bSupportsTemporalHistoryUpscale

bSupportsTemporalHistoryUpscale

#Overview

name: bSupportsTemporalHistoryUpscale

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 bSupportsTemporalHistoryUpscale is to indicate whether a specific shader platform supports temporal history upscaling, which is a technique used in rendering to improve image quality when upscaling lower resolution images.

This setting variable is primarily used within the RHI (Rendering Hardware Interface) module of Unreal Engine 5. It’s part of the data-driven shader platform information system, which allows the engine to adapt to different hardware capabilities across various platforms.

The value of this variable is set during the parsing of data-driven shader information. This occurs in the ParseDataDrivenShaderInfo function of the FGenericDataDrivenShaderPlatformInfo class, as seen in the DataDrivenShaderPlatformInfo.cpp file.

This variable interacts with other platform-specific capability flags, such as bSupportsLumenGI, bSupportsSSDIndirect, and bSupportsRTIndexFromVS. These flags collectively define the features supported by a particular shader platform.

Developers must be aware that this variable’s value depends on the specific hardware and graphics API being used. It’s not a setting that can be arbitrarily changed, but rather a capability flag that reflects the underlying hardware support.

Best practices when using this variable include:

1. Always check for support using the GetSupportsTemporalHistoryUpscale function before attempting to use temporal history upscaling features.
2. Design rendering pipelines with fallback options for platforms that don’t support this feature.
3. Use this information to optimize rendering paths, potentially enabling higher quality rendering on platforms that support temporal history upscaling.
4. Keep in mind that this is a low-level engine feature, and direct manipulation of this flag is generally not necessary in game code. Instead, use higher-level engine systems that abstract these hardware-specific details.

#Setting Variables

#References In INI files

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:74, section: [ShaderPlatform VULKAN_SM5]

• INI Section: ShaderPlatform VULKAN_SM5
• Raw value: false
• Is Array: False

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:193, section: [ShaderPlatform VULKAN_SM6]

• INI Section: ShaderPlatform VULKAN_SM6
• Raw value: false
• Is Array: False

#References in C++ code

#Callsites

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

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Private/DataDrivenShaderPlatformInfo.cpp:236

Scope (from outer to inner):

file
function     void FGenericDataDrivenShaderPlatformInfo::ParseDataDrivenShaderInfo

Source code excerpt:

	GET_SECTION_BOOL_HELPER(bSupportsLumenGI);
	GET_SECTION_BOOL_HELPER(bSupportsSSDIndirect);
	GET_SECTION_BOOL_HELPER(bSupportsTemporalHistoryUpscale);
	GET_SECTION_BOOL_HELPER(bSupportsRTIndexFromVS);
	GET_SECTION_BOOL_HELPER(bSupportsIntrinsicWaveOnce);
	GET_SECTION_BOOL_HELPER(bSupportsConservativeRasterization);
	GET_SECTION_SUPPORT_HELPER(bSupportsWaveOperations);
	GET_SECTION_BOOL_HELPER(bSupportsWavePermute);
	GET_SECTION_INT_HELPER(MinimumWaveSize);

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:60

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo

Source code excerpt:

	uint32 bSupportsLumenGI : 1;
	uint32 bSupportsSSDIndirect : 1;
	uint32 bSupportsTemporalHistoryUpscale : 1;
	uint32 bSupportsRTIndexFromVS : 1;
	uint32 bSupportsWaveOperations : int32(ERHIFeatureSupport::NumBits);
	uint32 bSupportsWavePermute : 1;
	uint32 MinimumWaveSize : 8;
	uint32 MaximumWaveSize : 8;
	uint32 bSupportsIntrinsicWaveOnce : 1;

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:449

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo
function     static const bool GetSupportsTemporalHistoryUpscale

Source code excerpt:

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

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