LumenScreenProbeGather.cpp File Reference

#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 "Substrate/Substrate.h"
#include "LumenReflections.h"
#include "LumenShortRangeAO.h"
#include "ShaderPrintParameters.h"
#include "../StochasticLighting/StochasticLighting.h"

Classes
class	FScreenProbeDownsampleDepthUniformCS
class	FScreenProbeAdaptivePlacementMarkCS
class	FScreenProbeAdaptivePlacementSpawnCS
class	FSetupAdaptiveProbeIndirectArgsCS
class	FMarkRadianceProbesUsedByScreenProbesCS
class	FMarkRadianceProbesUsedByHairStrandsCS
class	FInitScreenProbeTileIndirectArgsCS
class	FScreenProbeTileClassificationBuildListsCS
class	FScreenProbeIntegrateClearUnusedTileDataCS
class	FScreenProbeIntegrateCS
class	FScreenProbeTemporalReprojectionCS
class	FLumenScreenProbeSubstrateDebugPass
class	FScreenProbeGatherDebugCS

Namespaces
namespace	LumenScreenProbeGather
namespace	LumenScreenProbeGatherRadianceCache

Functions
FAutoConsoleVariableRef	GVarLumenScreenProbeGather (TEXT("r.Lumen.ScreenProbeGather"), GLumenScreenProbeGather, TEXT("Whether to use the Screen Probe Final Gather"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeGatherTraceMeshSDFs (TEXT("r.Lumen.ScreenProbeGather.TraceMeshSDFs"), GLumenGatherCvars.TraceMeshSDFs, TEXT("Whether to trace against Mesh Signed Distance fields for Lumen's Screen Probe Gather."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarAdaptiveProbeAllocationFraction (TEXT("r.Lumen.ScreenProbeGather.AdaptiveProbeAllocationFraction"), GLumenScreenProbeGatherAdaptiveProbeAllocationFraction, TEXT("Fraction of uniform probes to allow for adaptive probe placement."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeGatherReferenceMode (TEXT("r.Lumen.ScreenProbeGather.ReferenceMode"), GLumenScreenProbeGatherReferenceMode, TEXT("When enabled, traces 1024 uniform rays per probe with no filtering, Importance Sampling or Radiance Caching."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeTracingOctahedronResolution (TEXT("r.Lumen.ScreenProbeGather.TracingOctahedronResolution"), GLumenScreenProbeTracingOctahedronResolution, TEXT("Resolution of the tracing octahedron. Determines how many traces are done per probe."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeGatherOctahedronResolutionScale (TEXT("r.Lumen.ScreenProbeGather.GatherOctahedronResolutionScale"), GLumenScreenProbeGatherOctahedronResolutionScale, TEXT("Resolution that probe filtering and integration will happen at, as a scale of TracingOctahedronResolution"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeDownsampleFactor (TEXT("r.Lumen.ScreenProbeGather.DownsampleFactor"), GLumenScreenProbeDownsampleFactor, TEXT("Pixel size of the screen tile that a screen probe will be placed on."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeFullResolutionJitterWidth (TEXT("r.Lumen.ScreenProbeGather.FullResolutionJitterWidth"), GLumenScreenProbeFullResolutionJitterWidth, TEXT("Size of the full resolution jitter applied to Screen Probe upsampling, as a fraction of a screen tile. A width of 1 results in jittering by DownsampleFactor number of pixels."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeIntegrationTileClassification (TEXT("r.Lumen.ScreenProbeGather.IntegrationTileClassification"), GLumenScreenProbeIntegrationTileClassification, TEXT("Whether to use tile classification during diffuse integration. Tile Classification splits compute dispatches by VGPRs for better occupancy, but can introduce errors if implemented incorrectly."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeSupportBackfaceDiffuse (TEXT("r.Lumen.ScreenProbeGather.TwoSidedFoliageBackfaceDiffuse"), GLumenScreenProbeSupportTwoSidedFoliageBackfaceDiffuse, TEXT("Whether to gather lighting along the backface for the Two Sided Foliage shading model, which adds some GPU cost. The final lighting is then DiffuseColor * FrontfaceLighting + SubsurfaceColor * BackfaceLighting. When disabled, SubsurfaceColor will simply be added to DiffuseColor instead."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeDiffuseIntegralMethod (TEXT("r.Lumen.ScreenProbeGather.DiffuseIntegralMethod"), GLumenScreenProbeDiffuseIntegralMethod, TEXT("Preintegrated for probe (see IrradianceFormat) = 0, Importance Sample BRDF = 1, Numerical Integral Reference = 2"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeMaterialAO (TEXT("r.Lumen.ScreenProbeGather.MaterialAO"), GLumenScreenProbeMaterialAO, TEXT("Whether to apply Material Ambient Occlusion or Material Bent Normal to Lumen GI."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeTemporalFilter (TEXT("r.Lumen.ScreenProbeGather.Temporal"), GLumenScreenProbeTemporalFilter, TEXT("Whether to use a temporal filter"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeFractionOfLightingMovingForFastUpdateMode (TEXT("r.Lumen.ScreenProbeGather.Temporal.FractionOfLightingMovingForFastUpdateMode"), GLumenScreenProbeFractionOfLightingMovingForFastUpdateMode, TEXT(""), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeTemporalMaxFastUpdateModeAmount (TEXT("r.Lumen.ScreenProbeGather.Temporal.MaxFastUpdateModeAmount"), GLumenScreenProbeTemporalMaxFastUpdateModeAmount, TEXT("Maximum amount of fast-responding temporal filter to use when traces hit a moving object. Values closer to 1 cause more noise, but also faster reaction to scene changes."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp (TEXT("r.Lumen.ScreenProbeGather.Temporal.FastUpdateModeUseNeighborhoodClamp"), GLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp, TEXT("Whether to clamp history values to the current frame's screen space neighborhood, in areas around moving objects."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving (TEXT("r.Lumen.ScreenProbeGather.Temporal.RelativeSpeedDifferenceToConsiderLightingMoving"), GLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving, TEXT(""), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeTemporalMaxFramesAccumulated (TEXT("r.Lumen.ScreenProbeGather.Temporal.MaxFramesAccumulated"), GLumenScreenProbeTemporalMaxFramesAccumulated, TEXT("Lower values cause the temporal filter to propagate lighting changes faster, but also increase flickering from noise."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeTemporalHistoryNormalThreshold (TEXT("r.Lumen.ScreenProbeGather.Temporal.NormalThreshold"), GLumenScreenProbeTemporalHistoryNormalThreshold, TEXT("Maximum angle that the history texel's normal can be from the current pixel to accept it's history lighting, in degrees."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback (TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.ThicknessScaleWhenNoFallback"), GLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback, TEXT("Larger scales effectively treat depth buffer surfaces as thicker for screen traces when there is no Distance Field present to resume the occluded ray."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeFilter (TEXT("r.Lumen.ScreenProbeGather.SpatialFilterProbes"), GLumenScreenProbeSpatialFilter, TEXT("Whether to spatially filter probe traces to reduce noise."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeTemporalFilter (TEXT("r.Lumen.ScreenProbeGather.TemporalFilterProbes"), GLumenScreenProbeTemporalFilterProbes, TEXT("Whether to temporally filter probe traces to reduce noise."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeExtraAmbientOcclusion (TEXT("r.Lumen.ScreenProbeGather.ExtraAmbientOcclusion"), GLumenScreenProbeExtraAmbientOcclusion, TEXT("1: Extra AO on"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace (TEXT("r.Lumen.ScreenProbeGather.ExtraAmbientOcclusion.MaxDistanceWorldSpace"), GLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace, TEXT("Maximum distance from the receiver surface that another surface in the world should cause ambient occlusion."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeExtraAmbientOcclusionExponent (TEXT("r.Lumen.ScreenProbeGather.ExtraAmbientOcclusion.Exponent"), GLumenScreenProbeExtraAmbientOcclusionExponent, TEXT("Exponent applied to the distance fraction of an occluder to calculate its occlusion. Values smaller than one reduce the occlusion of nearby objects, while values larger than one increase the occlusion of nearby objects."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenSpaceShortRangeAO (TEXT("r.Lumen.ScreenProbeGather.ShortRangeAO"), GLumenShortRangeAmbientOcclusion, TEXT("Whether to compute a short range, full resolution AO to add high frequency occlusion (contact shadows) which Screen Probes lack due to downsampling."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeUseJitter (TEXT("r.Lumen.ScreenProbeGather.FixedJitterIndex"), GLumenScreenProbeFixedJitterIndex, TEXT("If zero or greater, overrides the temporal jitter index with a fixed index. Useful for debugging and inspecting sampling patterns."), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarRadianceCache (TEXT("r.Lumen.ScreenProbeGather.RadianceCache"), GLumenRadianceCache, TEXT("Whether to enable the Persistent world space Radiance Cache"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeIrradianceFormat (TEXT("r.Lumen.ScreenProbeGather.IrradianceFormat"), GLumenScreenProbeIrradianceFormat, TEXT("1 - Octahedral probe. Faster, but reverts to SH3 when ShortRangeAO.ApplyDuringIntegration is enabled together with BentNormal"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarLumenScreenProbeStochasticInterpolation (TEXT("r.Lumen.ScreenProbeGather.StochasticInterpolation"), GLumenScreenProbeStochasticInterpolation, TEXT("Where to interpolate screen probes stochastically (1 sample) or bilinearly (4 samples)"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	GVarLumenScreenProbeTileDebugMode (TEXT("r.Lumen.ScreenProbeGather.TileDebugMode"), GLumenScreenProbeTileDebugMode, TEXT("Display Lumen screen probe tile classification."), ECVF_Scalability|ECVF_RenderThreadSafe)
bool	SupportsHairScreenTraces ()
uint32	LumenScreenProbeGather::GetStateFrameIndex (const FSceneViewState *ViewState)
bool	LumenScreenProbeGather::UseShortRangeAmbientOcclusion (const FEngineShowFlags &ShowFlags)
uint32	LumenScreenProbeGather::GetRequestedIntegrateDownsampleFactor ()
uint32	LumenScreenProbeGather::GetIntegrateDownsampleFactor (const FViewInfo &View)
bool	LumenScreenProbeGather::IsUsingDownsampledDepthAndNormal (const FViewInfo &View)
int32	LumenScreenProbeGather::GetTracingOctahedronResolution (const FViewInfo &View)
int32	LumenScreenProbeGather::GetGatherOctahedronResolution (int32 TracingOctahedronResolution)
int32	LumenScreenProbeGather::GetScreenDownsampleFactor (const FViewInfo &View, const FSceneTextures &SceneTextures)
bool	LumenScreenProbeGather::UseProbeSpatialFilter ()
bool	LumenScreenProbeGather::UseProbeTemporalFilter ()
int32	LumenScreenProbeGather::GetDiffuseIntegralMethod ()
EScreenProbeIrradianceFormat	LumenScreenProbeGather::GetScreenProbeIrradianceFormat (const FEngineShowFlags &ShowFlags)
bool	LumenScreenProbeGather::UseScreenProbeExtraAO ()
float	LumenScreenProbeGather::GetScreenProbeFullResolutionJitterWidth (const FViewInfo &View)
bool	LumenScreenProbeGather::UseWaveOps (EShaderPlatform ShaderPlatform)
FIntPoint	LumenScreenProbeGather::GetNumSamplesPerUniformProbe2D (uint32 NumSamplesPerUniformProbe)
FAutoConsoleVariableRef	CVarRadianceCacheProbeResolution (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ProbeResolution"), GRadianceCacheProbeResolution, TEXT("Resolution of the probe's 2d radiance layout. The number of rays traced for the probe will be ProbeResolution ^ 2"), ECVF_Scalability|ECVF_RenderThreadSafe)
FAutoConsoleVariableRef	CVarRadianceCacheNumMipmaps (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.NumMipmaps"), GRadianceCacheNumMipmaps, TEXT("Number of radiance cache mipmaps."), ECVF_Scalability|ECVF_RenderThreadSafe)
int32	LumenScreenProbeGatherRadianceCache::GetNumClipmaps ()
int32	LumenScreenProbeGatherRadianceCache::GetClipmapGridResolution ()
int32	LumenScreenProbeGatherRadianceCache::GetProbeResolution ()
int32	LumenScreenProbeGatherRadianceCache::GetFinalProbeResolution ()
FIntVector	LumenScreenProbeGatherRadianceCache::GetProbeIndirectionTextureSize ()
int32	LumenScreenProbeGatherRadianceCache::GetProbeAtlasResolutionInProbes ()
FIntPoint	LumenScreenProbeGatherRadianceCache::GetProbeAtlasTextureSize ()
FIntPoint	LumenScreenProbeGatherRadianceCache::GetFinalRadianceAtlasTextureSize ()
int32	LumenScreenProbeGatherRadianceCache::GetMaxNumProbes ()
LumenRadianceCache::FRadianceCacheInputs	LumenScreenProbeGatherRadianceCache::SetupRadianceCacheInputs (const FViewInfo &View)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeDownsampleDepthUniformCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "ScreenProbeDownsampleDepthUniformCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeAdaptivePlacementMarkCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "ScreenProbeAdaptivePlacementMarkCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeAdaptivePlacementSpawnCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "ScreenProbeAdaptivePlacementSpawnCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FSetupAdaptiveProbeIndirectArgsCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "SetupAdaptiveProbeIndirectArgsCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FMarkRadianceProbesUsedByScreenProbesCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "MarkRadianceProbesUsedByScreenProbesCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FMarkRadianceProbesUsedByHairStrandsCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "MarkRadianceProbesUsedByHairStrandsCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FInitScreenProbeTileIndirectArgsCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "InitScreenProbeTileIndirectArgsCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeTileClassificationBuildListsCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "ScreenProbeTileClassificationBuildListsCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeIntegrateClearUnusedTileDataCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "ScreenProbeIntegrateClearUnusedTileDataCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeIntegrateCS, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "ScreenProbeIntegrateCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeTemporalReprojectionCS, "/Engine/Private/Lumen/LumenScreenProbeGatherTemporal.usf", "ScreenProbeTemporalReprojectionCS", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FLumenScreenProbeSubstrateDebugPass, "/Engine/Private/Lumen/LumenScreenProbeGather.usf", "ScreenProbeDebugMain", SF_Compute)
	IMPLEMENT_GLOBAL_SHADER (FScreenProbeGatherDebugCS, "/Engine/Private/Lumen/LumenScreenProbeDebug.usf", "ScreenProbeGatherDebugCS", SF_Compute)
void	AddLumenScreenProbeDebugPass (FRDGBuilder &GraphBuilder, FViewInfo &View, const FIntPoint &ViewportIntegrateTileDimensions, const FIntPoint &ViewportIntegrateTileDimensionsWithOverflow, FRDGBufferRef IntegrateTileData, FRDGBufferRef IntegrateIndirectArgs)
const TCHAR *	GetClassificationModeString (EScreenProbeIntegrateTileClassification Mode)
void	InterpolateAndIntegrate (FRDGBuilder &GraphBuilder, const FSceneTextures &SceneTextures, FViewInfo &View, const FLumenSceneFrameTemporaries &FrameTemporaries, const FScreenProbeParameters &ScreenProbeParameters, const FScreenProbeGatherParameters &GatherParameters, FScreenProbeIntegrateParameters &IntegrateParameters, const FLumenScreenSpaceBentNormalParameters &ScreenSpaceBentNormalParameters, EReflectionsMethod ReflectionsMethod, FRDGTextureRef DiffuseIndirect, FRDGTextureRef LightIsMoving, FRDGTextureRef BackfaceDiffuseIndirect, FRDGTextureRef RoughSpecularIndirect, ERDGPassFlags ComputePassFlags)
void	UpdateHistoryScreenProbeGather (FRDGBuilder &GraphBuilder, const FViewInfo &View, const FSceneTextures &SceneTextures, FLumenSceneFrameTemporaries &FrameTemporaries, const FScreenProbeGatherCommonParameters &ScreenProbeGatherCommonParameters, const FScreenProbeIntegrateParameters &IntegrateParameters, FLumenScreenSpaceBentNormalParameters &ScreenSpaceBentNormalParameters, bool bPropagateGlobalLightingChange, FRDGTextureRef &DiffuseIndirect, FRDGTextureRef LightIsMoving, FRDGTextureRef &BackfaceDiffuseIndirect, FRDGTextureRef &RoughSpecularIndirect, ERDGPassFlags ComputePassFlags)
	DECLARE_GPU_STAT (LumenScreenProbeGather)

Variables
FLumenGatherCvarState	GLumenGatherCvars
int32	GLumenScreenProbeGather = 1
float	GLumenScreenProbeGatherAdaptiveProbeAllocationFraction = .5f
int32	GLumenScreenProbeGatherReferenceMode = 0
int32	GLumenScreenProbeTracingOctahedronResolution = 8
float	GLumenScreenProbeGatherOctahedronResolutionScale = 1.0f
int32	GLumenScreenProbeDownsampleFactor = 16
float	GLumenScreenProbeFullResolutionJitterWidth = 1
int32	GLumenScreenProbeIntegrationTileClassification = 1
int32	GLumenScreenProbeSupportTwoSidedFoliageBackfaceDiffuse = 1
int32	GLumenScreenProbeDiffuseIntegralMethod = 0
int32	GLumenScreenProbeMaterialAO = 1
TAutoConsoleVariable< float >	CVarLumenScreenProbeInterpolationDepthWeight (TEXT("r.Lumen.ScreenProbeGather.InterpolationDepthWeight"), 1.0f, TEXT("Higher values will make lighting sharper on small elements, but somewhat less stable and will spawn more adaptive probes."), ECVF_Scalability|ECVF_RenderThreadSafe)
TAutoConsoleVariable< float >	CVarLumenScreenProbeInterpolationDepthWeightForFoliage (TEXT("r.Lumen.ScreenProbeGather.InterpolationDepthWeightForFoliage"), 0.25f, TEXT("Usually can be relaxed on foliage in order to spawn less adaptive probes, as light leaking is less visible on foliage."), ECVF_Scalability|ECVF_RenderThreadSafe)
int32	GLumenScreenProbeTemporalFilter = 1
int32	GLumenScreenProbeClearHistoryEveryFrame = 0
FAutoConsoleVariableRef	CVarLumenScreenProbeClearHistoryEveryFrame (TEXT("r.Lumen.ScreenProbeGather.Temporal.ClearHistoryEveryFrame"), GLumenScreenProbeClearHistoryEveryFrame, TEXT("Whether to clear the history every frame for debugging"), ECVF_RenderThreadSafe)
TAutoConsoleVariable< float >	CVarLumenScreenProbeHistoryDistanceThreshold (TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold"), 0.01f, 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)
TAutoConsoleVariable< float >	CVarLumenScreenProbeHistoryDistanceThresholdForFoliage (TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThresholdForFoliage"), 0.03f, TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold which only affects foliage pixels. Often foliage has lots of discontinuities and edges and it's beneficial to be more agressive with keeping history there."), ECVF_Scalability|ECVF_RenderThreadSafe)
float	GLumenScreenProbeFractionOfLightingMovingForFastUpdateMode = .1f
float	GLumenScreenProbeTemporalMaxFastUpdateModeAmount = .9f
int32	GLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp = 0
float	GLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving = .005f
float	GLumenScreenProbeTemporalMaxFramesAccumulated = 10.0f
TAutoConsoleVariable< int32 >	CVarLumenScreenProbeTemporalMaxRayDirections (TEXT("r.Lumen.ScreenProbeGather.Temporal.MaxRayDirections"), 8, TEXT("Number of possible random directions per pixel. Should be tweaked based on MaxFramesAccumulated."), ECVF_Scalability|ECVF_RenderThreadSafe)
float	GLumenScreenProbeTemporalHistoryNormalThreshold = 45.0f
float	GLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback = 2
int32	GLumenScreenProbeSpatialFilter = 1
int32	GLumenScreenProbeTemporalFilterProbes = 0
int32	GLumenScreenProbeExtraAmbientOcclusion = 0
float	GLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace = 500.0f
float	GLumenScreenProbeExtraAmbientOcclusionExponent = .5f
int32	GLumenShortRangeAmbientOcclusion = 1
int32	GLumenScreenProbeFixedJitterIndex = -1
int32	GLumenRadianceCache = 1
int32	GLumenScreenProbeIrradianceFormat = 1
int32	GLumenScreenProbeStochasticInterpolation = 1
int32	GLumenScreenProbeTileDebugMode = 0
const FIntPoint	LumenScreenProbeGather::AdaptiveSamplesPerPassXY (2, 2)
int32	GRadianceCacheNumClipmaps = 4
FAutoConsoleVariableRef	CVarRadianceCacheNumClipmaps (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.NumClipmaps"), GRadianceCacheNumClipmaps, TEXT("Number of radiance cache clipmaps."), ECVF_RenderThreadSafe)
float	GLumenRadianceCacheClipmapWorldExtent = 2500.0f
FAutoConsoleVariableRef	CVarLumenRadianceCacheClipmapWorldExtent (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ClipmapWorldExtent"), GLumenRadianceCacheClipmapWorldExtent, TEXT("World space extent of the first clipmap"), ECVF_RenderThreadSafe)
float	GLumenRadianceCacheClipmapDistributionBase = 2.0f
FAutoConsoleVariableRef	CVarLumenRadianceCacheClipmapDistributionBase (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ClipmapDistributionBase"), GLumenRadianceCacheClipmapDistributionBase, TEXT("Base of the Pow() that controls the size of each successive clipmap relative to the first."), ECVF_RenderThreadSafe)
int32	GRadianceCacheGridResolution = 48
FAutoConsoleVariableRef	CVarRadianceCacheResolution (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.GridResolution"), GRadianceCacheGridResolution, TEXT("Resolution of the probe placement grid within each clipmap"), ECVF_RenderThreadSafe)
int32	GRadianceCacheProbeResolution = 32
int32	GRadianceCacheNumMipmaps = 1
float	GRadianceCacheReprojectionRadiusScale = 1.5f
FAutoConsoleVariableRef	CVarRadianceCacheProbeReprojectionRadiusScale (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ReprojectionRadiusScale"), GRadianceCacheReprojectionRadiusScale, TEXT(""), ECVF_RenderThreadSafe)
int32	GRadianceCacheStats = 0
FAutoConsoleVariableRef	CVarRadianceCacheStats (TEXT("r.Lumen.ScreenProbeGather.RadianceCache.Stats"), GRadianceCacheStats, TEXT("GPU print out Radiance Cache update stats."), ECVF_RenderThreadSafe)
const int32	GScreenProbeIntegrateTileSize = 8
float	GLumenMaxShortRangeAOMultibounceAlbedo

Function Documentation

AddLumenScreenProbeDebugPass()

void AddLumenScreenProbeDebugPass	(	FRDGBuilder &	GraphBuilder,
		FViewInfo &	View,
		const FIntPoint &	ViewportIntegrateTileDimensions,
		const FIntPoint &	ViewportIntegrateTileDimensionsWithOverflow,
		FRDGBufferRef	IntegrateTileData,
		FRDGBufferRef	IntegrateIndirectArgs
	)

CVarLumenScreenProbeDiffuseIntegralMethod()

FAutoConsoleVariableRef CVarLumenScreenProbeDiffuseIntegralMethod	(	TEXT("r.Lumen.ScreenProbeGather.DiffuseIntegralMethod")	,
		GLumenScreenProbeDiffuseIntegralMethod	,
		TEXT("Preintegrated for probe (see IrradianceFormat) = 0, Importance Sample BRDF = 1, Numerical Integral Reference = 2")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeFractionOfLightingMovingForFastUpdateMode()

FAutoConsoleVariableRef CVarLumenScreenProbeFractionOfLightingMovingForFastUpdateMode	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.FractionOfLightingMovingForFastUpdateMode")	,
		GLumenScreenProbeFractionOfLightingMovingForFastUpdateMode	,
		TEXT("")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeGatherTraceMeshSDFs()

FAutoConsoleVariableRef CVarLumenScreenProbeGatherTraceMeshSDFs	(	TEXT("r.Lumen.ScreenProbeGather.TraceMeshSDFs")	,
		GLumenGatherCvars.	TraceMeshSDFs,
		TEXT("Whether to trace against Mesh Signed Distance fields for Lumen's Screen Probe Gather.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeIntegrationTileClassification()

FAutoConsoleVariableRef CVarLumenScreenProbeIntegrationTileClassification	(	TEXT("r.Lumen.ScreenProbeGather.IntegrationTileClassification")	,
		GLumenScreenProbeIntegrationTileClassification	,
		TEXT("Whether to use tile classification during diffuse integration. Tile Classification splits compute dispatches by VGPRs for better occupancy, but can introduce errors if implemented incorrectly.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeIrradianceFormat()

FAutoConsoleVariableRef CVarLumenScreenProbeIrradianceFormat	(	TEXT("r.Lumen.ScreenProbeGather.IrradianceFormat")	,
		GLumenScreenProbeIrradianceFormat	,
		TEXT("1 - Octahedral probe. Faster, but reverts to SH3 when ShortRangeAO.ApplyDuringIntegration is enabled together with BentNormal")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeMaterialAO()

FAutoConsoleVariableRef CVarLumenScreenProbeMaterialAO	(	TEXT("r.Lumen.ScreenProbeGather.MaterialAO")	,
		GLumenScreenProbeMaterialAO	,
		TEXT("Whether to apply Material Ambient Occlusion or Material Bent Normal to Lumen GI.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving()

FAutoConsoleVariableRef CVarLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.RelativeSpeedDifferenceToConsiderLightingMoving")	,
		GLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving	,
		TEXT("")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback()

FAutoConsoleVariableRef CVarLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback	(	TEXT("r.Lumen.ScreenProbeGather.ScreenTraces.ThicknessScaleWhenNoFallback")	,
		GLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback	,
		TEXT("Larger scales effectively treat depth buffer surfaces as thicker for screen traces when there is no Distance Field present to resume the occluded ray.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeStochasticInterpolation()

FAutoConsoleVariableRef CVarLumenScreenProbeStochasticInterpolation	(	TEXT("r.Lumen.ScreenProbeGather.StochasticInterpolation")	,
		GLumenScreenProbeStochasticInterpolation	,
		TEXT("Where to interpolate screen probes stochastically (1 sample) or bilinearly (4 samples)")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeSupportBackfaceDiffuse()

FAutoConsoleVariableRef CVarLumenScreenProbeSupportBackfaceDiffuse	(	TEXT("r.Lumen.ScreenProbeGather.TwoSidedFoliageBackfaceDiffuse")	,
		GLumenScreenProbeSupportTwoSidedFoliageBackfaceDiffuse	,
		TEXT("Whether to gather lighting along the backface for the Two Sided Foliage shading model, which adds some GPU cost. The final lighting is then DiffuseColor * FrontfaceLighting + SubsurfaceColor * BackfaceLighting. When disabled, SubsurfaceColor will simply be added to DiffuseColor instead.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp()

FAutoConsoleVariableRef CVarLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.FastUpdateModeUseNeighborhoodClamp")	,
		GLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp	,
		TEXT("Whether to clamp history values to the current frame's screen space neighborhood, in areas around moving objects.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeTemporalFilter()

FAutoConsoleVariableRef CVarLumenScreenProbeTemporalFilter	(	TEXT("r.Lumen.ScreenProbeGather.Temporal")	,
		GLumenScreenProbeTemporalFilter	,
		TEXT("Whether to use a temporal filter")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeTemporalHistoryNormalThreshold()

FAutoConsoleVariableRef CVarLumenScreenProbeTemporalHistoryNormalThreshold	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.NormalThreshold")	,
		GLumenScreenProbeTemporalHistoryNormalThreshold	,
		TEXT("Maximum angle that the history texel's normal can be from the current pixel to accept it's history lighting, in degrees.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeTemporalMaxFastUpdateModeAmount()

FAutoConsoleVariableRef CVarLumenScreenProbeTemporalMaxFastUpdateModeAmount	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.MaxFastUpdateModeAmount")	,
		GLumenScreenProbeTemporalMaxFastUpdateModeAmount	,
		TEXT("Maximum amount of fast-responding temporal filter to use when traces hit a moving object. Values closer to 1 cause more noise, but also faster reaction to scene changes.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeTemporalMaxFramesAccumulated()

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

CVarLumenScreenProbeUseJitter()

FAutoConsoleVariableRef CVarLumenScreenProbeUseJitter	(	TEXT("r.Lumen.ScreenProbeGather.FixedJitterIndex")	,
		GLumenScreenProbeFixedJitterIndex	,
		TEXT("If zero or greater, overrides the temporal jitter index with a fixed index. Useful for debugging and inspecting sampling patterns.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarRadianceCache()

FAutoConsoleVariableRef CVarRadianceCache	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache")	,
		GLumenRadianceCache	,
		TEXT("Whether to enable the Persistent world space Radiance Cache")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarRadianceCacheNumMipmaps()

FAutoConsoleVariableRef CVarRadianceCacheNumMipmaps	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.NumMipmaps")	,
		GRadianceCacheNumMipmaps	,
		TEXT("Number of radiance cache mipmaps.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarRadianceCacheProbeResolution()

FAutoConsoleVariableRef CVarRadianceCacheProbeResolution	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ProbeResolution")	,
		GRadianceCacheProbeResolution	,
		TEXT("Resolution of the probe's 2d radiance layout. The number of rays traced for the probe will be ProbeResolution ^ 2")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

DECLARE_GPU_STAT()

DECLARE_GPU_STAT

(

LumenScreenProbeGather

)

GetClassificationModeString()

const TCHAR * GetClassificationModeString

(

EScreenProbeIntegrateTileClassification

Mode

)

GVarAdaptiveProbeAllocationFraction()

FAutoConsoleVariableRef GVarAdaptiveProbeAllocationFraction	(	TEXT("r.Lumen.ScreenProbeGather.AdaptiveProbeAllocationFraction")	,
		GLumenScreenProbeGatherAdaptiveProbeAllocationFraction	,
		TEXT("Fraction of uniform probes to allow for adaptive probe placement.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeDownsampleFactor()

FAutoConsoleVariableRef GVarLumenScreenProbeDownsampleFactor	(	TEXT("r.Lumen.ScreenProbeGather.DownsampleFactor")	,
		GLumenScreenProbeDownsampleFactor	,
		TEXT("Pixel size of the screen tile that a screen probe will be placed on.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeExtraAmbientOcclusion()

FAutoConsoleVariableRef GVarLumenScreenProbeExtraAmbientOcclusion	(	TEXT("r.Lumen.ScreenProbeGather.ExtraAmbientOcclusion")	,
		GLumenScreenProbeExtraAmbientOcclusion	,
		TEXT("1: Extra AO on")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeExtraAmbientOcclusionExponent()

FAutoConsoleVariableRef GVarLumenScreenProbeExtraAmbientOcclusionExponent	(	TEXT("r.Lumen.ScreenProbeGather.ExtraAmbientOcclusion.Exponent")	,
		GLumenScreenProbeExtraAmbientOcclusionExponent	,
		TEXT("Exponent applied to the distance fraction of an occluder to calculate its occlusion. Values smaller than one reduce the occlusion of nearby objects, while values larger than one increase the occlusion of nearby objects.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace()

FAutoConsoleVariableRef GVarLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace	(	TEXT("r.Lumen.ScreenProbeGather.ExtraAmbientOcclusion.MaxDistanceWorldSpace")	,
		GLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace	,
		TEXT("Maximum distance from the receiver surface that another surface in the world should cause ambient occlusion.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeFilter()

FAutoConsoleVariableRef GVarLumenScreenProbeFilter	(	TEXT("r.Lumen.ScreenProbeGather.SpatialFilterProbes")	,
		GLumenScreenProbeSpatialFilter	,
		TEXT("Whether to spatially filter probe traces to reduce noise.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeFullResolutionJitterWidth()

FAutoConsoleVariableRef GVarLumenScreenProbeFullResolutionJitterWidth	(	TEXT("r.Lumen.ScreenProbeGather.FullResolutionJitterWidth")	,
		GLumenScreenProbeFullResolutionJitterWidth	,
		TEXT("Size of the full resolution jitter applied to Screen Probe upsampling, as a fraction of a screen tile. A width of 1 results in jittering by DownsampleFactor number of pixels.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeGather()

FAutoConsoleVariableRef GVarLumenScreenProbeGather	(	TEXT("r.Lumen.ScreenProbeGather")	,
		GLumenScreenProbeGather	,
		TEXT("Whether to use the Screen Probe Final Gather")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeGatherOctahedronResolutionScale()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherOctahedronResolutionScale	(	TEXT("r.Lumen.ScreenProbeGather.GatherOctahedronResolutionScale")	,
		GLumenScreenProbeGatherOctahedronResolutionScale	,
		TEXT("Resolution that probe filtering and integration will happen at, as a scale of TracingOctahedronResolution")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeGatherReferenceMode()

FAutoConsoleVariableRef GVarLumenScreenProbeGatherReferenceMode	(	TEXT("r.Lumen.ScreenProbeGather.ReferenceMode")	,
		GLumenScreenProbeGatherReferenceMode	,
		TEXT("When enabled, traces 1024 uniform rays per probe with no filtering, Importance Sampling or Radiance Caching.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeTemporalFilter()

FAutoConsoleVariableRef GVarLumenScreenProbeTemporalFilter	(	TEXT("r.Lumen.ScreenProbeGather.TemporalFilterProbes")	,
		GLumenScreenProbeTemporalFilterProbes	,
		TEXT("Whether to temporally filter probe traces to reduce noise.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeTileDebugMode()

FAutoConsoleVariableRef GVarLumenScreenProbeTileDebugMode	(	TEXT("r.Lumen.ScreenProbeGather.TileDebugMode")	,
		GLumenScreenProbeTileDebugMode	,
		TEXT("Display Lumen screen probe tile classification.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenProbeTracingOctahedronResolution()

FAutoConsoleVariableRef GVarLumenScreenProbeTracingOctahedronResolution	(	TEXT("r.Lumen.ScreenProbeGather.TracingOctahedronResolution")	,
		GLumenScreenProbeTracingOctahedronResolution	,
		TEXT("Resolution of the tracing octahedron. Determines how many traces are done per probe.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

GVarLumenScreenSpaceShortRangeAO()

FAutoConsoleVariableRef GVarLumenScreenSpaceShortRangeAO	(	TEXT("r.Lumen.ScreenProbeGather.ShortRangeAO")	,
		GLumenShortRangeAmbientOcclusion	,
		TEXT("Whether to compute a short range, full resolution AO to add high frequency occlusion (contact shadows) which Screen Probes lack due to downsampling.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

IMPLEMENT_GLOBAL_SHADER() [1/13]

IMPLEMENT_GLOBAL_SHADER	(	FInitScreenProbeTileIndirectArgsCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"InitScreenProbeTileIndirectArgsCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [2/13]

IMPLEMENT_GLOBAL_SHADER	(	FLumenScreenProbeSubstrateDebugPass	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"ScreenProbeDebugMain"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [3/13]

IMPLEMENT_GLOBAL_SHADER	(	FMarkRadianceProbesUsedByHairStrandsCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"MarkRadianceProbesUsedByHairStrandsCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [4/13]

IMPLEMENT_GLOBAL_SHADER	(	FMarkRadianceProbesUsedByScreenProbesCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"MarkRadianceProbesUsedByScreenProbesCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [5/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeAdaptivePlacementMarkCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"ScreenProbeAdaptivePlacementMarkCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [6/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeAdaptivePlacementSpawnCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"ScreenProbeAdaptivePlacementSpawnCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [7/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeDownsampleDepthUniformCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"ScreenProbeDownsampleDepthUniformCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [8/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeGatherDebugCS	,
		"/Engine/Private/Lumen/LumenScreenProbeDebug.usf"	,
		"ScreenProbeGatherDebugCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [9/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeIntegrateClearUnusedTileDataCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"ScreenProbeIntegrateClearUnusedTileDataCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [10/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeIntegrateCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"ScreenProbeIntegrateCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [11/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeTemporalReprojectionCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGatherTemporal.usf"	,
		"ScreenProbeTemporalReprojectionCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [12/13]

IMPLEMENT_GLOBAL_SHADER	(	FScreenProbeTileClassificationBuildListsCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"ScreenProbeTileClassificationBuildListsCS"	,
		SF_Compute
	)

IMPLEMENT_GLOBAL_SHADER() [13/13]

IMPLEMENT_GLOBAL_SHADER	(	FSetupAdaptiveProbeIndirectArgsCS	,
		"/Engine/Private/Lumen/LumenScreenProbeGather.usf"	,
		"SetupAdaptiveProbeIndirectArgsCS"	,
		SF_Compute
	)

InterpolateAndIntegrate()

void InterpolateAndIntegrate	(	FRDGBuilder &	GraphBuilder,
		const FSceneTextures &	SceneTextures,
		FViewInfo &	View,
		const FLumenSceneFrameTemporaries &	FrameTemporaries,
		const FScreenProbeParameters &	ScreenProbeParameters,
		const FScreenProbeGatherParameters &	GatherParameters,
		FScreenProbeIntegrateParameters &	IntegrateParameters,
		const FLumenScreenSpaceBentNormalParameters &	ScreenSpaceBentNormalParameters,
		EReflectionsMethod	ReflectionsMethod,
		FRDGTextureRef	DiffuseIndirect,
		FRDGTextureRef	LightIsMoving,
		FRDGTextureRef	BackfaceDiffuseIndirect,
		FRDGTextureRef	RoughSpecularIndirect,
		ERDGPassFlags	ComputePassFlags
	)

SupportsHairScreenTraces()

bool SupportsHairScreenTraces

(

)

UpdateHistoryScreenProbeGather()

void UpdateHistoryScreenProbeGather	(	FRDGBuilder &	GraphBuilder,
		const FViewInfo &	View,
		const FSceneTextures &	SceneTextures,
		FLumenSceneFrameTemporaries &	FrameTemporaries,
		const FScreenProbeGatherCommonParameters &	ScreenProbeGatherCommonParameters,
		const FScreenProbeIntegrateParameters &	IntegrateParameters,
		FLumenScreenSpaceBentNormalParameters &	ScreenSpaceBentNormalParameters,
		bool	bPropagateGlobalLightingChange,
		FRDGTextureRef &	DiffuseIndirect,
		FRDGTextureRef	LightIsMoving,
		FRDGTextureRef &	BackfaceDiffuseIndirect,
		FRDGTextureRef &	RoughSpecularIndirect,
		ERDGPassFlags	ComputePassFlags
	)

Variable Documentation

CVarLumenRadianceCacheClipmapDistributionBase

FAutoConsoleVariableRef CVarLumenRadianceCacheClipmapDistributionBase(TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ClipmapDistributionBase"), GLumenRadianceCacheClipmapDistributionBase, TEXT("Base of the Pow() that controls the size of each successive clipmap relative to the first."), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ClipmapDistributionBase")	,
		GLumenRadianceCacheClipmapDistributionBase	,
		TEXT("Base of the Pow() that controls the size of each successive clipmap relative to the first.")	,
		ECVF_RenderThreadSafe
	)

CVarLumenRadianceCacheClipmapWorldExtent

FAutoConsoleVariableRef CVarLumenRadianceCacheClipmapWorldExtent(TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ClipmapWorldExtent"), GLumenRadianceCacheClipmapWorldExtent, TEXT("World space extent of the first clipmap"), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ClipmapWorldExtent")	,
		GLumenRadianceCacheClipmapWorldExtent	,
		TEXT("World space extent of the first clipmap")	,
		ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeClearHistoryEveryFrame

FAutoConsoleVariableRef CVarLumenScreenProbeClearHistoryEveryFrame(TEXT("r.Lumen.ScreenProbeGather.Temporal.ClearHistoryEveryFrame"), GLumenScreenProbeClearHistoryEveryFrame, TEXT("Whether to clear the history every frame for debugging"), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.ClearHistoryEveryFrame")	,
		GLumenScreenProbeClearHistoryEveryFrame	,
		TEXT("Whether to clear the history every frame for debugging")	,
		ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeHistoryDistanceThreshold

TAutoConsoleVariable< float > CVarLumenScreenProbeHistoryDistanceThreshold(TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold"), 0.01f, 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)	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold")	,
		0.	01f,
		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
	)

CVarLumenScreenProbeHistoryDistanceThresholdForFoliage

TAutoConsoleVariable< float > CVarLumenScreenProbeHistoryDistanceThresholdForFoliage(TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThresholdForFoliage"), 0.03f, TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold which only affects foliage pixels. Often foliage has lots of discontinuities and edges and it's beneficial to be more agressive with keeping history there."), ECVF_Scalability|ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThresholdForFoliage")	,
		0.	03f,
		TEXT("r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold which only affects foliage pixels. Often foliage has lots of discontinuities and edges and it's beneficial to be more agressive with keeping history there.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeInterpolationDepthWeight

TAutoConsoleVariable< float > CVarLumenScreenProbeInterpolationDepthWeight(TEXT("r.Lumen.ScreenProbeGather.InterpolationDepthWeight"), 1.0f, TEXT("Higher values will make lighting sharper on small elements, but somewhat less stable and will spawn more adaptive probes."), ECVF_Scalability|ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.InterpolationDepthWeight")	,
		1.	0f,
		TEXT("Higher values will make lighting sharper on small elements, but somewhat less stable and will spawn more adaptive probes.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeInterpolationDepthWeightForFoliage

TAutoConsoleVariable< float > CVarLumenScreenProbeInterpolationDepthWeightForFoliage(TEXT("r.Lumen.ScreenProbeGather.InterpolationDepthWeightForFoliage"), 0.25f, TEXT("Usually can be relaxed on foliage in order to spawn less adaptive probes, as light leaking is less visible on foliage."), ECVF_Scalability|ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.InterpolationDepthWeightForFoliage")	,
		0.	25f,
		TEXT("Usually can be relaxed on foliage in order to spawn less adaptive probes, as light leaking is less visible on foliage.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarLumenScreenProbeTemporalMaxRayDirections

TAutoConsoleVariable< int32 > CVarLumenScreenProbeTemporalMaxRayDirections(TEXT("r.Lumen.ScreenProbeGather.Temporal.MaxRayDirections"), 8, TEXT("Number of possible random directions per pixel. Should be tweaked based on MaxFramesAccumulated."), ECVF_Scalability|ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.Temporal.MaxRayDirections")	,
		8	,
		TEXT("Number of possible random directions per pixel. Should be tweaked based on MaxFramesAccumulated.")	,
		ECVF_Scalability|	ECVF_RenderThreadSafe
	)

CVarRadianceCacheNumClipmaps

FAutoConsoleVariableRef CVarRadianceCacheNumClipmaps(TEXT("r.Lumen.ScreenProbeGather.RadianceCache.NumClipmaps"), GRadianceCacheNumClipmaps, TEXT("Number of radiance cache clipmaps."), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.NumClipmaps")	,
		GRadianceCacheNumClipmaps	,
		TEXT("Number of radiance cache clipmaps.")	,
		ECVF_RenderThreadSafe
	)

CVarRadianceCacheProbeReprojectionRadiusScale

FAutoConsoleVariableRef CVarRadianceCacheProbeReprojectionRadiusScale(TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ReprojectionRadiusScale"), GRadianceCacheReprojectionRadiusScale, TEXT(""), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.ReprojectionRadiusScale")	,
		GRadianceCacheReprojectionRadiusScale	,
		TEXT("")	,
		ECVF_RenderThreadSafe
	)

CVarRadianceCacheResolution

FAutoConsoleVariableRef CVarRadianceCacheResolution(TEXT("r.Lumen.ScreenProbeGather.RadianceCache.GridResolution"), GRadianceCacheGridResolution, TEXT("Resolution of the probe placement grid within each clipmap"), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.GridResolution")	,
		GRadianceCacheGridResolution	,
		TEXT("Resolution of the probe placement grid within each clipmap")	,
		ECVF_RenderThreadSafe
	)

CVarRadianceCacheStats

FAutoConsoleVariableRef CVarRadianceCacheStats(TEXT("r.Lumen.ScreenProbeGather.RadianceCache.Stats"), GRadianceCacheStats, TEXT("GPU print out Radiance Cache update stats."), ECVF_RenderThreadSafe)	(	TEXT("r.Lumen.ScreenProbeGather.RadianceCache.Stats")	,
		GRadianceCacheStats	,
		TEXT("GPU print out Radiance Cache update stats.")	,
		ECVF_RenderThreadSafe
	)

GLumenGatherCvars

FLumenGatherCvarState GLumenGatherCvars

extern

GLumenMaxShortRangeAOMultibounceAlbedo

float GLumenMaxShortRangeAOMultibounceAlbedo

extern

GLumenRadianceCache

int32 GLumenRadianceCache = 1

GLumenRadianceCacheClipmapDistributionBase

float GLumenRadianceCacheClipmapDistributionBase = 2.0f

GLumenRadianceCacheClipmapWorldExtent

float GLumenRadianceCacheClipmapWorldExtent = 2500.0f

GLumenScreenProbeClearHistoryEveryFrame

int32 GLumenScreenProbeClearHistoryEveryFrame = 0

GLumenScreenProbeDiffuseIntegralMethod

int32 GLumenScreenProbeDiffuseIntegralMethod = 0

GLumenScreenProbeDownsampleFactor

int32 GLumenScreenProbeDownsampleFactor = 16

GLumenScreenProbeExtraAmbientOcclusion

int32 GLumenScreenProbeExtraAmbientOcclusion = 0

GLumenScreenProbeExtraAmbientOcclusionExponent

float GLumenScreenProbeExtraAmbientOcclusionExponent = .5f

GLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace

float GLumenScreenProbeExtraAmbientOcclusionMaxDistanceWorldSpace = 500.0f

GLumenScreenProbeFixedJitterIndex

int32 GLumenScreenProbeFixedJitterIndex = -1

GLumenScreenProbeFractionOfLightingMovingForFastUpdateMode

float GLumenScreenProbeFractionOfLightingMovingForFastUpdateMode = .1f

GLumenScreenProbeFullResolutionJitterWidth

float GLumenScreenProbeFullResolutionJitterWidth = 1

GLumenScreenProbeGather

int32 GLumenScreenProbeGather = 1

GLumenScreenProbeGatherAdaptiveProbeAllocationFraction

float GLumenScreenProbeGatherAdaptiveProbeAllocationFraction = .5f

GLumenScreenProbeGatherOctahedronResolutionScale

float GLumenScreenProbeGatherOctahedronResolutionScale = 1.0f

GLumenScreenProbeGatherReferenceMode

int32 GLumenScreenProbeGatherReferenceMode = 0

GLumenScreenProbeIntegrationTileClassification

int32 GLumenScreenProbeIntegrationTileClassification = 1

GLumenScreenProbeIrradianceFormat

int32 GLumenScreenProbeIrradianceFormat = 1

GLumenScreenProbeMaterialAO

int32 GLumenScreenProbeMaterialAO = 1

GLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving

float GLumenScreenProbeRelativeSpeedDifferenceToConsiderLightingMoving = .005f

GLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback

float GLumenScreenProbeScreenTracesThicknessScaleWhenNoFallback = 2

GLumenScreenProbeSpatialFilter

int32 GLumenScreenProbeSpatialFilter = 1

GLumenScreenProbeStochasticInterpolation

int32 GLumenScreenProbeStochasticInterpolation = 1

GLumenScreenProbeSupportTwoSidedFoliageBackfaceDiffuse

int32 GLumenScreenProbeSupportTwoSidedFoliageBackfaceDiffuse = 1

GLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp

int32 GLumenScreenProbeTemporalFastUpdateModeUseNeighborhoodClamp = 0

GLumenScreenProbeTemporalFilter

int32 GLumenScreenProbeTemporalFilter = 1

GLumenScreenProbeTemporalFilterProbes

int32 GLumenScreenProbeTemporalFilterProbes = 0

GLumenScreenProbeTemporalHistoryNormalThreshold

float GLumenScreenProbeTemporalHistoryNormalThreshold = 45.0f

GLumenScreenProbeTemporalMaxFastUpdateModeAmount

float GLumenScreenProbeTemporalMaxFastUpdateModeAmount = .9f

GLumenScreenProbeTemporalMaxFramesAccumulated

float GLumenScreenProbeTemporalMaxFramesAccumulated = 10.0f

GLumenScreenProbeTileDebugMode

int32 GLumenScreenProbeTileDebugMode = 0

GLumenScreenProbeTracingOctahedronResolution

int32 GLumenScreenProbeTracingOctahedronResolution = 8

GLumenShortRangeAmbientOcclusion

int32 GLumenShortRangeAmbientOcclusion = 1

GRadianceCacheGridResolution

int32 GRadianceCacheGridResolution = 48

GRadianceCacheNumClipmaps

int32 GRadianceCacheNumClipmaps = 4

GRadianceCacheNumMipmaps

int32 GRadianceCacheNumMipmaps = 1

GRadianceCacheProbeResolution

int32 GRadianceCacheProbeResolution = 32

GRadianceCacheReprojectionRadiusScale

float GRadianceCacheReprojectionRadiusScale = 1.5f

GRadianceCacheStats

int32 GRadianceCacheStats = 0

GScreenProbeIntegrateTileSize

const int32 GScreenProbeIntegrateTileSize = 8