#include "LumenScreenProbeGather.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 "HairStrands/HairStrandsData.h"

Classes
class	FClearTracesCS

class	FScreenProbeTraceScreenTexturesCS

class	FScreenProbeCompactTracesCS

class	FSetupCompactedTracesIndirectArgsCS

class	FScreenProbeTraceMeshSDFsCS

class	FScreenProbeTraceVoxelsCS

class	FScreenProbeSetupVisualizeTracesCS

Enumerations
enum class	ECompactedTracingIndirectArgs { NumTracesDiv64 = 0 * sizeof(FRHIDispatchIndirectParameters) , NumTracesDiv32 = 1 * sizeof(FRHIDispatchIndirectParameters) , NumLightSampleTracesDiv64 = 2 * sizeof(FRHIDispatchIndirectParameters) , NumLightSampleTracesDiv32 = 3 * sizeof(FRHIDispatchIndirectParameters) , MAX = 4 }

Functions
FAutoConsoleVariableRef	GVarLumenScreenProbeGatherScreenTraces (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces"), GLumenScreenProbeGatherScreenTraces, TEXT("Whether to trace against the screen before falling back to other tracing methods."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherHierarchicalScreenTraces (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal"), GLumenScreenProbeGatherHierarchicalScreenTraces, TEXT("Whether to use HZB tracing for SSGI instead of fixed step count intersection. HZB tracing is much more accurate, in particular not missing thin features, but is about ~3x slower."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.FullResDepth"), GLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth, TEXT("Whether the HZB traversal should go all the way down to the full resolution depth, which is more accurate but adds incoherency to the inner loop."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.SkipFoliageHits"), GLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits, TEXT("Whether to allow screen traces to hit Subsurface and TwoSided Foliage shading models. Can be used to work around aliasing from high frequency grass geometry."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.MaxIterations"), GLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations, TEXT("Max iterations for HZB tracing."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherRelativeDepthThickness (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.RelativeDepthThickness"), GLumenScreenProbeGatherRelativeDepthThickness, TEXT("Determines depth thickness of objects hit by HZB tracing, as a relative depth threshold."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherHistoryDepthTestRelativeThickness (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.HistoryDepthTestRelativeThickness"), GLumenScreenProbeGatherHistoryDepthTestRelativeThickness, TEXT("Distance between HZB trace hit and previous frame scene depth from which to allow hits, as a relative depth threshold."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.NumThicknessStepsToDetermineCertainty"), GLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty, TEXT("Number of linear search steps to determine if a hit feature is thin and should be ignored."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherVisualizeTraces (TEXT("r.Lumen.ScreenProbeGather.VisualizeTraces"), GLumenScreenProbeGatherVisualizeTraces, TEXT("Whether to visualize traces for the center screen probe, useful for debugging"), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherVisualizeTracesFreeze (TEXT("r.Lumen.ScreenProbeGather.VisualizeTracesFreeze"), GLumenScreenProbeGatherVisualizeTracesFreeze, TEXT("Whether to freeze updating the visualize trace data. Note that no changes to cvars or shaders will propagate until unfrozen."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherHairStrands_VoxelTrace (TEXT("r.Lumen.ScreenProbeGather.HairStrands.VoxelTrace"), GLumenScreenProbeGatherHairStrands_VoxelTrace, TEXT("Whether to trace against hair voxel structure for hair casting shadow onto opaques."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	GVarLumenScreenProbeGatherHairStrands_ScreenTrace (TEXT("r.Lumen.ScreenProbeGather.HairStrands.ScreenTrace"), GLumenScreenProbeGatherHairStrands_ScreenTrace, TEXT("Whether to trace against hair depth for hair casting shadow onto opaques."), ECVF_Scalability\|ECVF_RenderThreadSafe)

FAutoConsoleVariableRef	CVarLumenScreenProbeGatherScreenTraceMinimumOccupancy (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.MinimumOccupancy"), GLumenScreenProbeGatherScreenTracesMinimumOccupancy, TEXT("Minimum number of threads still tracing before aborting the trace. Can be used for scalability to abandon traces that have a disproportionate cost."), ECVF_Scalability\|ECVF_RenderThreadSafe)

bool	SupportsHairScreenTraces ()

	IMPLEMENT_GLOBAL_SHADER (FClearTracesCS, "/Engine/Private/Lumen/LumenScreenProbeTracing.usf", "ClearTracesCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FScreenProbeTraceScreenTexturesCS, "/Engine/Private/Lumen/LumenScreenProbeTracing.usf", "ScreenProbeTraceScreenTexturesCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FScreenProbeCompactTracesCS, "/Engine/Private/Lumen/LumenScreenProbeTracing.usf", "ScreenProbeCompactTracesCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FSetupCompactedTracesIndirectArgsCS, "/Engine/Private/Lumen/LumenScreenProbeTracing.usf", "SetupCompactedTracesIndirectArgsCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FScreenProbeTraceMeshSDFsCS, "/Engine/Private/Lumen/LumenScreenProbeTracing.usf", "ScreenProbeTraceMeshSDFsCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FScreenProbeTraceVoxelsCS, "/Engine/Private/Lumen/LumenScreenProbeTracing.usf", "ScreenProbeTraceVoxelsCS", SF_Compute)

	IMPLEMENT_GLOBAL_SHADER (FScreenProbeSetupVisualizeTracesCS, "/Engine/Private/Lumen/LumenScreenProbeTracing.usf", "ScreenProbeSetupVisualizeTraces", SF_Compute)

void	SetupVisualizeTraces (FRDGBuilder &GraphBuilder, const FSceneTextures &SceneTextures, const FScene *Scene, const FViewInfo &View, const FScreenProbeParameters &ScreenProbeParameters, ERDGPassFlags ComputePassFlags)

void	GetScreenProbeVisualizeTracesBuffer (TRefCountPtr< FRDGPooledBuffer > &VisualizeTracesData)

void	TraceScreenProbes (FRDGBuilder &GraphBuilder, const FScene *Scene, const FViewInfo &View, const FLumenSceneFrameTemporaries &FrameTemporaries, bool bTraceMeshObjects, const FSceneTextures &SceneTextures, FRDGTextureRef LightingChannelsTexture, const LumenRadianceCache::FRadianceCacheInterpolationParameters &RadianceCacheParameters, FScreenProbeParameters &ScreenProbeParameters, FLumenMeshSDFGridParameters &MeshSDFGridParameters, ERDGPassFlags ComputePassFlags)

Variables
int32	GLumenScreenProbeGatherScreenTraces = 1

int32	GLumenScreenProbeGatherHierarchicalScreenTraces = 1

int32	GLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth = 1

int32	GLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits = 1

int32	GLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations = 50

float	GLumenScreenProbeGatherRelativeDepthThickness = .02f

float	GLumenScreenProbeGatherHistoryDepthTestRelativeThickness = 0.005f

int32	GLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty = 4

int32	GLumenScreenProbeGatherVisualizeTraces = 0

int32	GLumenScreenProbeGatherVisualizeTracesFreeze = 0

int32	GLumenScreenProbeGatherHairStrands_VoxelTrace = 1

int32	GLumenScreenProbeGatherHairStrands_ScreenTrace = 0

int32	GLumenScreenProbeGatherScreenTracesMinimumOccupancy = 0

TRefCountPtr< FRDGPooledBuffer >	GVisualizeTracesData

Enumeration Type Documentation

◆ ECompactedTracingIndirectArgs

enum class ECompactedTracingIndirectArgs

strong

Enumerator
NumTracesDiv64
NumTracesDiv32
NumLightSampleTracesDiv64
NumLightSampleTracesDiv32
MAX

Function Documentation

◆ CVarLumenScreenProbeGatherScreenTraceMinimumOccupancy()

FAutoConsoleVariableRef CVarLumenScreenProbeGatherScreenTraceMinimumOccupancy	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.MinimumOccupancy")	,
		GLumenScreenProbeGatherScreenTracesMinimumOccupancy	,
		TEXT("Minimum number of threads still tracing before aborting the trace. Can be used for scalability to abandon traces that have a disproportionate cost.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GetScreenProbeVisualizeTracesBuffer()

void GetScreenProbeVisualizeTracesBuffer ( TRefCountPtr< FRDGPooledBuffer > & VisualizeTracesData )

◆ GVarLumenScreenProbeGatherHairStrands_ScreenTrace()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherHairStrands_ScreenTrace	(	TEXT("r.Lumen.ScreenProbeGather.HairStrands.ScreenTrace")	,
		GLumenScreenProbeGatherHairStrands_ScreenTrace	,
		TEXT("Whether to trace against hair depth for hair casting shadow onto opaques.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherHairStrands_VoxelTrace()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherHairStrands_VoxelTrace	(	TEXT("r.Lumen.ScreenProbeGather.HairStrands.VoxelTrace")	,
		GLumenScreenProbeGatherHairStrands_VoxelTrace	,
		TEXT("Whether to trace against hair voxel structure for hair casting shadow onto opaques.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherHierarchicalScreenTraces()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherHierarchicalScreenTraces	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal")	,
		GLumenScreenProbeGatherHierarchicalScreenTraces	,
		TEXT("Whether to use HZB tracing for SSGI instead of fixed step count intersection. HZB tracing is much more accurate, in particular not missing thin features, but is about ~3x slower.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.FullResDepth")	,
		GLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth	,
		TEXT("Whether the HZB traversal should go all the way down to the full resolution depth, which is more accurate but adds incoherency to the inner loop.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.MaxIterations")	,
		GLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations	,
		TEXT("Max iterations for HZB tracing.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.SkipFoliageHits")	,
		GLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits	,
		TEXT("Whether to allow screen traces to hit Subsurface and TwoSided Foliage shading models. Can be used to work around aliasing from high frequency grass geometry.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherHistoryDepthTestRelativeThickness()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherHistoryDepthTestRelativeThickness	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.HistoryDepthTestRelativeThickness")	,
		GLumenScreenProbeGatherHistoryDepthTestRelativeThickness	,
		TEXT("Distance between HZB trace hit and previous frame scene depth from which to allow hits, as a relative depth threshold.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.NumThicknessStepsToDetermineCertainty")	,
		GLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty	,
		TEXT("Number of linear search steps to determine if a hit feature is thin and should be ignored.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherRelativeDepthThickness()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherRelativeDepthThickness	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.RelativeDepthThickness")	,
		GLumenScreenProbeGatherRelativeDepthThickness	,
		TEXT("Determines depth thickness of objects hit by HZB tracing, as a relative depth threshold.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherScreenTraces()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherScreenTraces	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces")	,
		GLumenScreenProbeGatherScreenTraces	,
		TEXT("Whether to trace against the screen before falling back to other tracing methods.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherVisualizeTraces()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherVisualizeTraces	(	TEXT("r.Lumen.ScreenProbeGather.VisualizeTraces")	,
		GLumenScreenProbeGatherVisualizeTraces	,
		TEXT("Whether to visualize traces for the center screen probe, useful for debugging")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ GVarLumenScreenProbeGatherVisualizeTracesFreeze()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherVisualizeTracesFreeze	(	TEXT("r.Lumen.ScreenProbeGather.VisualizeTracesFreeze")	,
		GLumenScreenProbeGatherVisualizeTracesFreeze	,
		TEXT("Whether to freeze updating the visualize trace data. Note that no changes to cvars or shaders will propagate until unfrozen.")	,
		ECVF_Scalability\|	ECVF_RenderThreadSafe
	)

◆ IMPLEMENT_GLOBAL_SHADER() [1/7]

IMPLEMENT_GLOBAL_SHADER	(	FClearTracesCS	,
		"/Engine/Private/Lumen/LumenScreenProbeTracing.usf"	,
		"ClearTracesCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [2/7]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeCompactTracesCS	,
		"/Engine/Private/Lumen/LumenScreenProbeTracing.usf"	,
		"ScreenProbeCompactTracesCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [3/7]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeSetupVisualizeTracesCS	,
		"/Engine/Private/Lumen/LumenScreenProbeTracing.usf"	,
		"ScreenProbeSetupVisualizeTraces"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [4/7]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeTraceMeshSDFsCS	,
		"/Engine/Private/Lumen/LumenScreenProbeTracing.usf"	,
		"ScreenProbeTraceMeshSDFsCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [5/7]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeTraceScreenTexturesCS	,
		"/Engine/Private/Lumen/LumenScreenProbeTracing.usf"	,
		"ScreenProbeTraceScreenTexturesCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [6/7]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeTraceVoxelsCS	,
		"/Engine/Private/Lumen/LumenScreenProbeTracing.usf"	,
		"ScreenProbeTraceVoxelsCS"	,
		SF_Compute
	)

◆ IMPLEMENT_GLOBAL_SHADER() [7/7]

IMPLEMENT_GLOBAL_SHADER	(	FSetupCompactedTracesIndirectArgsCS	,
		"/Engine/Private/Lumen/LumenScreenProbeTracing.usf"	,
		"SetupCompactedTracesIndirectArgsCS"	,
		SF_Compute
	)

◆ SetupVisualizeTraces()

void SetupVisualizeTraces	(	FRDGBuilder &	GraphBuilder,
		const FSceneTextures &	SceneTextures,
		const FScene *	Scene,
		const FViewInfo &	View,
		const FScreenProbeParameters &	ScreenProbeParameters,
		ERDGPassFlags	ComputePassFlags
	)

◆ SupportsHairScreenTraces()

bool SupportsHairScreenTraces ( )

◆ TraceScreenProbes()

void TraceScreenProbes	(	FRDGBuilder &	GraphBuilder,
		const FScene *	Scene,
		const FViewInfo &	View,
		const FLumenSceneFrameTemporaries &	FrameTemporaries,
		bool	bTraceMeshObjects,
		const FSceneTextures &	SceneTextures,
		FRDGTextureRef	LightingChannelsTexture,
		const LumenRadianceCache::FRadianceCacheInterpolationParameters &	RadianceCacheParameters,
		FScreenProbeParameters &	ScreenProbeParameters,
		FLumenMeshSDFGridParameters &	MeshSDFGridParameters,
		ERDGPassFlags	ComputePassFlags
	)

Variable Documentation

◆ GLumenScreenProbeGatherHairStrands_ScreenTrace

int32 GLumenScreenProbeGatherHairStrands_ScreenTrace = 0

◆ GLumenScreenProbeGatherHairStrands_VoxelTrace

int32 GLumenScreenProbeGatherHairStrands_VoxelTrace = 1

◆ GLumenScreenProbeGatherHierarchicalScreenTraces

int32 GLumenScreenProbeGatherHierarchicalScreenTraces = 1

◆ GLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth

int32 GLumenScreenProbeGatherHierarchicalScreenTracesFullResDepth = 1

◆ GLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations

int32 GLumenScreenProbeGatherHierarchicalScreenTracesMaxIterations = 50

◆ GLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits

int32 GLumenScreenProbeGatherHierarchicalScreenTracesSkipFoliageHits = 1

◆ GLumenScreenProbeGatherHistoryDepthTestRelativeThickness

float GLumenScreenProbeGatherHistoryDepthTestRelativeThickness = 0.005f

◆ GLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty

int32 GLumenScreenProbeGatherNumThicknessStepsToDetermineCertainty = 4

◆ GLumenScreenProbeGatherRelativeDepthThickness

float GLumenScreenProbeGatherRelativeDepthThickness = .02f

◆ GLumenScreenProbeGatherScreenTraces

int32 GLumenScreenProbeGatherScreenTraces = 1

◆ GLumenScreenProbeGatherScreenTracesMinimumOccupancy

int32 GLumenScreenProbeGatherScreenTracesMinimumOccupancy = 0

◆ GLumenScreenProbeGatherVisualizeTraces

int32 GLumenScreenProbeGatherVisualizeTraces = 0

◆ GLumenScreenProbeGatherVisualizeTracesFreeze

int32 GLumenScreenProbeGatherVisualizeTracesFreeze = 0

◆ GVisualizeTracesData

TRefCountPtr<FRDGPooledBuffer> GVisualizeTracesData

Classes

Enumerations

Functions

Variables