#include "LumenReSTIRGather.h"
#include "LumenScreenProbeGather.h"
#include "BasePassRendering.h"
#include "Lumen/LumenRadianceCache.h"
#include "RendererPrivate.h"
#include "ScenePrivate.h"
#include "SceneUtils.h"
#include "PipelineStateCache.h"
#include "ShaderParameterStruct.h"
#include "PixelShaderUtils.h"
#include "ReflectionEnvironment.h"
#include "DistanceFieldAmbientOcclusion.h"
#include "ScreenSpaceDenoise.h"
#include "HairStrands/HairStrandsEnvironment.h"
#include "ShaderPrint.h"
#include "Substrate/Substrate.h"
#include "LumenReflections.h"
#include "DepthCopy.h"

Classes
class	FTemporalResamplingCS

class	FClearTemporalHistoryCS

class	FSpatialResamplingCS

class	FUpsampleAndIntegrateCS

class	FTemporalAccumulationCS

class	FBilateralFilterCS

Namespaces
namespace	LumenReSTIRGather

namespace	Lumen

Enumerations
enum class	EReSTIRUpsampleMethod : uint8 { JitteredBilinearWithFallback , SpiralPattern , Passthrough , MAX }

Functions
FAutoConsoleVariableRef	CVarLumenReSTIRDownsampleFactor (TEXT("r.Lumen.ReSTIRGather.DownsampleFactor"), GLumenReSTIRDownsampleFactor, TEXT("Downsample factor from the main viewport to trace rays, create and resample reservoirs at. This is the main performance control for the tracing / resampling part of the algorithm."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRTemporalResampling (TEXT("r.Lumen.ReSTIRGather.TemporalResampling"), GLumenReSTIRTemporalResampling, TEXT("Whether to do a temporal resampling pass on the reservoirs"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRTemporalResamplingValidate (TEXT("r.Lumen.ReSTIRGather.TemporalResampling.ValidateEveryNFrames"), GLumenReSTIRValidateTemporalReservoirsEveryNFrames, TEXT("Validate temporal reservoirs by re-tracing their rays and comparing hit positions and radiance every N frames. Used to reduce lag in lighting changes, but introduces noise."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarReSTIRTemporalResamplingHistoryDistanceThreshold (TEXT("r.Lumen.ReSTIRGather.TemporalResampling.DistanceThreshold"), GLumenReSTIRTemporalResamplingHistoryDistanceThreshold, TEXT(""), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRTemporalResamplingResetHistory (TEXT("r.Lumen.ReSTIRGather.TemporalResampling.ResetHistory"), GLumenReSTIRTemporalResamplingResetHistory, TEXT(""), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRSpatialResampling (TEXT("r.Lumen.ReSTIRGather.SpatialResampling"), GLumenReSTIRSpatialResampling, TEXT("Whether to use spatial resampling passes on the reservoirs"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenNumSpatialResamplingPasses (TEXT("r.Lumen.ReSTIRGather.SpatialResampling.NumPasses"), GLumenReSTIRNumSpatialResamplingPasses, TEXT("The number of spatial resampling passes to do"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRNumSpatialSamples (TEXT("r.Lumen.ReSTIRGather.SpatialResampling.NumSamples"), GLumenReSTIRNumSpatialSamples, TEXT("The number of spatial samples for each resampling pass."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRSpatialResamplingKernelRadius (TEXT("r.Lumen.ReSTIRGather.SpatialResampling.KernelRadius"), GLumenReSTIRSpatialResamplingKernelRadius, TEXT("Radius of the spatial resampling kernel as a fraction of the screen."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRResamplingAngleThreshold (TEXT("r.Lumen.ReSTIRGather.ResamplingAngleThreshold"), GLumenReSTIRResamplingAngleThreshold, TEXT("Largest angle between two reservoirs that will be allowed during reservoir resampling, in degrees"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRSpatialResamplingDepthErrorThreshold (TEXT("r.Lumen.ReSTIRGather.ResamplingDepthErrorThreshold"), GLumenReSTIRResamplingDepthErrorThreshold, TEXT("Largest depth error between two reservoirs that will be allowed during reservoir resampling"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance (TEXT("r.Lumen.ReSTIRGather.SpatialResampling.OcclusionScreenTraceDistance"), GLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance, TEXT("Length of occlusion screen traces used to validate the neighbor's reservoir hit position before reuse, to reduce leaking. As a fraction of the screen size."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRMaxRayIntensity (TEXT("r.Lumen.ReSTIRGather.MaxRayIntensity"), GLumenReSTIRMaxRayIntensity, TEXT("Clamps the maximum ray lighting intensity (with PreExposure) to reduce fireflies."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRUpsampleMethod (TEXT("r.Lumen.ReSTIRGather.Upsample.Method"), GLumenReSTIRUpsampleMethod, TEXT("2 - Passthrough for debugging. Also effectively disables the bilateral filter as variance is not computed."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRUpsampleKernelSize (TEXT("r.Lumen.ReSTIRGather.Upsample.KernelSize"), GLumenReSTIRUpsampleKernelSize, TEXT("Upsample kernel size, in reservoir texels"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRNumSamples (TEXT("r.Lumen.ReSTIRGather.Upsample.NumSamples"), GLumenReSTIRUpsampleNumSamples, TEXT("Number of reservoir samples to take while upsampling. Only used when r.Lumen.ReSTIRGather.Upsample.Method is set to Spiral Pattern."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherTemporalFilter (TEXT("r.Lumen.ReSTIRGather.Temporal"), GLumenReSTIRGatherTemporalFilter, TEXT("Whether to use a temporal filter"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherHistoryDistanceThreshold (TEXT("r.Lumen.ReSTIRGather.Temporal.DistanceThreshold"), GLumenReSTIRGatherHistoryDistanceThreshold, TEXT("Relative distance threshold needed to discard last frame's lighting results. Lower values reduce ghosting from characters when near a wall but increase flickering artifacts."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherTemporalMaxFramesAccumulated (TEXT("r.Lumen.ReSTIRGather.Temporal.MaxFramesAccumulated"), GLumenReSTIRGatherTemporalMaxFramesAccumulated, TEXT("Lower values cause the temporal filter to propagate lighting changes faster, but also increase flickering from noise."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherBilateralFilter (TEXT("r.Lumen.ReSTIRGather.BilateralFilter"), GLumenReSTIRGatherBilateralFilter, TEXT("Whether to do a bilateral filter as a last step in denoising Lumen ReSTIRGathers."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherBilateralFilterSpatialKernelRadius (TEXT("r.Lumen.ReSTIRGather.BilateralFilter.SpatialKernelRadius"), GLumenReSTIRGatherBilateralFilterSpatialKernelRadius, TEXT("Spatial kernel radius, as a fraction of the viewport size"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherBilateralFilterNumSamples (TEXT("r.Lumen.ReSTIRGather.BilateralFilter.NumSamples"), GLumenReSTIRGatherBilateralFilterNumSamples, TEXT("Number of bilateral filter samples."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherBilateralFilterDepthWeightScale (TEXT("r.Lumen.ReSTIRGather.BilateralFilter.DepthWeightScale"), GLumenReSTIRGatherBilateralFilterDepthWeightScale, TEXT("Scales the depth weight of the bilateral filter"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale (TEXT("r.Lumen.ReSTIRGather.BilateralFilter.NormalAngleThresholdScale"), GLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale, TEXT("Scales the Normal angle threshold of the bilateral filter"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold (TEXT("r.Lumen.ReSTIRGather.BilateralFilter.StrongBlurVarianceThreshold"), GLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold, TEXT("Pixels whose variance from the spatial resolve filter are higher than this value get a stronger bilateral blur."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenReSTIRGatherShortRangeAO (TEXT("r.Lumen.ReSTIRGather.ShortRangeAO"), GLumenReSTIRGatherShortRangeAmbientOcclusion, TEXT("Whether to compute a short range, full resolution AO to add high frequency occlusion (contact shadows) which ReSTIR GI lacks due to spatial filtering."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction (TEXT("r.Lumen.ReSTIRGather.ShortRangeAO.MaxScreenTraceFraction"), GLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction, TEXT("Short range AO tracing distance, as a fraction of the screen size."), ECVF_Scalability\|ECVF_RenderThreadSafe)

int32	LumenReSTIRGather::GetScreenDownsampleFactor (const FViewInfo &View)

bool	DoesPlatformSupportLumenReSTIRGather (EShaderPlatform Platform)

bool	Lumen::UseReSTIRGather (const FSceneViewFamily &ViewFamily, EShaderPlatform ShaderPlatform)

	IMPLEMENT_GLOBAL_SHADER (FTemporalResamplingCS, "/Engine/Private/Lumen/LumenReSTIRGather.usf", "TemporalResamplingCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FClearTemporalHistoryCS, "/Engine/Private/Lumen/LumenReSTIRGather.usf", "ClearTemporalHistoryCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FSpatialResamplingCS, "/Engine/Private/Lumen/LumenReSTIRGather.usf", "SpatialResamplingCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FUpsampleAndIntegrateCS, "/Engine/Private/Lumen/LumenReSTIRGather.usf", "UpsampleAndIntegrateCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FTemporalAccumulationCS, "/Engine/Private/Lumen/LumenReSTIRGather.usf", "TemporalAccumulationCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FBilateralFilterCS, "/Engine/Private/Lumen/LumenReSTIRGather.usf", "BilateralFilterCS", SF_Compute)

void	DispatchTemporalAccumulation (FRDGBuilder &GraphBuilder, const FViewInfo &View, const FSceneTextures &SceneTextures, FLumenSceneFrameTemporaries &FrameTemporaries, bool bPropagateGlobalLightingChange, bool bUseBilaterialFilter, FRDGTextureRef &DiffuseIndirect, FRDGTextureRef &RoughSpecularIndirect, FRDGTextureRef &ResolveVariance, ERDGPassFlags ComputePassFlags)

FReservoirTextures	AllocateReservoirTextures (FRDGBuilder &GraphBuilder, FLumenSceneFrameTemporaries &FrameTemporaries, FIntPoint ReservoirBufferSize, FIntPoint ReservoirViewExtent)

FReservoirUAVs	CreateReservoirUAVs (FRDGBuilder &GraphBuilder, const FReservoirTextures &Textures)

Variables
int32	GLumenReSTIRDownsampleFactor = 2

int32	GLumenReSTIRGatherFixedJitterIndex = -1

FAutoConsoleVariableRef	CVarLumenReSTIRGatherFixedJitterIndex (TEXT("r.Lumen.ReSTIRGather.FixedJitterIndex"), GLumenReSTIRGatherFixedJitterIndex, TEXT("When 0 or larger, overrides the frame index with a constant for debugging"), ECVF_RenderThreadSafe)

int32	GLumenReSTIRTemporalResampling = 1

int32	GLumenReSTIRValidateTemporalReservoirsEveryNFrames = 0

float	GLumenReSTIRTemporalResamplingHistoryDistanceThreshold = .005f

int32	GLumenReSTIRTemporalResamplingResetHistory = 0

int32	GLumenReSTIRSpatialResampling = 1

int32	GLumenReSTIRNumSpatialResamplingPasses = 2

int32	GLumenReSTIRNumSpatialSamples = 4

float	GLumenReSTIRSpatialResamplingKernelRadius = .05f

float	GLumenReSTIRResamplingAngleThreshold = 25.0f

float	GLumenReSTIRResamplingDepthErrorThreshold = .01f

float	GLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance = .2f

float	GLumenReSTIRMaxRayIntensity = 100

int32	GLumenReSTIRUpsampleMethod = 1

float	GLumenReSTIRUpsampleKernelSize = 3.0f

int32	GLumenReSTIRUpsampleNumSamples = 16

int32	GLumenReSTIRGatherTemporalFilter = 1

int32	GLumenReSTIRGatherClearHistoryEveryFrame = 0

FAutoConsoleVariableRef	CVarLumenReSTIRGatherClearHistoryEveryFrame (TEXT("r.Lumen.ReSTIRGather.Temporal.ClearHistoryEveryFrame"), GLumenReSTIRGatherClearHistoryEveryFrame, TEXT("Whether to clear the history every frame for debugging"), ECVF_RenderThreadSafe)

float	GLumenReSTIRGatherHistoryDistanceThreshold = .005f

float	GLumenReSTIRGatherTemporalMaxFramesAccumulated = 10.0f

int32	GLumenReSTIRGatherBilateralFilter = 1

float	GLumenReSTIRGatherBilateralFilterSpatialKernelRadius = .002f

int32	GLumenReSTIRGatherBilateralFilterNumSamples = 8

float	GLumenReSTIRGatherBilateralFilterDepthWeightScale = 10000.0f

float	GLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale = .2f

float	GLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold = .5f

int32	GLumenReSTIRGatherShortRangeAmbientOcclusion = 1

float	GLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction = .02f

Enumeration Type Documentation

◆ EReSTIRUpsampleMethod

enum class EReSTIRUpsampleMethod : uint8

strong

Enumerator
JitteredBilinearWithFallback
SpiralPattern
Passthrough
MAX

Function Documentation

◆ AllocateReservoirTextures()

FReservoirTextures AllocateReservoirTextures	(	FRDGBuilder &	GraphBuilder,
		FLumenSceneFrameTemporaries &	FrameTemporaries,
		FIntPoint	ReservoirBufferSize,
		FIntPoint	ReservoirViewExtent
	)

◆ CreateReservoirUAVs()

FReservoirUAVs CreateReservoirUAVs	(	FRDGBuilder &	GraphBuilder,
		const FReservoirTextures &	Textures
	)

◆ CVarLumenNumSpatialResamplingPasses()

FAutoConsoleVariableRef CVarLumenNumSpatialResamplingPasses	(	TEXT("r.Lumen.ReSTIRGather.SpatialResampling.NumPasses")	,
		GLumenReSTIRNumSpatialResamplingPasses	,
		TEXT("The number of spatial resampling passes to do")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRDownsampleFactor()

FAutoConsoleVariableRef CVarLumenReSTIRDownsampleFactor	(	TEXT("r.Lumen.ReSTIRGather.DownsampleFactor")	,
		GLumenReSTIRDownsampleFactor	,
		TEXT("Downsample factor from the main viewport to trace rays, create and resample reservoirs at. This is the main performance control for the tracing / resampling part of the algorithm.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherBilateralFilter()

FAutoConsoleVariableRef CVarLumenReSTIRGatherBilateralFilter	(	TEXT("r.Lumen.ReSTIRGather.BilateralFilter")	,
		GLumenReSTIRGatherBilateralFilter	,
		TEXT("Whether to do a bilateral filter as a last step in denoising Lumen ReSTIRGathers.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherBilateralFilterDepthWeightScale()

FAutoConsoleVariableRef CVarLumenReSTIRGatherBilateralFilterDepthWeightScale	(	TEXT("r.Lumen.ReSTIRGather.BilateralFilter.DepthWeightScale")	,
		GLumenReSTIRGatherBilateralFilterDepthWeightScale	,
		TEXT("Scales the depth weight of the bilateral filter")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale()

FAutoConsoleVariableRef CVarLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale	(	TEXT("r.Lumen.ReSTIRGather.BilateralFilter.NormalAngleThresholdScale")	,
		GLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale	,
		TEXT("Scales the Normal angle threshold of the bilateral filter")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherBilateralFilterNumSamples()

FAutoConsoleVariableRef CVarLumenReSTIRGatherBilateralFilterNumSamples	(	TEXT("r.Lumen.ReSTIRGather.BilateralFilter.NumSamples")	,
		GLumenReSTIRGatherBilateralFilterNumSamples	,
		TEXT("Number of bilateral filter samples.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherBilateralFilterSpatialKernelRadius()

FAutoConsoleVariableRef CVarLumenReSTIRGatherBilateralFilterSpatialKernelRadius	(	TEXT("r.Lumen.ReSTIRGather.BilateralFilter.SpatialKernelRadius")	,
		GLumenReSTIRGatherBilateralFilterSpatialKernelRadius	,
		TEXT("Spatial kernel radius, as a fraction of the viewport size")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold()

FAutoConsoleVariableRef CVarLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold	(	TEXT("r.Lumen.ReSTIRGather.BilateralFilter.StrongBlurVarianceThreshold")	,
		GLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold	,
		TEXT("Pixels whose variance from the spatial resolve filter are higher than this value get a stronger bilateral blur.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherHistoryDistanceThreshold()

FAutoConsoleVariableRef CVarLumenReSTIRGatherHistoryDistanceThreshold	(	TEXT("r.Lumen.ReSTIRGather.Temporal.DistanceThreshold")	,
		GLumenReSTIRGatherHistoryDistanceThreshold	,
		TEXT("Relative distance threshold needed to discard last frame's lighting results. Lower values reduce ghosting from characters when near a wall but increase flickering artifacts.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction()

FAutoConsoleVariableRef CVarLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction	(	TEXT("r.Lumen.ReSTIRGather.ShortRangeAO.MaxScreenTraceFraction")	,
		GLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction	,
		TEXT("Short range AO tracing distance, as a fraction of the screen size.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherTemporalFilter()

FAutoConsoleVariableRef CVarLumenReSTIRGatherTemporalFilter	(	TEXT("r.Lumen.ReSTIRGather.Temporal")	,
		GLumenReSTIRGatherTemporalFilter	,
		TEXT("Whether to use a temporal filter")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherTemporalMaxFramesAccumulated()

FAutoConsoleVariableRef CVarLumenReSTIRGatherTemporalMaxFramesAccumulated	(	TEXT("r.Lumen.ReSTIRGather.Temporal.MaxFramesAccumulated")	,
		GLumenReSTIRGatherTemporalMaxFramesAccumulated	,
		TEXT("Lower values cause the temporal filter to propagate lighting changes faster, but also increase flickering from noise.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRMaxRayIntensity()

FAutoConsoleVariableRef CVarLumenReSTIRMaxRayIntensity	(	TEXT("r.Lumen.ReSTIRGather.MaxRayIntensity")	,
		GLumenReSTIRMaxRayIntensity	,
		TEXT("Clamps the maximum ray lighting intensity (with PreExposure) to reduce fireflies.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRNumSamples()

FAutoConsoleVariableRef CVarLumenReSTIRNumSamples	(	TEXT("r.Lumen.ReSTIRGather.Upsample.NumSamples")	,
		GLumenReSTIRUpsampleNumSamples	,
		TEXT("Number of reservoir samples to take while upsampling. Only used when r.Lumen.ReSTIRGather.Upsample.Method is set to Spiral Pattern.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRNumSpatialSamples()

FAutoConsoleVariableRef CVarLumenReSTIRNumSpatialSamples	(	TEXT("r.Lumen.ReSTIRGather.SpatialResampling.NumSamples")	,
		GLumenReSTIRNumSpatialSamples	,
		TEXT("The number of spatial samples for each resampling pass.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRResamplingAngleThreshold()

FAutoConsoleVariableRef CVarLumenReSTIRResamplingAngleThreshold	(	TEXT("r.Lumen.ReSTIRGather.ResamplingAngleThreshold")	,
		GLumenReSTIRResamplingAngleThreshold	,
		TEXT("Largest angle between two reservoirs that will be allowed during reservoir resampling, in degrees")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRSpatialResampling()

FAutoConsoleVariableRef CVarLumenReSTIRSpatialResampling	(	TEXT("r.Lumen.ReSTIRGather.SpatialResampling")	,
		GLumenReSTIRSpatialResampling	,
		TEXT("Whether to use spatial resampling passes on the reservoirs")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRSpatialResamplingDepthErrorThreshold()

FAutoConsoleVariableRef CVarLumenReSTIRSpatialResamplingDepthErrorThreshold	(	TEXT("r.Lumen.ReSTIRGather.ResamplingDepthErrorThreshold")	,
		GLumenReSTIRResamplingDepthErrorThreshold	,
		TEXT("Largest depth error between two reservoirs that will be allowed during reservoir resampling")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRSpatialResamplingKernelRadius()

FAutoConsoleVariableRef CVarLumenReSTIRSpatialResamplingKernelRadius	(	TEXT("r.Lumen.ReSTIRGather.SpatialResampling.KernelRadius")	,
		GLumenReSTIRSpatialResamplingKernelRadius	,
		TEXT("Radius of the spatial resampling kernel as a fraction of the screen.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance()

FAutoConsoleVariableRef CVarLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance	(	TEXT("r.Lumen.ReSTIRGather.SpatialResampling.OcclusionScreenTraceDistance")	,
		GLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance	,
		TEXT("Length of occlusion screen traces used to validate the neighbor's reservoir hit position before reuse, to reduce leaking. As a fraction of the screen size.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRTemporalResampling()

FAutoConsoleVariableRef CVarLumenReSTIRTemporalResampling	(	TEXT("r.Lumen.ReSTIRGather.TemporalResampling")	,
		GLumenReSTIRTemporalResampling	,
		TEXT("Whether to do a temporal resampling pass on the reservoirs")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRTemporalResamplingResetHistory()

FAutoConsoleVariableRef CVarLumenReSTIRTemporalResamplingResetHistory	(	TEXT("r.Lumen.ReSTIRGather.TemporalResampling.ResetHistory")	,
		GLumenReSTIRTemporalResamplingResetHistory	,
		TEXT("")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRTemporalResamplingValidate()

FAutoConsoleVariableRef CVarLumenReSTIRTemporalResamplingValidate	(	TEXT("r.Lumen.ReSTIRGather.TemporalResampling.ValidateEveryNFrames")	,
		GLumenReSTIRValidateTemporalReservoirsEveryNFrames	,
		TEXT("Validate temporal reservoirs by re-tracing their rays and comparing hit positions and radiance every N frames. Used to reduce lag in lighting changes, but introduces noise.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRUpsampleKernelSize()

FAutoConsoleVariableRef CVarLumenReSTIRUpsampleKernelSize	(	TEXT("r.Lumen.ReSTIRGather.Upsample.KernelSize")	,
		GLumenReSTIRUpsampleKernelSize	,
		TEXT("Upsample kernel size, in reservoir texels")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRUpsampleMethod()

FAutoConsoleVariableRef CVarLumenReSTIRUpsampleMethod	(	TEXT("r.Lumen.ReSTIRGather.Upsample.Method")	,
		GLumenReSTIRUpsampleMethod	,
		TEXT("2 - Passthrough for debugging. Also effectively disables the bilateral filter as variance is not computed.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ CVarReSTIRTemporalResamplingHistoryDistanceThreshold()

FAutoConsoleVariableRef CVarReSTIRTemporalResamplingHistoryDistanceThreshold	(	TEXT("r.Lumen.ReSTIRGather.TemporalResampling.DistanceThreshold")	,
		GLumenReSTIRTemporalResamplingHistoryDistanceThreshold	,
		TEXT("")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ DispatchTemporalAccumulation()

void DispatchTemporalAccumulation	(	FRDGBuilder &	GraphBuilder,
		const FViewInfo &	View,
		const FSceneTextures &	SceneTextures,
		FLumenSceneFrameTemporaries &	FrameTemporaries,
		bool	bPropagateGlobalLightingChange,
		bool	bUseBilaterialFilter,
		FRDGTextureRef &	DiffuseIndirect,
		FRDGTextureRef &	RoughSpecularIndirect,
		FRDGTextureRef &	ResolveVariance,
		ERDGPassFlags	ComputePassFlags
	)

◆ DoesPlatformSupportLumenReSTIRGather()

bool DoesPlatformSupportLumenReSTIRGather ( EShaderPlatform Platform )

◆ GVarLumenReSTIRGatherShortRangeAO()

FAutoConsoleVariableRef GVarLumenReSTIRGatherShortRangeAO	(	TEXT("r.Lumen.ReSTIRGather.ShortRangeAO")	,
		GLumenReSTIRGatherShortRangeAmbientOcclusion	,
		TEXT("Whether to compute a short range, full resolution AO to add high frequency occlusion (contact shadows) which ReSTIR GI lacks due to spatial filtering.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ IMPLEMENT_GLOBAL_SHADER() [1/6]

IMPLEMENT_GLOBAL_SHADER	(	FBilateralFilterCS	,
		"/Engine/Private/Lumen/LumenReSTIRGather.usf"	,
		"BilateralFilterCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [2/6]

IMPLEMENT_GLOBAL_SHADER	(	FClearTemporalHistoryCS	,
		"/Engine/Private/Lumen/LumenReSTIRGather.usf"	,
		"ClearTemporalHistoryCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [3/6]

IMPLEMENT_GLOBAL_SHADER	(	FSpatialResamplingCS	,
		"/Engine/Private/Lumen/LumenReSTIRGather.usf"	,
		"SpatialResamplingCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [4/6]

IMPLEMENT_GLOBAL_SHADER	(	FTemporalAccumulationCS	,
		"/Engine/Private/Lumen/LumenReSTIRGather.usf"	,
		"TemporalAccumulationCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [5/6]

IMPLEMENT_GLOBAL_SHADER	(	FTemporalResamplingCS	,
		"/Engine/Private/Lumen/LumenReSTIRGather.usf"	,
		"TemporalResamplingCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [6/6]

IMPLEMENT_GLOBAL_SHADER	(	FUpsampleAndIntegrateCS	,
		"/Engine/Private/Lumen/LumenReSTIRGather.usf"	,
		"UpsampleAndIntegrateCS"	,
		SF_Compute
	)

Variable Documentation

◆ CVarLumenReSTIRGatherClearHistoryEveryFrame

FAutoConsoleVariableRef CVarLumenReSTIRGatherClearHistoryEveryFrame(TEXT("r.Lumen.ReSTIRGather.Temporal.ClearHistoryEveryFrame"), GLumenReSTIRGatherClearHistoryEveryFrame, TEXT("Whether to clear the history every frame for debugging"), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ReSTIRGather.Temporal.ClearHistoryEveryFrame")	,
		GLumenReSTIRGatherClearHistoryEveryFrame	,
		TEXT("Whether to clear the history every frame for debugging")	,
		ECVF_RenderThreadSafe
	)

◆ CVarLumenReSTIRGatherFixedJitterIndex

FAutoConsoleVariableRef CVarLumenReSTIRGatherFixedJitterIndex(TEXT("r.Lumen.ReSTIRGather.FixedJitterIndex"), GLumenReSTIRGatherFixedJitterIndex, TEXT("When 0 or larger, overrides the frame index with a constant for debugging"), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ReSTIRGather.FixedJitterIndex")	,
		GLumenReSTIRGatherFixedJitterIndex	,
		TEXT("When 0 or larger, overrides the frame index with a constant for debugging")	,
		ECVF_RenderThreadSafe
	)

◆ GLumenReSTIRDownsampleFactor

int32 GLumenReSTIRDownsampleFactor = 2

◆ GLumenReSTIRGatherBilateralFilter

int32 GLumenReSTIRGatherBilateralFilter = 1

◆ GLumenReSTIRGatherBilateralFilterDepthWeightScale

float GLumenReSTIRGatherBilateralFilterDepthWeightScale = 10000.0f

◆ GLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale

float GLumenReSTIRGatherBilateralFilterNormalAngleThresholdScale = .2f

◆ GLumenReSTIRGatherBilateralFilterNumSamples

int32 GLumenReSTIRGatherBilateralFilterNumSamples = 8

◆ GLumenReSTIRGatherBilateralFilterSpatialKernelRadius

float GLumenReSTIRGatherBilateralFilterSpatialKernelRadius = .002f

◆ GLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold

float GLumenReSTIRGatherBilateralFilterStrongBlurVarianceThreshold = .5f

◆ GLumenReSTIRGatherClearHistoryEveryFrame

int32 GLumenReSTIRGatherClearHistoryEveryFrame = 0

◆ GLumenReSTIRGatherFixedJitterIndex

int32 GLumenReSTIRGatherFixedJitterIndex = -1

◆ GLumenReSTIRGatherHistoryDistanceThreshold

float GLumenReSTIRGatherHistoryDistanceThreshold = .005f

◆ GLumenReSTIRGatherShortRangeAmbientOcclusion

int32 GLumenReSTIRGatherShortRangeAmbientOcclusion = 1

◆ GLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction

float GLumenReSTIRGatherShortRangeAOMaxScreenTraceFraction = .02f

◆ GLumenReSTIRGatherTemporalFilter

int32 GLumenReSTIRGatherTemporalFilter = 1

◆ GLumenReSTIRGatherTemporalMaxFramesAccumulated

float GLumenReSTIRGatherTemporalMaxFramesAccumulated = 10.0f

◆ GLumenReSTIRMaxRayIntensity

float GLumenReSTIRMaxRayIntensity = 100

◆ GLumenReSTIRNumSpatialResamplingPasses

int32 GLumenReSTIRNumSpatialResamplingPasses = 2

◆ GLumenReSTIRNumSpatialSamples

int32 GLumenReSTIRNumSpatialSamples = 4

◆ GLumenReSTIRResamplingAngleThreshold

float GLumenReSTIRResamplingAngleThreshold = 25.0f

◆ GLumenReSTIRResamplingDepthErrorThreshold

float GLumenReSTIRResamplingDepthErrorThreshold = .01f

◆ GLumenReSTIRSpatialResampling

int32 GLumenReSTIRSpatialResampling = 1

◆ GLumenReSTIRSpatialResamplingKernelRadius

float GLumenReSTIRSpatialResamplingKernelRadius = .05f

◆ GLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance

float GLumenReSTIRSpatialResamplingOcclusionScreenTraceDistance = .2f

◆ GLumenReSTIRTemporalResampling

int32 GLumenReSTIRTemporalResampling = 1

◆ GLumenReSTIRTemporalResamplingHistoryDistanceThreshold

float GLumenReSTIRTemporalResamplingHistoryDistanceThreshold = .005f

◆ GLumenReSTIRTemporalResamplingResetHistory

int32 GLumenReSTIRTemporalResamplingResetHistory = 0

◆ GLumenReSTIRUpsampleKernelSize

float GLumenReSTIRUpsampleKernelSize = 3.0f

◆ GLumenReSTIRUpsampleMethod

int32 GLumenReSTIRUpsampleMethod = 1

◆ GLumenReSTIRUpsampleNumSamples

int32 GLumenReSTIRUpsampleNumSamples = 16

◆ GLumenReSTIRValidateTemporalReservoirsEveryNFrames

int32 GLumenReSTIRValidateTemporalReservoirsEveryNFrames = 0

Classes

Namespaces

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