Movie Render Graph (MRG) provides you with a node-based system to manage render settings while creating high-quality image sequences and movie renders with Movie Render Queue (MRQ). These graphs can be as simple or complex as necessary to address the needs of both small and large teams.

These graphs can be set up to render a single shot or designed to scale out across complex multi-shot workflows. These graphs can be modified and saved as reusable assets, introducing greater flexibility to production pipelines.

The Legacy preset system of MRQ can be used interchangeably with the new MRG. For more information about MRQ, see the Move Render Queue documentation:

Prerequisites

• It is recommended that you have a familiarity with MRQ and the MRQ Render Settings before using MRG.

• You have a project with a Level Sequence to render. If you do not have a project with a Level Sequence you can render, you can use the Main_Seq Level Sequence in the Meerkat Demo as a sample.

• Enable the Movie Render Queue Plugin. Navigate in the Menu Bar to Edit > Plugins and locate the Movie Render Queue plugin in the Rendering section, or by using the Search Bar. Enable the plugin and restart the editor.

Project Alpha Channel Support

After enabling the Plugin, it is generally recommended to set the Enable alpha channel support in post-processing (experimental) property to the Linear color space only option. MRQ and MRG will work with any option that is not Disabled, however, when using MRG if this property is set to the Disabled for Render Layers option, the render will not include an alpha channel in the output images when the visibility and holdout modifier parameters are used. You can access this property by navigating in the Menu Bar to Edit > Projects Settings, then navigating to the Rendering section.

Opening the Movie Render Graph

The Movie Render Graph is accessible through the Movie Render Queue, which can be opened in Unreal Engine’s Menu Bar, navigate to Window > Cinematics > Movie Render Queue. You can also access Movie Render Queue in the Sequencer tab, using the ellipses next to the Render Movie button to expand the Render Movie Options. Select the Movie Render Queue option, then click the Render Movie button.

This will open the Movie Render Queue window.

Expand the arrow in the Settings column and select Replace with Graph (Experimental).

Expand the arrow again and select New Graph.

Name and save the graph in the Save Asset As window. A Movie Render Graph Config asset will now be shown in the Movie Render Queue Settings column and listed as a preset asset.

Click on the graph in the Settings column to open it.

Globals

Most nodes can be applied to the Globals chain, but some nodes can only be connected to the Globals chain. These settings can only be set once per render job and not per layer.

Most of these are present in the Movie Render Queue Preset in previous versions of Unreal Engine. For more information, see the Cinematic Rendering Image Quality Settings in Unreal Engine documentation.

Here you can reference a list of some of the Global Nodes you can use in the Movie Render Graph, and a description of the functionality:

Render Layer Nodes

The existence of the Render Layer node in your chain will signal for the Movie Render Graph to render this chain. Otherwise, logic will just be executed. The Render Layer Node is useful in Subgraphs or pipeline tools to better control the outcome of your render.

Along with disconnecting the chain from the Outputs tab, you can disable a render in the chain by right-mouse-clicking over the node and selecting the Disable property from the context menu.

Per-Render Layer Modifications

The following nodes are usable per-layer when using the Movie Render Graph.

Render Type Nodes

You have access to both the Pathtracer and Deferred renderers in the Movie Render Graph. You can define which render path you choose by connecting the correlating node in your chain. This can be chosen per render layer. This means you can have one layer take the Deferred render path and one take the Pathtracer in the same Render Graph.

Deferred Renderer

In the Deferred Renderer node you will find many parameters that can override Editor settings at render time, as well as set properties that must apply to all Render Layers. Here you can reference a list of the properties you can use with the Deferred Renderer node:

Path Traced Renderer

In the Path Traced Renderer node you will find many parameters that can override Editor settings at render time. Here you can reference a list of the available properties that you can use with the Path Traced Renderer node:

Output File Type Nodes

In the Movie Render Graph, you have the option of outputting many file types. You can pick the file output type per render chain.

The Movie Render Graph can output the following file types using the Output File Type node:

• WAV
• PNG
• JPG
• BMP
• EXR
• EXR Multilayer*
  • This can only be applied Globally
  • The first output will be in the RGBA. Any additional outputs will be listed in their own named layer.

You can define OpenColorIO (OCIO) configurations and compression type where applicable as well as file naming in the Output File Type Details panel.

You can also state the File Name here. The Movie Render Graph defaults to using the {sequence_name}.{layer_name}.{frame_number} tokens, Tokens can be used to dictate frame name as well as folder name in the Global Output Settings node.

If you clear the File Name Format property you can then select a different File Name Format from the drop-down menu.

Collection Node

The collections node allows you to gather and group different actors based on visibility attributes you would like to override in your level. Examples of this would be Background, Characters, Lights, Foliage, etc.

It is highly encouraged that you give each Collection node a unique name.

Condition Groups

Collections have a notion of Condition Groups. These are groups where you define the conditions that populate the collection. There are several conditions to choose from to enable you to traverse the level to get the desired actors.

The following are some wildcard examples for the String data type inputs, such as Actor Name, Actor Tag Name, and Component Tag Name.

• Foo* would match Foo, FooBar, and FooBaz, but not BarFoo.

• *Foo* would match the above in addition to BarFoo.

• Foo?Bar would match Foo.Bar and Foo_Bar, but not FooBar.

• Foo? would match Food, but not FooBar or BarFoo.

• Foo??? would match FooBar and FooBaz, but not Foo or Food.

• ?oo? would match Food, but not Foo.

• ?Foo* would match AFooBar, but not FooBar.

Condition Group Leveraging

You can add multiple conditions per group to create the membership. You can also leverage the conditions with and/or against each other. You can use Add, Subtract, and And.

This would include actors in any sublevel that matched CHAR_* and also any actor in the sublevel FG_SUBLEVEL regardless of its name.

You can even leverage multiple condition groups.

Additionally, you can have multiple complicated Condition Groups and leverage the Groups with, or against each other.

Condition Group Re-Ordering

If you hover over the left-hand side of a Condition Group or Condition Group Layer you will see ten dots show up in the UI and the mouse cursor icon will turn into a hand. You can then drag and drop to re-order the Conditions.

In-Editor Collection Membership Display

The arrow icon at the top of the details panel will resolve the node and select the actor members in the Engine.

A single actor can be a member of multiple Condition Groups and Collections. The Graph does not limit any membership under the hood and needs to be managed manually.

Collection Availability

Condition nodes anywhere in the graph will be available to any modifier node, no matter which chain they are connected to. Conditions in Subgraphs are available in Parent Graphs as well.

Spawnables

Due to the transient nature of Spawnables in the Engine, they have somewhat limited support in Movie Render Graph that will likely be improved in the future. In the collection node, you will need to get the spawnable actors by an applied Actor Tag. Note that there is a current limitation on tagged components. Those will not be retained in the level when the actor re-spawns due to Blueprint reconstruction. To tag components you will need to apply these render tags to the asset rather than the asset.

Modifier Node

Modifier nodes are used to control the visibility conditions of Collections. As with Collections, it is highly recommended to give each Modifier a unique name.

You set which Collection(s) the Modifier can control under the Collections section.

Under the Visibility section, there are five attributes and a Material slot that you can control on the actors in the Collection.

These parameters coincide with the same parameters on the Actor. The SkyAtmosphere and HeightFog Render in Main parameters are equivalent to Affect Indirect Lighting While Hidden. The Movie Render Graph makes this connection for you under the hood. Here you can reference a list of these properties and a description of their functionality:

If you do not see these attributes on a given actor type that means those types are not supported yet.

SkyAtmosphere and HeightFog actors have an attribute called Render In Main. This will essentially give you the same result as Affect Indirect Lighting While Hidden. There is one very big difference here though. For Render in Main to work the SkyAtmos and HeightFog actors need to be Visible. So these actor types will perhaps need to be treated separately in the Movie Render Graph, depending on your setup. The Holdout attribute works the same.

Using a Modifier Node

Let's take a look at a visual example here in the Meerkat sample project. In the first shot, we have the BG, an egg, and the meerkat.

If we toggle the Visible flag on the egg we see it disappear along with the shadow and reflections, as well as any sort of GI contribution to the scene.

If we enable Hidden Shadow on the egg we see the shadow come back.

Now if we enable the Lumen Overview we see that the egg is no longer in the Lumen scene, so it will not cast any reflections or GI.

If we enable Affect Indirect Lighting While Hidden and disable Screen Traces, we see the egg reappear in the Lumen Scene, along with GI occlusion and reflections in the viewport.

Now if we turn the Visibility back on, disable Affect Indirect Lighting While Hidden and Hidden Shadow, and enable the Holdout parameter you will see the egg has completely blacked out and is not poking a hole in the render. The alpha of this will render black as well.

It will still cast a shadow, and looking at the Lumen Scene, we see that the egg is still in there and will cast proper GI and reflections.

Burn-In and UI Renderer Nodes

The Burn-In node allows for adding custom watermarks to your render, which would typically be timecode-related. You can choose whether the burn-in is applied to the final image, or rendered to a separate layer. A default BurnIn class is provided that covers the basics of JobName, Date, Level Name, Author, Changelist, and camera information.

The UI Renderer node includes UMG widgets within the scene in the rendered output and provides flexibility by allowing the UMG-based elements to be in a separate Render Layer or composited into the final image.

Output

The output node is what sends the logic to the renderer. To create outputs you need to click on the plus icon in the Members tab under the OUTPUTS section.

If there is a Render Layer node in the chain plugged into an Output then that chain’s logic will be sent to the renderer. If there is no Render Layer node then the logic will be passed out of the Movie Render Graph, which is useful for pipeline tools and for use with Subgraphs. Outputs without a connection will do nothing.

Conditional Nodes

There are some logic nodes that can apply to the Movie Render Graph to control the computing of branches.

Branch Node

This node takes a True/False boolean as an input to let the Movie Render Graph which branch to compute.

For example, if you want to set up a single render layer but want to be able to choose whether it is rendered with the Pathtracer or the Deferred Path.

Select Node

This node takes an input to let Movie Render Graph know which branch to compute. You can select the desired data type for the input in the Details Panel of the Select node. If no option is stated the data will flow through the Default path.

For example, if you want to change which file type the renderer will write to:

Variables and Exposed Properties

Most nodes in the Movie Render Graph provide the ability to expose some of the properties as pins. This will allow you to promote these properties up to be set at the base Movie Render Queue UI rather than being hardcoded inside the Movie Render Graph. If you are familiar with Blueprints, this works similarly.

This is incredibly powerful when working in a source-controlled environment. Rather than having to have a graph per shot, you can expose desired parameters to be set at the job level rather than hard coded into the graph.

For example, if you want to be able to set Temporal Sampling differently for each shot in a sequence without having to make a Movie Render Graph per show, you can right-click on the Sampling Method node and expose the TemporalSampleCount parameter to a pin on the node.

Then you can right-click on the new exposed pin and select Promote to Variable.

This will automatically create a variable of the correct data type– in this case, an Integer:

This will now be available to be set on the job in your Queue.

Or you can use the Branch conditional to pick which Render Layers you want to render without having to dive into the graph asset.

Remove Render Setting

This node can be connected in a parent graph to remove any node of type in the subgraph.

A use case is if a subgraph has a JPG node that you don't want in your parent graph. You can connect the Remove Render Setting node in the parent graph to get rid of the JPG node.

Subgraphs

Subgraphs were created to give greater flexibility to base graphs in a source-controlled environment. Subgraphs are independently source-controlled Movie Render Graph assets that can be loaded into other Parent Graphs and still apply the logic. Parameters and/or logic can then be added, appended, or overridden.

In this screenshot, we are taking the output of the out_ENV render layer chain and creating a new Collection. Then splitting the Bugs out to their own render layer. This is an example of how an artist can make shot-level changes without having to check out and edit, or duplicate and edit, a sequence-level Movie Render Graph.

Graph Evaluation

You can see the results of the graph evaluation by pressing the Evaluate Graph button under the Active Render Settings tab.

The Movie Render Graph is evaluated from the Output backward, or from right to left. The graph composes left-to-right, where nodes closest to the Output node 'win' or have the highest precedence

You can see this in action here by breaking a chain and re-evaluating, or by setting the default condition status one way or another on a Branch node:

Limited or Non-supported Actor Types

There are still some actor types that have limited support in Render Layers. Generally, the lack of support will be for Holdout and Affect Indirect While Hidden will be the issue. Here you can reference the Actor types that have no, or limited support when using the Movie Render Graph:

Advanced Settings

Screen Traces

Lumen has some screen tracing elements enabled by default. This can interfere with some of the layer visibility settings being invoked by the graph. For example, if you would like your character to be visible to reflections and global illumination but hidden from primary pixels on a given layer, having Screen Traces enabled will cause the character to now show up in the Lumen Scene as desired, so it is recommended that you disable them.

There are several ways to disable Lumen screen traces.

• You can invoke the cvars:

  • r.Lumen.Reflections.ScreenTraces 0

  • r.Lumen.ScreenProbeGather.ScreenTraces 0

• You can disable them in the showflags both with a console command

  • ShowFlag.LumenScreenTraces 0

• And in the MRG Deferred Rendering node under the Show Flags section, which can also be promoted to a variable.

• As of 5.4, Screen Trace boolean parameters have been added to the Post Process Volume in both the Lumen Global Illumination and Lumen Reflections sections.

Note that disabling Lumen Screen Traces can change the look of your scene, so it is recommended to set these as you are lighting your level rather than purely as something toggled at render time.

Tone Curve

When working with translucent actors it is advised that you disable Tone Curve due to the fact that the alpha is pre-multiplied before curves/encodings are applied in the engine. So if you have a tone curve applied and try to render a partly translucent object on its own layer it will look differently when composited than what you see in-Engine. In this case, Tone Curve gives you non-linear colors which is undesirable for this type of composite. When using your own OCIO configuration, it will likely be necessary to disable the Tone Curve.

Allow OCIO

The Allow OCIO on the Deferred and Path Traced Rendering nodes offer an opt-out (defaults to on) for data-oriented Render Layers that are handled via Show Flags and Material Modifiers where OCIO would not be desirable.

Groom

• There are times when rendering Groom with motion blur in multiple layers can create some incorrect results. Consider trying the command *MoviePipeline.FlushLayersDebug 1 *to see improvements.

• To improve any halo around the groom when using holdouts consider the *r.HairStrands.HoldoutMode 1* command.

Example Content

A simple example Movie Render Graph is available in the Meerkat Sample project.

MRQ Config to Graph transition

The default Movie Render Graph is nearly identical to the default MRQ config. The main difference is that settings being placed in the graph are nodes that are more conducive to rendering in layers.

Exports

File Name Format

File Name Format has been moved to the File Type Output node. This will allow the user to control file naming settings per render layer.

Command Line Encoding

Settings

Anti Aliasing

Temporal and Spatial sampling settings have been split apart in the graph due to Temporal Samples needing to be set on the Global level while Spatial Samples can be set per render layer.

Temporal Samples are set in the Sampling Method node.

And Spatial Samples are now set on the Renderer node. Anti Aliasing Method can be set per render layer and is now located on the Renderer node as well.

Warm Up Settings

Warm Up settings have been simplified and given their own node:

Burn In

Camera Settings

Color Output

OCIO has been placed onto the File Type Output node as well for render layer level control rather than job level.

Tone Curve is now controlled on the Renderer node.

Console Variables

Debug Options

Write All Samples has been moved to the Renderer node

The ability to an Insights Trace or Capture frames for Render Dock is in the Debug Settings node

Game Overrides

The Game Overrides node exists in the graph by default and will no longer have any control over the render if deleted or disconnected, as opposed to the behavior on the config file.

Rendering

Render Path

The user can choose between the Path Tracer and Deferred rendering path by connecting their respective nodes to the render chain. This can be chosen per render layer.

View Mode Index

View Mode rendering is now on the Renderer node.

Additional Post-Processing Materials

Additional Post Process materials are located on the Renderer node and can be set per render layer.

UI Renderer

Currently Unsupported in Movie Render Graph

The following are features supported with MRQ, that do not have support when using MRG:

• nDisplay Rendering

• High Resolution Rendering

• Apple Pro Res plugin

• Final Cut Pro XML

• Prestreaming Recorder

• 32 Bit Post Process Material Rendering