a.URO.Enable

a.URO.Enable

#Overview

name: a.URO.Enable

This variable is created as a Console Variable (cvar).

• type: Var
• help: True to anim rate optimization.

It is referenced in 7 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of a.URO.Enable is to control the Animation Update Rate Optimization (URO) feature in Unreal Engine’s animation system. This setting is used to enable or disable the optimization of animation update rates, which can help improve performance in certain scenarios.

Unreal Engine subsystems that rely on this setting variable include:

1. The animation system, specifically within the SkinnedMeshComponent
2. The MovieRenderPipeline plugin

The value of this variable is set in two ways:

1. As a console variable with a default value of 1 (enabled)
2. Explicitly set to 0 (disabled) in certain scenarios, such as during movie rendering

The associated variable CVarEnableAnimRateOptimization interacts directly with a.URO.Enable. They share the same value and are used interchangeably in the code.

Developers should be aware of the following when using this variable:

1. Enabling URO (value set to 1) can improve performance in runtime games by optimizing animation update rates.
2. Disabling URO (value set to 0) ensures consistent animation behavior, which is crucial for tasks like movie rendering where frame-perfect accuracy is required.
3. The variable is automatically disabled in certain pipeline processes, such as the MovieRenderPipeline, to ensure consistent results.

Best practices when using this variable include:

1. Leave it enabled (default value of 1) for most runtime game scenarios to benefit from performance optimizations.
2. Disable it (set to 0) when working on tasks that require frame-perfect animation accuracy, such as cinematic rendering or debugging animation issues.
3. Be aware that some Unreal Engine processes may override this setting automatically, so always check its current value when investigating animation-related issues.

Regarding the associated variable CVarEnableAnimRateOptimization:

• It serves the same purpose as a.URO.Enable and is used interchangeably in the code.
• It is defined as a console variable in the SkinnedMeshComponent.cpp file.
• The ShouldUseUpdateRateOptimizations() function in the USkinnedMeshComponent class uses this variable to determine if update rate optimizations should be applied.
• When working with animation systems or investigating performance issues related to animations, developers should consider both a.URO.Enable and CVarEnableAnimRateOptimization as they represent the same setting.

#References in C++ code

#Callsites

This variable is referenced in the following C++ source code:

#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/Components/SkinnedMeshComponent.cpp:54

Scope: file

Source code excerpt:

static TAutoConsoleVariable<int32> CVarEnableAnimRateOptimization(
	TEXT("a.URO.Enable"),
	1,
	TEXT("True to anim rate optimization."));

static TAutoConsoleVariable<int32> CVarDrawAnimRateOptimization(
	TEXT("a.URO.Draw"),
	0,

#Loc: <Workspace>/Engine/Plugins/MovieScene/MovieRenderPipeline/Source/MovieRenderPipelineCore/Private/Graph/Nodes/MovieGraphGlobalGameOverrides.cpp:77

Scope (from outer to inner):

file
function     void UMovieGraphGlobalGameOverridesNode::BuildNewProcessCommandLineArgsImpl

Source code excerpt:

#endif

	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("a.URO.Enable=%d"), 0));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("r.SkyLight.RealTimeReflectionCapture.TimeSlice=%d"), 0));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("r.VolumetricRenderTarget=%d"), 1));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("r.VolumetricRenderTarget.Mode=%d"), 3));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("wp.Runtime.BlockOnSlowStreaming=%d"), 0));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("p.Chaos.ImmPhys.MinStepTime=%d"), 0));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("r.SkipRedundantTransformUpdate=%d"), 0));

#Loc: <Workspace>/Engine/Plugins/MovieScene/MovieRenderPipeline/Source/MovieRenderPipelineCore/Private/Graph/Nodes/MovieGraphGlobalGameOverrides.cpp:147

Scope (from outer to inner):

file
function     void UMovieGraphGlobalGameOverridesNode::ApplySettings

Source code excerpt:

		// Disable systems that try to preserve performance in runtime games.
		MOVIEPIPELINE_STORE_AND_OVERRIDE_CVAR_INT(PreviousAnimationUROEnabled, TEXT("a.URO.Enable"), 0, bOverrideValues);

		// To make sure that the skylight is always valid and consistent across capture sessions, we enforce a full capture each frame, accepting a small GPU cost.
		MOVIEPIPELINE_STORE_AND_OVERRIDE_CVAR_INT(PreviousSkyLightRealTimeReflectionCaptureTimeSlice, TEXT("r.SkyLight.RealTimeReflectionCapture.TimeSlice"), 0, bOverrideValues);

		// Cloud are rendered using high quality volumetric render target mode 3: per pixel tracing and composition on screen, while supporting cloud on translucent.
		MOVIEPIPELINE_STORE_AND_OVERRIDE_CVAR_INT(PreviousVolumetricRenderTarget, TEXT("r.VolumetricRenderTarget"), 1, bOverrideValues);

#Loc: <Workspace>/Engine/Plugins/MovieScene/MovieRenderPipeline/Source/MovieRenderPipelineCore/Private/MoviePipelineGameOverrideSetting.cpp:111

Scope (from outer to inner):

file
function     void UMoviePipelineGameOverrideSetting::ApplyCVarSettings

Source code excerpt:

	{
		// Disable systems that try to preserve performance in runtime games.
		MOVIEPIPELINE_STORE_AND_OVERRIDE_CVAR_INT(PreviousAnimationUROEnabled, TEXT("a.URO.Enable"), 0, bOverrideValues);
	}

	MOVIEPIPELINE_STORE_AND_OVERRIDE_CVAR_INT(PreviousNeverMuteNonRealtimeAudio, TEXT("au.NeverMuteNonRealtimeAudioDevices"), 1, bOverrideValues);

	// To make sure that the skylight is always valid and consistent accross capture sessions, we enforce a full capture each frame, accepting a small GPU cost.
	MOVIEPIPELINE_STORE_AND_OVERRIDE_CVAR_INT(PreviousSkyLightRealTimeReflectionCaptureTimeSlice, TEXT("r.SkyLight.RealTimeReflectionCapture.TimeSlice"), 0, bOverrideValues);

#Loc: <Workspace>/Engine/Plugins/MovieScene/MovieRenderPipeline/Source/MovieRenderPipelineCore/Private/MoviePipelineGameOverrideSetting.cpp:233

Scope (from outer to inner):

file
function     void UMoviePipelineGameOverrideSetting::BuildNewProcessCommandLineArgsImpl

Source code excerpt:

	{
		InOutDeviceProfileCvars.Add(FString::Printf(TEXT("a.URO.Enable=%d"), 0));
	}

	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("au.NeverMuteNonRealtimeAudioDevices=%d"), 1));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("r.SkyLight.RealTimeReflectionCapture.TimeSlice=%d"), 0));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("r.VolumetricRenderTarget=%d"), 1));
	InOutDeviceProfileCvars.Add(FString::Printf(TEXT("r.VolumetricRenderTarget.Mode=%d"), 3));

#Associated Variable and Callsites

This variable is associated with another variable named CVarEnableAnimRateOptimization. They share the same value. See the following C++ source code.

#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/Components/SkinnedMeshComponent.cpp:53

Scope: file

Source code excerpt:

	);

static TAutoConsoleVariable<int32> CVarEnableAnimRateOptimization(
	TEXT("a.URO.Enable"),
	1,
	TEXT("True to anim rate optimization."));

static TAutoConsoleVariable<int32> CVarDrawAnimRateOptimization(
	TEXT("a.URO.Draw"),

#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/Components/SkinnedMeshComponent.cpp:1356

Scope (from outer to inner):

file
function     bool USkinnedMeshComponent::ShouldUseUpdateRateOptimizations

Source code excerpt:

bool USkinnedMeshComponent::ShouldUseUpdateRateOptimizations() const
{
	return bEnableUpdateRateOptimizations && CVarEnableAnimRateOptimization.GetValueOnAnyThread() > 0;
}

void USkinnedMeshComponent::TickPose(float DeltaTime, bool bNeedsValidRootMotion)
{
	OnTickPose.Broadcast(this, DeltaTime, bNeedsValidRootMotion);
	TickUpdateRate(DeltaTime, bNeedsValidRootMotion);