bSupportsSceneDataCompressedTransforms

bSupportsSceneDataCompressedTransforms

#Overview

name: bSupportsSceneDataCompressedTransforms

The value of this variable can be defined or overridden in .ini config files. 6 .ini config files referencing this setting variable.

It is referenced in 4 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of bSupportsSceneDataCompressedTransforms is to indicate whether a specific shader platform supports compressed transforms for scene data. This setting is related to the rendering system, specifically for optimizing memory usage and performance in scene representation.

This setting variable is primarily used within the RHI (Rendering Hardware Interface) module of Unreal Engine. It’s part of the data-driven shader platform information system, which allows for flexible configuration of shader platform capabilities.

The value of this variable is set during the parsing of data-driven shader information. This occurs in the ParseDataDrivenShaderInfo function within the FGenericDataDrivenShaderPlatformInfo class.

This variable interacts with other shader platform capability flags and settings within the FGenericDataDrivenShaderPlatformInfo class. It’s part of a larger set of properties that define the capabilities and behaviors of different shader platforms.

Developers must be aware that this setting is platform-specific. Its value can vary depending on the target hardware and graphics API. When developing rendering features or optimizations, checking this flag can help ensure compatibility and optimal performance across different platforms.

Best practices when using this variable include:

  1. Always check its value before attempting to use compressed transforms in scene data.
  2. Consider providing fallback methods for platforms that don’t support compressed transforms.
  3. Use the provided static accessor method (GetSupportSceneDataCompressedTransforms) to query this capability, rather than accessing the variable directly.
  4. Be aware of how this setting interacts with other rendering optimizations and adjust your rendering pipeline accordingly.
  5. When developing cross-platform applications, test thoroughly on platforms both with and without this capability to ensure correct behavior in all scenarios.

#Setting Variables

#References In INI files

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:67, section: [ShaderPlatform VULKAN_SM5]

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:186, section: [ShaderPlatform VULKAN_SM6]

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:272, section: [ShaderPlatform VULKAN_PCES3_1]

Location: <Workspace>/Engine/Config/Windows/DataDrivenPlatformInfo.ini:51, section: [ShaderPlatform PCD3D_SM5]

Location: <Workspace>/Engine/Config/Windows/DataDrivenPlatformInfo.ini:102, section: [ShaderPlatform PCD3D_SM6]

Location: <Workspace>/Engine/Config/Windows/DataDrivenPlatformInfo.ini:158, section: [ShaderPlatform PCD3D_ES3_1]

#References in C++ code

#Callsites

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

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Private/DataDrivenShaderPlatformInfo.cpp:286

Scope (from outer to inner):

file
function     void FGenericDataDrivenShaderPlatformInfo::ParseDataDrivenShaderInfo

Source code excerpt:

	GET_SECTION_SUPPORT_HELPER(bSupportsRealTypes);
	GET_SECTION_INT_HELPER(EnablesHLSL2021ByDefault);
	GET_SECTION_BOOL_HELPER(bSupportsSceneDataCompressedTransforms);
	GET_SECTION_BOOL_HELPER(bSupportsSwapchainUAVs);
	GET_SECTION_BOOL_HELPER(bSupportsClipDistance);
	GET_SECTION_BOOL_HELPER(bSupportsNNEShaders);
	GET_SECTION_BOOL_HELPER(bSupportsShaderPipelines);
	GET_SECTION_BOOL_HELPER(bSupportsUniformBufferObjects);
	GET_SECTION_BOOL_HELPER(bRequiresBindfulUtilityShaders);

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Private/DataDrivenShaderPlatformInfo.cpp:471

Scope (from outer to inner):

file
function     void FGenericDataDrivenShaderPlatformInfo::UpdatePreviewPlatforms

Source code excerpt:

				PREVIEW_USE_RUNTIME_VALUE(bSupportsGPUScene);
				PREVIEW_USE_RUNTIME_VALUE(MaxMeshShaderThreadGroupSize);
				PREVIEW_USE_RUNTIME_VALUE(bSupportsSceneDataCompressedTransforms);
				PREVIEW_USE_RUNTIME_VALUE(bSupportsVertexShaderSRVs);
				PREVIEW_USE_RUNTIME_VALUE(bSupportsManualVertexFetch);
				PREVIEW_USE_RUNTIME_VALUE(bSupportsRealTypes);
				PREVIEW_USE_RUNTIME_VALUE(bSupportsUniformBufferObjects);

				// Settings that will never be supported in preview

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:111

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo

Source code excerpt:

	uint32 bSupportsRealTypes : int32(ERHIFeatureSupport::NumBits);
	uint32 EnablesHLSL2021ByDefault : 2; // 0: disabled, 1: global shaders only, 2: all shaders
	uint32 bSupportsSceneDataCompressedTransforms : 1;
	uint32 bIsPreviewPlatform : 1;
	uint32 bSupportsSwapchainUAVs : 1;
	uint32 bSupportsClipDistance : 1;
	uint32 bSupportsNNEShaders: 1;
	uint32 bSupportsShaderPipelines : 1;
	uint32 bSupportsUniformBufferObjects : 1;

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:335

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo
function     static const bool GetSupportSceneDataCompressedTransforms

Source code excerpt:

	{
		check(IsValid(Platform));
		return Infos[Platform].bSupportsSceneDataCompressedTransforms;
	}

	static FORCEINLINE_DEBUGGABLE const bool GetSupportsRayTracing(const FStaticShaderPlatform Platform)
	{
		check(IsValid(Platform));
		return Infos[Platform].bSupportsRayTracing;