bRequiresRenderTargetDuringRaster

bRequiresRenderTargetDuringRaster

#Overview

name: bRequiresRenderTargetDuringRaster

The value of this variable can be defined or overridden in .ini config files. 2 .ini config files referencing this setting variable.

It is referenced in 3 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of bRequiresRenderTargetDuringRaster is to indicate whether a specific shader platform requires a render target to be bound during the rasterization process.

This setting variable is primarily used in the Rendering Hardware Interface (RHI) subsystem of Unreal Engine 5. It is part of the data-driven shader platform information system, which allows for platform-specific rendering configurations.

The value of this variable is set in the FGenericDataDrivenShaderPlatformInfo class, specifically in the ParseDataDrivenShaderInfo function. It is parsed from a configuration section, likely loaded from an INI file or similar configuration source.

bRequiresRenderTargetDuringRaster interacts with other platform-specific rendering capabilities, such as bSupportsDualSourceBlending, bRequiresGeneratePrevTransformBuffer, and bRequiresDisableForwardLocalLights. These variables collectively define the rendering capabilities and requirements for a specific shader platform.

Developers must be aware that this variable can affect the rendering pipeline’s behavior. If set to true, it indicates that the rendering system must ensure a render target is bound during the rasterization stage, which may have performance implications or be necessary for certain rendering techniques on specific platforms.

Best practices when using this variable include:

  1. Ensure it is correctly set for each supported shader platform in your project’s configuration files.
  2. Consider its value when implementing custom rendering techniques or optimizations.
  3. Be aware of its potential impact on performance and memory usage, especially on platforms where it is set to true.
  4. Use the GetRequiresRenderTargetDuringRaster function to query this value in your rendering code, rather than accessing the variable directly.
  5. Consider this setting when debugging rendering issues across different platforms, as it may explain differences in behavior or performance.

#Setting Variables

#References In INI files

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:103, section: [ShaderPlatform VULKAN_SM5]

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:222, section: [ShaderPlatform VULKAN_SM6]

#References in C++ code

#Callsites

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

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Private/DataDrivenShaderPlatformInfo.cpp:252

Scope (from outer to inner):

file
function     void FGenericDataDrivenShaderPlatformInfo::ParseDataDrivenShaderInfo

Source code excerpt:

	GET_SECTION_BOOL_HELPER(bSupportsDualSourceBlending);
	GET_SECTION_BOOL_HELPER(bRequiresGeneratePrevTransformBuffer);
	GET_SECTION_BOOL_HELPER(bRequiresRenderTargetDuringRaster);
	GET_SECTION_BOOL_HELPER(bRequiresDisableForwardLocalLights);
	GET_SECTION_BOOL_HELPER(bCompileSignalProcessingPipeline);
	GET_SECTION_BOOL_HELPER(bSupportsMeshShadersTier0);
	GET_SECTION_BOOL_HELPER(bSupportsMeshShadersTier1);
	GET_SECTION_BOOL_HELPER(bSupportsMeshShadersWithClipDistance);
	GET_SECTION_INT_HELPER(MaxMeshShaderThreadGroupSize);

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:76

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo

Source code excerpt:

	uint32 bSupportsDualSourceBlending : 1;
	uint32 bRequiresGeneratePrevTransformBuffer : 1;
	uint32 bRequiresRenderTargetDuringRaster : 1;
	uint32 bRequiresDisableForwardLocalLights : 1;
	uint32 bCompileSignalProcessingPipeline : 1;
	uint32 bSupportsMeshShadersTier0 : 1;
	uint32 bSupportsMeshShadersTier1 : 1;
	uint32 bSupportsMeshShadersWithClipDistance : 1;
	uint32 MaxMeshShaderThreadGroupSize : 10;

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:539

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo
function     static const bool GetRequiresRenderTargetDuringRaster

Source code excerpt:

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

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