bSupportsIndexBufferUAVs

bSupportsIndexBufferUAVs

#Overview

name: bSupportsIndexBufferUAVs

The value of this variable can be defined or overridden in .ini config files. 10 .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 bSupportsIndexBufferUAVs is to indicate whether the current graphics hardware and shader platform support Unordered Access Views (UAVs) for index buffers. This feature is related to the rendering system, specifically the ability to perform read and write operations on index buffers in compute shaders.

This setting variable is primarily used within the RHI (Rendering Hardware Interface) module of Unreal Engine 5. It’s part of the FGenericDataDrivenShaderPlatformInfo class, which provides information about various shader platform capabilities.

The value of this variable is set during the parsing of data-driven shader information, as seen in the ParseDataDrivenShaderInfo function in DataDrivenShaderPlatformInfo.cpp. It’s likely populated from a configuration file or platform-specific data.

This variable interacts with other shader platform capability flags, such as bSupportsCapsuleShadows, bSupportsPercentageCloserShadows, and bSupportsInstancedStereo. These flags collectively define the features supported by a specific shader platform.

Developers must be aware that this variable is platform-specific and its value may change depending on the target hardware. It’s crucial to check this flag before attempting to use index buffer UAVs in shader code or when setting up rendering pipelines that rely on this feature.

Best practices when using this variable include:

1. Always check the value of this flag before using index buffer UAVs in your rendering code.
2. Provide fallback methods for platforms that don’t support this feature.
3. Use the provided GetSupportsIndexBufferUAVs() static function to query this capability, ensuring type safety and proper initialization checks.
4. Consider the performance implications of using index buffer UAVs and only use them when necessary, as they can impact rendering performance on some hardware.

#Setting Variables

#References In INI files

Location: <Workspace>/Engine/Config/Android/DataDrivenPlatformInfo.ini:84, section: [ShaderPlatform VULKAN_ES3_1_ANDROID]

• INI Section: ShaderPlatform VULKAN_ES3_1_ANDROID
• Raw value: true
• Is Array: False

Location: <Workspace>/Engine/Config/Android/DataDrivenPlatformInfo.ini:103, section: [ShaderPlatform VULKAN_SM5_ANDROID]

• INI Section: ShaderPlatform VULKAN_SM5_ANDROID
• Raw value: true
• Is Array: False

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

• INI Section: ShaderPlatform METAL_MRT
• Raw value: true
• Is Array: False

Location: <Workspace>/Engine/Config/Mac/DataDrivenPlatformInfo.ini:118, section: [ShaderPlatform METAL_MRT_MAC]

• INI Section: ShaderPlatform METAL_MRT_MAC
• Raw value: true
• Is Array: False

Location: <Workspace>/Engine/Config/TVOS/DataDrivenPlatformInfo.ini:25, section: [ShaderPlatform METAL_MRT_TVOS]

• INI Section: ShaderPlatform METAL_MRT_TVOS
• Raw value: true
• Is Array: False

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:37, section: [ShaderPlatform VULKAN_SM5]

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

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:165, section: [ShaderPlatform VULKAN_SM6]

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

Location: <Workspace>/Engine/Config/VulkanPC/DataDrivenPlatformInfo.ini:268, section: [ShaderPlatform VULKAN_PCES3_1]

• INI Section: ShaderPlatform VULKAN_PCES3_1
• Raw value: true
• Is Array: False

Location: <Workspace>/Engine/Config/Windows/DataDrivenPlatformInfo.ini:69, section: [ShaderPlatform PCD3D_SM5]

• INI Section: ShaderPlatform PCD3D_SM5
• Raw value: true
• Is Array: False

Location: <Workspace>/Engine/Config/Windows/DataDrivenPlatformInfo.ini:128, section: [ShaderPlatform PCD3D_SM6]

• INI Section: ShaderPlatform PCD3D_SM6
• Raw value: true
• 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:211

Scope (from outer to inner):

file
function     void FGenericDataDrivenShaderPlatformInfo::ParseDataDrivenShaderInfo

Source code excerpt:

	GET_SECTION_BOOL_HELPER(bSupportsCapsuleShadows);
	GET_SECTION_BOOL_HELPER(bSupportsPercentageCloserShadows);
	GET_SECTION_BOOL_HELPER(bSupportsIndexBufferUAVs);
	GET_SECTION_BOOL_HELPER(bSupportsInstancedStereo);
	GET_SECTION_SUPPORT_HELPER(SupportsMultiViewport);
	GET_SECTION_BOOL_HELPER(bSupportsMSAA);
	GET_SECTION_BOOL_HELPER(bSupports4ComponentUAVReadWrite);
	GET_SECTION_BOOL_HELPER(bSupportsShaderRootConstants);
	GET_SECTION_BOOL_HELPER(bSupportsShaderBundleDispatch);

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:37

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo

Source code excerpt:

	uint32 bSupportsCapsuleShadows : 1;
	uint32 bSupportsPercentageCloserShadows : 1;
	uint32 bSupportsIndexBufferUAVs : 1;
	uint32 bSupportsInstancedStereo : 1;
	uint32 SupportsMultiViewport : int32(ERHIFeatureSupport::NumBits);
	uint32 bSupportsMSAA : 1;
	uint32 bSupports4ComponentUAVReadWrite : 1;
	uint32 bSupportsShaderRootConstants : 1;
	uint32 bSupportsShaderBundleDispatch : 1;

#Loc: <Workspace>/Engine/Source/Runtime/RHI/Public/DataDrivenShaderPlatformInfo.h:281

Scope (from outer to inner):

file
class        class FGenericDataDrivenShaderPlatformInfo
function     static const bool GetSupportsIndexBufferUAVs

Source code excerpt:

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

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