bug where a tag cancellation request would cancel a layered move that was queued later during the same frame.

  • Fixed bug where continuous corrections could occur when transitioning from a skeletal mesh base with a valid bone to a static mesh.

  • Fixed bug where simulation events with timestamps close to each other could be processed out of order.

• Enhanced Input

  • Prevent triggers from re-firing after FlushPressedKeys while key is held.

  • Fix a long standing Enhanced Input issue around input triggers and modifiers not correctly maintaining their state when RebuildControlMappings is called.

    • Now when control mappings are rebuilt, if a key mapping already existed and its modifiers/triggers have not changed, each UInputTrigger and UInputModifier will call a "OnReinstanced" function (OnTriggerReinstanced and OnModifierReinstanced respectively).

    • This provides triggers and modifiers the chance to copy over any state that needs to be preserved across key mapping rebuilds. You can also implement these functions in custom Blueprint trigger or modifier classes by overriding the "Receive Reinstanced" functions.

    • This fixes bugs such as "Down" triggers having their input events re-fired every time the control mappings are rebuilt, even though you have not yet released the key.

    • This also fixes some issues with input modifiers which maintain state over time, like smoothing modifiers that want to keep track of the last used input value. This also fixes an issue with key mappings which _are_ actually new, and did not respect the bIgnoreAllPressedKeysUntilRelease flag. Now, new mappings will correctly be ignored if they are down when an IMC gets added and has a mapping to them.

  • Fix a bug where key mappings would not correctly be ignored if the input was just flushed (for example, by changing input modes between Game and UI for the player controller).

  • Fix mappings to AnyKey getting into a broken state when mouse scroll wheel up/down were used.

  • Enhanced Input: For boolean input actions mapped to touch Fkeys (FKey::IsTouch), the X,Y values of the keys will be the screen coordinate position. This means that a boolean input action will always evaluate to true, even after the touch has been released. To fix this, have Enhanced Input check the key state's bPressed value instead of the raw X,Y value in UEnhancedPlayerInput::PrepareInputDelegatesForEvaluation. This will ensure that touch FKey values have the expected trigger state flow and are calculated correctly in the IsActuated function of UInputTrigger.

• Mover Examples

  • Fixed crash that could occur if FollowSplineMode had a bad/missing spline actor during setup time.

  • Improving handling of orientation intent when not orienting to the movement direction.

• GAS

  • When marking abilities as garbage, also mark any SubObjects of those Abilities as Garbage. LyraGameplayAbilities can have SubObjects that must be MarkAsGarbage with their Outer.

  • Fix for GEComponents accessing other UObjects during PostInitProperties while AsyncLoading is enabled.

  • Using Generic Replication, the GameplayTagCountContainer could get stuck in a state where it constantly replicates a None tag if any of the tags were set to non-replicated.

• Cameras

  • Detail customizations for CineCameraComponent presets were not correctly checking IsEditable on the properties, and missing applying some new properties.

  • Fix rewind debugger crash when recording post-process settings with weighted blendables.

  • Fix missing pin on nodes in camera shake graphs.

  • Fix DPI scaling issue in debug renderer.

  • No longer asserts when (re)activating a Gameplay Camera component that is already active.

  • Fix issues with camera actions started on the same frame camera rigs are activated When a camera rig instance is pushed on the main blend stack on the same frame that a camera action is started, that action could be created on the previously active camera rig, resulting in incorrect behaviour as the action only affected the camera rig that was blending out. This change therefore starts actions in a "pending" state where we don't create the action evaluator until after the camera director has run. To make this possible, evaluation services have a new callback for evaluating between the camera director update and the root node update. Added new unit tests for camera actions.

  • More fixes for not modifying assets during load/build unless warranted.

    • The code that upgrades old Camera Asset parameters to the new interface needs to reproduce the old bug that even non-visible parameters were included :(.

    • Non-visible parameters don't have the CPF_Edit property flag, so also patch that when loading data in the version of the engine that didn't handle property flags in property bags.

  • Fix regression bug about camera node parameters being incorrectly built when they use a camera variable asset.

  • Make sure the "aim at" action uses the shorter rotation to accomplish its goal.

  • Fix assert sometimes firing after rebuilding a camera rig When a Camera Rig Component is selected in the level editor, it shows up in the Details View and the customization for the Camera Rig reference is active. When the referenced Camera Rig is rebuilt, that customization automatically updates the reference's parameters property bag. So when the component itself ends up receiving the build notification, the reference's parameters are up to date. This prevented the component from reinitializing the evaluation context, and could lead to asserts if new parameters were added, since those entries wouldn't exist in the variable or context data tables.

  • Fix missing code path for connecting to struct data properties.

  • Remove calls to Modify() from PostLoad()

  • Fix incorrect pragmas.

  • Fix assert on running a Camera Rig component This is a fallout of a previous change -- the generated Camera Asset in a Camera Rig component didn't have the correct allocation info anymore for initializing the evaluation context's variable and data tables.

  • Fix unity builds potentially leading to symbol redefinition.

  • Fix asset dirtying problems between camera rigs and camera assets The first problem is that camera rigs build all the allocation information they need, including the memory needed for their evaluator tree, and the entries they need in the variables/data tables.

    • This can easily mark a camera rig asset as modified, when:

      • (1) evaluator classes change (e.g. a new field is added) or

      • (2) when a referenced camera rig, such as a prefab rig, changes in a way that affects its own allocation info.

    • This ends up prompting the user to re-save assets that they haven't touched, with no obvious reason why. So the solution to this is easy: only build allocation info during cooking. In non-cooked builds, we just allocate things as we go, which is less performant, but much better for the user.

    • The second problem is that camera assets were automatically gathering all the exposed parameters from all their referenced camera rigs, and using that as their own exposed parameters. This was simple and functional at first, but it also created the same problem: the camera asset would get flagged as modified when any referenced camera rig had new/changed/deleted parameters. This again prompted the user to re-save the camera asset for no good reason.

    • In addition to that, as camera assets grew in scope, they could start getting a lot of parameters that the user didn't necessarily want. Solving this problem requires a new workflow: the camera asset editor now has an "Interface Parameters" panel, similar to the camera rig editor. It lets the user add/remove parameters on the camera asset itself, and specify how each of these parameters binds to which camera rig's parameter. It effectively removes the automatic step of gathering all referenced camera rigs' parameters, and replaces it by a manual step where the user can pick and choose which parameters to expose on the camera asset. This way, modifying a referenced camera rig doesn't modify the camera asset: the user has to explicitly modify the camera asset if they want its interface to change. Other notes about this change:

      • All the builder classes and methods now pass around a base "build context", which contains information about whether we're cooking or not.

      • Camera assets are upgraded on build or open to get a default list of interface parameters that reproduces what was automatically built before.

      • When initializing a new camera rig instance, we now ensure that the variable/data tables have all the entries needed. This makes uncooked builds work by lazily allocated memory when we don't have the allocation info.

      • The camera director's GatherUsageRigInfo now does extra stuff out of the box, such as looking into the proxy redirect table, and removing unwanted things from the output.

      • The code that converts a variable/data entry info a graph editor pin type has been moved into a common place for reuse.

  • Move easing blend node to the correct directory.

  • Fix some edge cases with the context data table.

    • Prevent access to some template functions for enum types when it can return pointers to incorrect underlying int size.

    • Add some extra checks to array setters.

  • Continue recording debug info even when a camera system doesn't have any evaluation context active.

  • Fix bugs related to enums in the data table.

    • Store enums with an int32 for handling large flags enums.

    • Fix a bug where we have to convert the value (not the pointer) of a data table entry in the case of enums, which may have different backing types.

    • Also fix incorrect data traits for strings.

  • Fix incorrect FOV when using a vanilla camera component or actor as the view target inside a GPC camera manager When setting the FOV or focal length on a camera pose, we always need to invalidate the other so that both aren't defined at the same time.

  • Ensure we continue handling collision results events when we don't hit anything This fixes a regression where absence of collision would lack updating the damper to return back to the "rest" position.

  • Fixup default parameters on load as a workaround for a bug in FInstancedPropertyBags.

  • Fix possible crash when clearing the camera asset or camera rig asset on a component.

  • Protect panning framing node from introducing NaN rotations.

  • Fix some problems with the screen-space framing nodes.

    • No longer stops reframing once the target is in the dead-zone, keep following it if it's still moving.

    • Modulate the reframing based on the disengagement time to get a semi-random rest position inside the dead-zone.

  • Get rid of the debug info if we don't need it anymore This fixes a bug where editor visualization stops working if the user activated debug display once.

  • No longer offers to create graph nodes when going "up-stream".

    • Also, it caused an undo bug since, after creating a node of the same type, the schema was trying to connect that to the dragged pin (the "self" pin on the first node). Which isn't possible. So it would fail, which would cancel the connection transaction, which would cancel the creation transaction. But the creation happened, so it made the creation of the (useless) node non-undoable. Now we just don't offer to create it anymore.

    • The ObjectTreeGraph model is mostly meant to go from "left to right", i.e. from an object to its properties to the objects connected to these properties. Dragging the "self" pin to the left only offered to create the exact same node type because that's the only node type compatible with itself generally (unless there are subclasses in existence). So it's mostly useless.

  • Fix how the output camera component is created.

  • Fix possibly incorrect evaluation layer when starting a modifier rig.

  • Fix logging formatting.

  • Fix missing sub-object destruction in gameplay camera component.

  • Look for rigs and rig proxies used by directors more than one package away This fixes the issue of, say, a Blueprint director using some data table or chooser asset for selecting rigs, which meant that the "family shortcuts" and other things using the UsageInfo API had incomplete info.

  • Fix crash when opening the Blueprint palette The palette creates "template nodes" that aren't actually fully initialized, and are prevented from loading any data.

  • Fix double-negation and incorrect comment.

  • Fix GetActiveCameraRigEvaluationInfo returning the wrong information when rigs are blending.

  • Fix camera variable overrides not working in PIE In editor/PIE builds, the camera asset's AllocationInfo (variable and context data tables) is only populated at cook time, so it is empty when running in-editor. This caused GameplayCameras component overrides to silently fall back to default values. When AllocationInfo is empty, we now gather it transiently from the camera rigs at runtime, mirroring what CameraAssetBuilder does during cooking. Cooked builds are unaffected and continue to use the pre-computed AllocationInfo as before.

• Chaos Mover

  • Fixed the calculation of inverse inertia when applying jump reaction impulse. This ensures the correct impulse is applied when jumping from dynamic objects.

  • Fixed bug in pathed movement mode where looping could behave incorrectly.

  • Updated the ground check query sweep in falling mode to account for the updated velocity. This prevents fast moving characters falling through the ground.

• CMC: Prevent unexpected upwards velocity boost when jumping/falling upwards into an acute angle corner of steep walls.

• Level Streaming Persistence plugin: Fixed crash when persisting properties on a map placed actor that got destroyed but is part of a reused level instance.

• Fix an operator discrepancy in UEnhancedPlayerInput::AddMapping. Use the.Equals function instead of operator== on FEnhancedActionKeyMapping when adding mapping to enhanced input.

• Fix crashes when game feature plugins caused a garbage collection at a bad time, it now always performs the garbage collection at the end of the frame.

• Fix issue where trying to unregister an asset from a temporarily-unregistered DataRegistry would fail, causing GC leaks when the data registry is reinitialized later.

• Upon device connection, populate data in the UInputDeviceSubsystem about the given device if a valid FInputDeviceScope is available. This makes it a bit easier for gameplay code to query the input device subsystem when connection events happen instead of needing to wait for the user to actually press an input for it to be populated.

• Circular buffer: Reduced checked capacity limit that was too high.

• Multi Server: FPredictionKeys should always send full data when communicating with a proxy.

• Fixed assertion in FVisualLogger::CleanupRedirects.

• Fixed bug that would propagate stale CurrentEventData to future ability calls that received a nullptr CurrentEventData during activation.

• Fix bug where the tick manager could get deadlocked in EndPhysics because it failed to properly flush the manual dispatches.

• Fix issue where AsyncSaveGameToSlotForLocalPlayer would ensure if called twice in a row. It now sets the LastSuccessfulSaveRequest to the request that actually completed instead of the last requested.

• Fix ScalableFloats to correctly reset cached curve when serializing or copying. This fixes issues when used in inherited Blueprints.

• Fix several issues with C++ defined gameplay tags when a game feature dll is loaded after startup. Fast tag replication cannot support this case but Dynamic tag replication should now work correctly with late dll loads.

Deprecated:

• Improve comments for tick functions to correctly indicate thread safety, and deprecate GetLastTickGameTime because it was confusing.

• Enhanced Input: Deprecate the combo trigger. This trigger type is unreliable and can cause mapping contexts to be corrupted in the editor.

Mass

New:

• Mass Trace

  • Add missing trace events for archetype creation and entity moves during archetype splitting in MassEntity Introduce a batch UE_TRACE_MASS_ENTITIES_MOVED macro to trace multiple entity handles in a single call.

  • Extract MassInsights trace provider and analyzer to new MassDeveloper runtime module. Move FMassTraceProvider, FMassTraceAnalyzer, IMassTraceProvider, IEditableMassTraceProvider, and all supporting data types (FFragmentInfo, FArchetypeInfo, FEntityEventRecord, FRegion, FRegionLane, etc.) from MassInsightsAnalysis plugin to Engine/Source/Runtime/Mass/MassDeveloper under the UE::Mass::Trace namespace. Port all MassInsightsUI consumers to the new types. Simplify module entry point via SetupMassTraceAnalysis() factory function.

  • Add Sparse, ConstShared, and SparseTag fragment types to MassInsights and MassEntity tracing Include shared and sparse elements in archetype registration trace output Check derived types before base types in fragment type classification to avoid incorrect matches.

• Mass Commands

  • Extend fragment instance and build commands to support mixed element types in a single entity move New commands:

    • Add FMassCommandAddElementsWithSharedFragments<TTypes...> for composition-only changes + shared fragment values in one move.

    • Add FMassCommandAddFragmentInstancesWithSharedFragments<TShared, T...> for fragment values + shared values in one move.

    • Add convenience methods on FMassCommandBuffer: AddElementsWithSharedFragments, AddFragmentInstancesWithSharedFragments Extend existing commands to accept tags and sparse types:

    • FMassCommandAddFragmentInstances<T...> now accepts FMassTag, FMassSparseTag, FMassSparseFragment alongside FMassFragment.

    • FMassCommandBuildEntity<T...> same mixed-type support.

    • FMassCommandBuildEntityWithSharedFragments<TShared, T...> same mixed-type support.

    • Tags included in composition, excluded from value payload (GetAsNonTagGenericMultiArray).

    • Sparse types handled in-place via BatchAddSparseElementToEntities before composition changes EntityManager API additions:

    • BatchChangeCompositionForEntities overload with FMassArchetypeSharedFragmentValues.

    • BatchAddFragmentInstancesForEntities overloads with FMassTagBitSet and/or FMassArchetypeSharedFragmentValues.

  • Unify Add/Remove commands with FMassCommandAddElements and FMassCommandRemoveElements.

    • Add FMassCommandAddElements<TTypes...> (PushCommand batching) and FMassCommandAddElementList (PushUniqueCommand) for adding any mix of fragments, tags, and sparse elements in a single entity move.

    • Add AddElements convenience methods on FMassCommandBuffer (templated and runtime).

    • Redirect AddFragment, AddTag convenience methods to FMassCommandAddElements.

    • Deprecate FMassCommandAddFragmentsInternal and FMassCommandAddTagsInternal.

    • Add sparse element support to FMassCommandAddFragmentsInternal and FMassCommandAddTagsInternal by splitting sparse types to BatchAddSparseElementToEntities.

    • Add check in BatchChangeCompositionForEntities rejecting shared/chunk/sparse on Add side.

    • Add chunk fragment rejection in BatchAddElementToEntities and AddElementToEntity.

    • Fix CheckBreakpoints signature on AddElements and RemoveElements to match composition-only usage (entity-only, no fragment instances).

    • Add unit tests for chunk/shared/sparse Add-side gaps.

  • Add bitset-level and runtime type validation for Mass element composition.

    • Shadow GetTypeBitSet<T>() in DECLARE_NEWTYPEBITSET to static_assert that T matches the expected element subtype, not just FMassElement (root cause fix for typed bitset accepting wrong element types).

    • Add testableCheckf guards in BatchChangeCompositionForEntities to validate that ElementsToAdd and ElementsToRemove contain only tags and fragments, catching misuse before it reaches InitializeWithSimilar.

• Extend BatchRemoveElement to support shared fragments and add unit tests.

  • Extend IsElement() to accept shared and const shared fragment types.

  • Extend BatchRemoveElementFromEntities and RemoveElementFromEntity to dispatch shared and const shared fragment removal via new InternalBatchRemoveSharedFragmentsFromEntities.

  • Add testableCheckf to Add element APIs rejecting shared fragments with clear message.

  • Add unit tests for FMassCommandAddElement/FMassCommandRemoveElement covering tags, fragments, shared fragments, const shared fragments, mixed types, and negative cases.

• Additional archetype information (list of elements, list of entities) retrieval.

• Added a single call to check fragments or tags or in an archetype.

• Mass trait validation errors now highlight the trait net mode to help pinpoint the issue.

• Queries can now return a topology hash for their archetypes.

• Added UMassRepresentationActorManagement::IsActorReadyForRepresentation, a virtual hook (default returns true) used to wait for actor readiness before switching off ISM. While the hook returns false the processor keeps the ISM/SkinnedMesh visible and the spawned actor disabled; game-side subclasses can override it to gate the transition on async asset streaming. The wait is bounded by the ai.massrepresentation.MaxActorVisualReadinessWaitFrames cvar (default 255), after which the actor is force-enabled and a warning is logged.

• Added trajectory generation and spring movement code to MassGameplay (experimental) Mass Traits:

  • U Spring Movement Trait: Adds spring-damped movement.

  • U Trajectory Trait: Adds trajectory generation.

  • U Trajectory Movement Trait: Overrides movement to follow trajectory.

• Removed MassEntity's dependency on AITestSuite. The testable-ensure mechanism (global counter + 3 macros) was moved into MassCore itself, so it no longer pulls in AIModule and GameplayTasks through a Developer module.

• Mass Debugger: Added SparseElement bitset to the archetype details Note that the information exposed is the aggregated info from all chunks; it doesn't mean that all entities have the element.

• Modified UE::Mass::Utils::CreateEntityCollections to handle the common single-entity input case, and to perform better when multiple entities of the same archetype are processed.

• API Change: Made the FMassArchetypeCompositionDescriptor(const FMassElementBitSetand) constructor non-explicit, in preparation for the near-future removal of FMassArchetypeCompositionDescriptor.

• Mass Gameplay Debug: Made AssignDebugVisProcessor editor only to prevent useless registrations on non-editor builds Also made sure it is properly setup for registration when WITH_MASSGAMEPLAY_DEBUG i s0.

• Mass Entity: Add observer support for shared fragments and swaptag.

• Added the missing FMassCommandRemoveElement command.

• API Change: Renamed FMassEntityManager::AddElementToEntities and RemoveElementFromEntities to BatchAddElementToEntities and BatchRemoveElementFromEntities respectively, for consistency with the rest of the API.

• Extended the MassEntityManager and Archetype API to support the use of struct views.

• Added a flag to EntityBuilder to force-committing always through Mass commands. Added the mass.EntityBuilder.ForceDeferredCommit cvar to set this behavior project-wide.

• Added a way to configure MassEntityTraits to be valid for a specific target configuration (Standalone, Client, Server, etc).

• Move Actors for entities spawned by AMassSpawner into an Outliner folder that matches the name of the spawner.

• Added Sparse Elements, along with support in queries, commands, and entity builder. Sparse Elements are Mass elements (tags and fragments) that can be added to entities without causing them to change archetypes — they are not part of an archetype's composition and are handled individually per entity.

• Renamed GetOrSpawnActorFromTemplate to GetOrRequestSpawnActorFromTemplate to reflect that the function requests a spawn rather than spawning synchronously. Declaration, definition, and all callers were updated.

• Exposed mass processing phase tick functions in public API to allow for setup of tick dependencies.

• TStructTypeBitSet changes to support "single element bitsets":

  • Alternative implementations of bitwise operators.

  • Default to 8 elements as bitarray's initial allocation size.

  • Modified some functions' signatures to support more flexibility.

Bug Fix:

• Fixed matches queries with Any fragments and tags to archetypes with only one or the other.

• Mass entity world subsystem now flushes remaining commands on deinitialization. This is required to cleanup any elements registered to other subsystems or rendering scene.

• Improvement: [Mass Representation] Switched two manually calculated bDoKeepActorExtraFrame branches to use the new UE::Mass::Representation::ShouldKeepActorExtraFrame helper. Bug Fix: [Mass Representation] Fixed the issue where the original conditions weren't respecting the value of FMassRepresentationParameters.bKeepActorExtraFrame.

• Mass Debugger fix: Struct redirects are now applied when pasting query JSON, mirroring the pattern in FInstancedStruct::ImportTextItem.

• Fixed an overzealous check in UMassAgentComponent::PausePuppet that crashed the function when called on a non-puppet. Switched the check to an ensure.

• Fixed: The Mass debugger running with an invalid entity.

• Fixed an issue in UMassSpawnerSubsystem::DoSpawning's BatchSetEntityFragmentValues when called in a loop with a single CreationContext — by iteration N the context included archetypes from prior spawns with different fragments. The call now builds a fresh local collection from just the current call's spawned entities.

• Fixed infinite recursion in FMassEntityConfig::FindTrait when the parent config chain contains a cycle.

• Fixed a MassAgentComponent assert when Iris destroys a puppet in the PuppetPendingReplication state. UnregisterAgentComponent previously had no handler for this state, so when Iris destroyed a replicated actor before its NetID replicated (e.g. on relevancy change) the component was stuck with no entity handle and no NetID. Added PuppetReplicationAborted() to cleanly bail out to None.

• Mass Debugger: Fixed wrong hierarchy representation of unnamed archetypes in MassDebugger by adding a composition hash identifier for unnamed archetypes and filtering out the None entry from debug names.

• Fixed `FMassCommandAddFragmentInstances` ignoring its `OperationType` parameter. The constructor accepted the argument but its initializer list hardcoded EMassCommandOperationType::Set, causing FMassCommandBuildEntity (which passes Create) to sort as Set during command buffer flush and hit a checkf on `entity state == Reserved`.

• Add stale model check to entity list refresh guard condition in Mass Entity Debugger.

• Fixed warning messages regarding undeclared subsystem access via FMassSubsystemAccess.

• Allow multiple registration of types with Mass, which avoids an ensure when using Mass from Game Feature Plugins.

• Removing CDOs from Mass settings on modules' unload.

• Fixed an off-by-one in CacheSubsystem where Subsystems.AddZeroed computed the wrong resize delta (Num() - SystemIndex instead of SystemIndex - Num()). The array is pre-sized in the constructor so this had not blown up in practice.

• World Condition: Fixed case where world condition queries would not be properly linked when embedded in a struct.

• Made naming spawned actors with the entity's GUID (when available) optional, and changed the default to false, since the previous behavior could cause unexpected issues.

• Fix for exporting struct array properties as json.

• AI Controller: We now end all tasks owned by the controller before calling OnUnPossess on the base class since those tasks might require access to the pawn's associated controller to exit properly.

Networking

New:

• Iris

  • Allow users to subclass UNetObjectPrioritizer easily.

  • Allow options to be passed to UE_NET_IMPLEMENT_NAMED_STRUCT_LASTRESORT_NETSERIALIZER_INFO and UE_NET_IMPLEMENT_NAMED_STRUCT_LASTRESORT_NETSERIALIZER_AND_REGISTRY_DELEGATES. Current options are to set the max quantized size, exclude from default state hash and custom fragment registration.

  • Added FInstancedStructNetSerializer delta serialization support.

  • Added the LogIrisCreationFlow log category to trace server-to-client root object creation timing across key Iris replication events, making it easier to correlate server and client logs and measure end-to-end object initialisation latency.

  • Fixing NetTrace to work with TailBuffer.

    • When active, the TailBuffer is constantly caching trace packets for the duration of a session. This means we need to ensure that each NameId is unique for the whole session, and also included in Important events to make sure there's no missing data.

    • It also means we may see multiple ConnectionCreated events with the same ConnectionId, as Traces aren't started/stopped in the same way when outputting a TailBuffer, so in the NetTraceAnalyzer we only update the ConnectionState the first time.

    • ResetLifetimeConditionDebugNames and OnResetPersistentNetDebugNames removed from the API as they are no longer required and would break the Trace Tail Buffer Fixing NetTrace to work with TailBuffer by keeping DebugNameIds consistent.

    • ResetLifetimeConditionDebugNames and OnResetPersistentNetDebugNames removed from Iris Net Trace API as they cause broken traces if Trace Tail Buffer is in use.

  • Added optional parameter to control if a subobjects child subobjects replicate before or after their parent.

  • ActorComponents still defaults to replicate their SubObjects before the components to not cause any unexpected divergences.

  • Clarified documentation.

  • Deprecated ESubObjectInsertionOrder::ReplicateWith in favour of explicitly specifying root and parent when adding a subobject.

  • Fixed bug where using ESubObjectInsertionOrder::InsertAtStart would shift conditionals around and apply them to the wrong subobject.

  • Added ensure if reliable attachementqueue is overcommited.

  • Implemented support to allow start and StopReplication being called multiple times for static objects including support for flush.

  • Refactored FlushLogic to be more robust and behaves closer to normal destroy.

  • Fixes issue where the same static NetRefHandle/Object could end up being replicated as multiple NetObjects/Channels causing bugs on client.

  • Fixed case where flush was not propagated properly to new connections.

  • Fix for ObjectPoller using the parent net stats rather than the passed in child net stats. Fixed a small chance of incorrect stats being generated when using NetStats with Multithreaded Iris Polling.

  • Replicated objects with creation links to other objects will replicate after creation dependencies before they replicate to reduce reordering on clients.

  • Implemented debug write pass for ReplicationWriter that writes NetObjects marked as debugobjects using separate packets not counting against bandwidth limit.

  • Added API for marking an object as a DebugObject.

  • Added API for allowing DataStreams to write DebugData that does not count against bandwidth limits.

  • Add a PreferredReplicationSystem setting to FIrisNetDriverConfig that can override the net.Iris.UseIrisReplication cvar for specific NetDriverDefinitions.

• Multi Server

  • Adding OnAllServersConnectedEvent as a potential Event to listen to.

  • LaunchMultiServer now supports -BotCount=XX which allows you to specify an overall number of bots which works in both -client=proxy and -client=direct mode.

• Iris Parallelization

  • Added API for network HandlerComponents to indicate support for being run in parallel. Enabled NET_ANALYTICS_MULTITHREADING so that OodleNetworkAnalytics can run in parallel Network HandlerComponents can indicate support for running in parallel per-connection. Enabled NET_ANALYTICS_MULTITHREADING by default.

  • Added API for network HandlerComponents to indicate support for being run in parallel. Enabled NET_ANALYTICS_MULTITHREADING so that OodleNetworkAnalytics can run in parallel Network HandlerComponents can indicate support for running in parallel per-connection. Enabled NET_ANALYTICS_MULTITHREADING by default.

  • Adding thread safety to NetworkMetricsDatabase and the related stats in NetDriver Added thread safety to NetworkMetricsDatabase and the related stats in NetDriver.

  • Make Net Tracing existing objects and object creation threadsafe. Added a SharedNewObjects list to temporarily store newly created objects in parallel net connection tick and then merge them with the full list after NetConnection Tick has completed. Net Tracing for object creation has been made thread safe for Iris Parallelization.

  • Make Net Tracing existing objects and object creation threadsafe. Added a SharedNewObjects list to temporarily store newly created objects in parallel net connection tick and then merge them with the full list after NetConnection Tick has completed. Net Tracing for object creation has been made thread safe for Iris Parallelization.

  • Added thread safety functionality to DeltaCompressionBaselineManager. Added FScopedBaselineAccess which guards parallel access to the BaselineManager, which is used in the ReplicationWriter in preparation for running it in parallel. Also renamed GetIsInParallelPhase to IsInParallelPhase to align with Iris Beta naming conventions. Added thread safety to DeltaCompressionBaselineManager.

  • Added thread safety to NetBlob, NetTokenStore, NameTokenStore, StringTokenStore and StructNetTokenDataStore

    • Added ExcludeParallelIrisSupport to TargetRules.cs so that licensees can remove these mutexes if they intend to run the server in single threaded and want a few nanoseconds of perf back.

    • Can be removed from compilation using ExcludeParallelIrisSupport.

    • Added UE_SUPPORT_PARALLEL_IRIS define which includes multithreading logic only on Server and Editor builds by default. Client only builds do not need the mutexes included as they will not run the replication logic in parallel.

  • NetConnection::Tick can be run in parallel on the server by setting net.iris.AllowParallelNetTick to true. UChannels can indicate support for parallelism in SupportsParallelTick Implemented thread safety for ObjectReferenceCache Iris replication supports parallel NetConnection Tick to run the write phase across multiple threads.

• Improved connection startup latency for numeric IPv4 addresses by sending the initial handshake packet in the same frame instead of waiting for the next-frame async resolution path. The net.NumericIPSyncResolve CVar can be used to disable synchronous resolution and restore the previous behavior.

• Added experimental NetworkServiceDiscovery plugin providing Windows/Mac/iOS/Android mDNS/Bonjour service announcement and discovery.

• Added a runtime CVar, HTTP.Curl.MaxHostConnections, to control libcurl's per-host HTTP connection limit and allow the concurrent request limit to be modified on demand.

• Add FScopedNetEmulationOverride class for easy, temporary network emulation overrides in test cases.

• FNetBitArray's ForAllSetBitsInRange is now handling invalid StartBit and EndBit parameters more gracefully.

• Net: Bumped default ServerDesiredSocketReceiveBufferBytes and ClientDesiredSocketReceiveBufferBytes to 262144 bytes to avoid dropping data if user does not override settings.

Bug Fix:

• Iris

  • Output the entire default state of replication state descriptors when encountering protocol mismatch errors.

  • Fix issue with destroyed object with destruction info being mistaken for a destruction info. Allow destroyed object with destruction info to be replicated if it needs flushing for example due to a reliable RPC being called the same frame it's added for replication.

  • Fixed memory leak in PolymorphicStructNetSerializer.

  • PlayerStates are now prioritized using the NetObjectCountLimiter with the PlayerStateCountLimiterConfig by default and as intended.

  • Fixed replication issues when connecting a standalone client to a PIE server.

  • Fixed internal leaks of subobjects being torned off.

  • Fixed filtering hysteresis bugs for late joining connections.

  • No longer stores instanced struct type in the InstancedStructNetSerializer default state as the client is not being able to resolve the type.

  • Fixed rare crash when enabling parallel polling.

  • Fix issue with newly created dependent object entering hysteresis despite parent being filtered out already.

  • Fixed issue with dependent objects potentially getting replicated when they shouldn't and vice versa.

  • Fixed bug where new objects assigned to a previously used internal index could end up not being properly polled on empty servers.

  • Fixed issue where out of scope objects being created and destroyed the same frame requiring flush would be destroyed using the wrong code path.

  • Only call SetActorIsPendingPostNetInit for actors that are expected to call PostNetInit.

  • Fixed issue where a static actor would skip their call to BeginPlay if they are in pending dispatch list and BeginPlay was issues on world triggered from OnRep of another actor.

  • Fixed issue with ObjectPoller not force polling ObjectReferences for pushbased fragments in mixed protocols after GC.

  • Fixed scheduling of dependent objects to not be reversed if spilling over to next packet.

  • Fixed bug where unicast rpcs did not respect RPCSendPolicy.

  • Fixed bug where replicated objects overcomiiting reliable attachment send queue was not properly marked dirty when queue could accept send more data.

  • Addressed issues with PacketNotification getting stuck in deadlock if both ends overshoots ack sequence history.

• Multi Server: Multi-Server Proxy uses GetLocalRole rather than GetRemoteRole as we are executing in the context of a Client (GetLocalRole is what the Server assigned us and GetRemoteRole is always ROLE_Authority).

• Corrected inconsistent initial conditionals in void AActor::GetReplicatedCustomConditionState() reversed compared to what is later set in AActor::PreReplication.

• Fix for DemoNetDriver crashes due to accessing memory in destroyed actors.

• Fix for issue where replayout did not respect net.ReplicateCustomDeltaPropertiesInRepIndexOrder and always replicated CustomDeltaProperties in RepIndexOrder.

• Fix StaticMeshActor instances not replicating when setting are applied on the instance instead of the Blueprint asset.

Learning Resources

Sample Content

New:

• Enabled HDR display support and added HDR display settings to Lyra.

Level Design and Art Tools

New:

• Hide RayTracing, Navigation, LOD, HLOD categories from SplineComponent : The spline component inherits them from the primitive component but is not renderable or navigable itself.

Bug Fix:

• Preventive fix for water brush against OnLevelAdded/Removed callbacks that can get called while the actor is unreachable.

• Fix GetDynamicWaterInfoCenter output Fix missing implementation of GetDynamicWaterInfoBounds.

• Fixed edit condition for water nav area class.

Geometry Core

New:

• Extended the FSubdividePoly Dynamic Mesh OpenSubdiv wrapper to interpolate all standard mesh attributes. Now e.g. UVs, skin weights, colors, etc will be interpolated when using Catmull-Clark or Loop subdivision in modeling tools or Geometry Script.

• General attribute support for FMeshSimplification.

• Generalize SkinWeightBinding operation to support 'constrained' binding, where vertices can only bind to a known subset of bones.

• Added a point-triangle distances connection method to vertex connected components, to help optionally join nearly-connected islands when computing mesh islands.

• Added vertex-based region of interest update paths to DynamicMeshComponent, matching the Triangle ROI paths + exposed these update paths to UPreviewMesh also.

• Added option for sparse point octree ParallelRangeQuery to also use a custom TFunctionRef to filter which bounds are relevant to the query.

• Added vertex and triangle selection versions of FDynamicMesh3's bounding box compute method (with similar logic to compute in parallel chunks).

• Added option for dynamic mesh overlay's per-vertex build to make the elements exactly 1:1 with vertices, so caller doesn't need to worry about the vertex to element ID mapping.

• The dynamic mesh's attribute set generic attribute accessor now returns nullptr if the attribute is not found, rather than failing a check(), to match how most of the other accessors work when requesting an attrib that doesn't exist.

• We now fill colors from hole boundaries in most hole fill operations (except smooth hole fill).

• Made DDC cache put responses return the record/value that the cache contains This can be used to detect conflicts between new and existing data, when not overwriting existing data.

• Added medial skeleton → hierarchical / animation skeleton conversion via minimum spanning tree.

• Added medial-axis sampling/skeletonization to GeometryAlgorithms.

• Added a method for VertexConnectedComponents to merge only the close vertices that pass some other filter, so e.g. one can only do this merge step for boundary vertices (which can be much faster than doing it for all vertices, and also can avoid connecting some intentionally-separated-but-nearby vertices) Added a thread-safe method for getting the cluster ID of vertex-connected components.

• Added a MeshVertexNormals method that can account for implicit welding -- i.e. a known mapping of some vertices to common weld vertices.

• Added a Sort() method to FIndex3i, to change the indices to a sorted order (ala the one already on FIndex2i).

• Improved the dynamic mesh simplification algorithm to be smarter about what edges can collapse. Added an edge constraint tolerance distance to optionally limit how far constrained edges can move during simplification.

• Added mult-label version of mesh iso curves cutting, via adapters to support arbitrary mesh types.

• Geometry Script and Modeling Mode mesh to convex hull nodes and tools now have a geometric tolerance for hull simplification, to allow simplification below the target triangle count when it will not introduce more error above the geometric tolerance threshold.

• AABB tree now supports meshes with FVector3f vertex storage.

• Added optional regularization to the QEM simplifier.

• Added optional scaling functions for the QEM simplifier metrics (quadric error, target length, and geometry error).

• F Sparse Dynamic Point Octree3: Export FindKClosestPoints function.

Bug Fix:

• Fixed a crash that could occur due to an edge case in the AABB Tree building logic.

• Fixed performance issue with MeshSelfUnion on meshes with many open boundaries by using pointhashgrid to filter potential edge matches in self union by midpoint. Also now check for edge vertex position matches in either ordering.

• Fixed issues with sparse dynamic point octree.

  • Fixed queries hanging on very large query bounds (by refactoring IterateRootsInRadius's logic to clamp query ranges and fall back to all-root iterations into a general root iteration helper)

  • Fixed points very near cell bounds crashing on insert due to floating point error making CellContains() not agreeing with the cell assignment. Now CellContains directly uses the cell assignment logic. Fixed issue w/ octree range iteration methods where we could potentially overflow the large-range test by casting to double too late.

• Fixed minimal hole filler accidentally passing the input mesh by value to the CheckIfEdgeFlipCreatesFlip helper function.

• Fixed crash in hole fill op where it could use reference a triangle with unset UVs.

• Improved edge collapse parameter interpolation for dynamic mesh's mesh simplification method.

• Fixed DynamicMesh CompactCopy checking the wrong mesh's attribute set for compactness. Fixed const correctness of IsCompact on attribute set.

• Fixed mesh simplifier's bad placement of boundary vertices (e.g. rounding off corners) -- it now considers error when picking boundary vertex position instead of always just picking the midpoint.

• Fixed the FModuloIterator struct ignoring StartIndex.

Deprecated:

• Deprecated the version of SplitMeshes that takes a TArray<FDynamicMesh3>, to move code away from unsafe usage of FDynamicMesh3/TArray.

Geometry Script

New:

• Added more material management to the copy mesh to static mesh / copy mesh to skeletal mesh options.

  • Optionally use New Materials to only set materials on the currently updated LOD.

  • Add option to clean material IDs, so invalid material IDs will be set to reference a valid material instead.

• Default Mesh Simplify settings now apply a small regularization weight.

• Added regularization controls to the geometry script simplification options.

• Added more methods for managing weight maps.

• Added geometry script support for driving simplification error tolerance or edge lengths via weight maps.

• Add weight map support to Remesh node.

• Added a Perlin Noise method that computes noise scale from positions.