DistanceFieldLightingPost.cpp File Reference

#include "DistanceFieldLightingPost.h"
#include "PostProcess/PostProcessing.h"
#include "PostProcess/SceneFilterRendering.h"
#include "DistanceFieldLightingShared.h"
#include "DistanceFieldAmbientOcclusion.h"
#include "CompositionLighting/PostProcessAmbientOcclusion.h"
#include "PipelineStateCache.h"
#include "ScenePrivate.h"
#include "SceneProxies/SkyLightSceneProxy.h"
#include "DataDrivenShaderPlatformInfo.h"

Classes
class	FUpdateHistoryDepthRejectionPS
class	FFilterHistoryPS
class	FGeometryAwareUpsamplePS
class	FDistanceFieldAOUpsamplePS

Functions
bool	UseAOHistoryStabilityPass ()
bool	ShouldCompileDFLightingPostShaders (EShaderPlatform ShaderPlatform)
FGeometryAwareUpsampleParameters	SetupGeometryAwareUpsampleParameters (const FViewInfo &View, FRDGTextureRef DistanceFieldNormal, FRDGTextureRef DistanceFieldAOBentNormal)
	IMPLEMENT_GLOBAL_SHADER (FUpdateHistoryDepthRejectionPS, "/Engine/Private/DistanceFieldLightingPost.usf", "UpdateHistoryDepthRejectionPS", SF_Pixel)
	IMPLEMENT_GLOBAL_SHADER (FFilterHistoryPS, "/Engine/Private/DistanceFieldLightingPost.usf", "FilterHistoryPS", SF_Pixel)
	IMPLEMENT_SHADER_TYPE (, FGeometryAwareUpsamplePS, TEXT("/Engine/Private/DistanceFieldLightingPost.usf"), TEXT("GeometryAwareUpsamplePS"), SF_Pixel)
void	AllocateOrReuseAORenderTarget (FRDGBuilder &GraphBuilder, const FViewInfo &View, FRDGTextureRef &Texture, const TCHAR *Name, EPixelFormat Format, ETextureCreateFlags Flags)
void	GeometryAwareUpsample (FRDGBuilder &GraphBuilder, const FViewInfo &View, FRDGTextureRef DistanceFieldAOBentNormal, FRDGTextureRef DistanceFieldNormal, FRDGTextureRef BentNormalInterpolation, const FDistanceFieldAOParameters &Parameters)
bool	DistanceFieldAOUseHistory (const FViewInfo &View)
void	UpdateHistory (FRDGBuilder &GraphBuilder, const FViewInfo &View, const TCHAR *BentNormalHistoryRTName, const FSceneTextures &SceneTextures, FRDGTextureRef VelocityTexture, FRDGTextureRef DistanceFieldNormal, FRDGTextureRef BentNormalInterpolation, FIntRect *DistanceFieldAOHistoryViewRect, TRefCountPtr< IPooledRenderTarget > *BentNormalHistoryState, FRDGTextureRef &BentNormalHistoryOutput, const FDistanceFieldAOParameters &Parameters)
	IMPLEMENT_GLOBAL_SHADER (FDistanceFieldAOUpsamplePS, "/Engine/Private/DistanceFieldLightingPost.usf", "AOUpsamplePS", SF_Pixel)
void	UpsampleBentNormalAO (FRDGBuilder &GraphBuilder, const FViewInfo &View, const FSceneTextures &SceneTextures, FRDGTextureRef SceneColorTexture, FRDGTextureRef DistanceFieldAOBentNormal, bool bModulateSceneColor, bool bModulateToScreenSpaceAO)

Variables
int32	GAOUseHistory = 1
FAutoConsoleVariableRef	CVarAOUseHistory (TEXT("r.AOUseHistory"), GAOUseHistory, TEXT("Whether to apply a temporal filter to the distance field AO, which reduces flickering but also adds trails when occluders are moving."), ECVF_RenderThreadSafe)
int32	GAOClearHistory = 0
FAutoConsoleVariableRef	CVarAOClearHistory (TEXT("r.AOClearHistory"), GAOClearHistory, TEXT(""), ECVF_RenderThreadSafe)
int32	GAOHistoryStabilityPass = 1
FAutoConsoleVariableRef	CVarAOHistoryStabilityPass (TEXT("r.AOHistoryStabilityPass"), GAOHistoryStabilityPass, TEXT("Whether to gather stable results to fill in holes in the temporal reprojection. Adds some GPU cost but improves temporal stability with foliage."), ECVF_RenderThreadSafe)
float	GAOHistoryWeight = .85f
FAutoConsoleVariableRef	CVarAOHistoryWeight (TEXT("r.AOHistoryWeight"), GAOHistoryWeight, TEXT("Amount of last frame's AO to lerp into the final result. Higher values increase stability, lower values have less streaking under occluder movement."), ECVF_RenderThreadSafe)
float	GAOHistoryDistanceThreshold = 30
FAutoConsoleVariableRef	CVarAOHistoryDistanceThreshold (TEXT("r.AOHistoryDistanceThreshold"), GAOHistoryDistanceThreshold, TEXT("World space distance threshold needed to discard last frame's DFAO results. Lower values reduce ghosting from characters when near a wall but increase flickering artifacts."), ECVF_RenderThreadSafe)
float	GAOViewFadeDistanceScale = .7f
FAutoConsoleVariableRef	CVarAOViewFadeDistanceScale (TEXT("r.AOViewFadeDistanceScale"), GAOViewFadeDistanceScale, TEXT("Distance over which AO will fade out as it approaches r.AOMaxViewDistance, as a fraction of r.AOMaxViewDistance."), ECVF_RenderThreadSafe)

Function Documentation

AllocateOrReuseAORenderTarget()

void AllocateOrReuseAORenderTarget	(	FRDGBuilder &	GraphBuilder,
		const FViewInfo &	View,
		FRDGTextureRef &	Texture,
		const TCHAR *	Name,
		EPixelFormat	Format,
		ETextureCreateFlags	Flags
	)

DistanceFieldAOUseHistory()

bool DistanceFieldAOUseHistory

(

const FViewInfo &

View

)

GeometryAwareUpsample()

void GeometryAwareUpsample	(	FRDGBuilder &	GraphBuilder,
		const FViewInfo &	View,
		FRDGTextureRef	DistanceFieldAOBentNormal,
		FRDGTextureRef	DistanceFieldNormal,
		FRDGTextureRef	BentNormalInterpolation,
		const FDistanceFieldAOParameters &	Parameters
	)

IMPLEMENT_GLOBAL_SHADER() [1/3]

IMPLEMENT_GLOBAL_SHADER	(	FDistanceFieldAOUpsamplePS	,
		"/Engine/Private/DistanceFieldLightingPost.usf"	,
		"AOUpsamplePS"	,
		SF_Pixel
	)

IMPLEMENT_GLOBAL_SHADER() [2/3]

IMPLEMENT_GLOBAL_SHADER	(	FFilterHistoryPS	,
		"/Engine/Private/DistanceFieldLightingPost.usf"	,
		"FilterHistoryPS"	,
		SF_Pixel
	)

IMPLEMENT_GLOBAL_SHADER() [3/3]

IMPLEMENT_GLOBAL_SHADER	(	FUpdateHistoryDepthRejectionPS	,
		"/Engine/Private/DistanceFieldLightingPost.usf"	,
		"UpdateHistoryDepthRejectionPS"	,
		SF_Pixel
	)

IMPLEMENT_SHADER_TYPE()

IMPLEMENT_SHADER_TYPE	(	FGeometryAwareUpsamplePS	,
		TEXT("/Engine/Private/DistanceFieldLightingPost.usf")	,
		TEXT("GeometryAwareUpsamplePS")	,
		SF_Pixel
	)

SetupGeometryAwareUpsampleParameters()

FGeometryAwareUpsampleParameters SetupGeometryAwareUpsampleParameters	(	const FViewInfo &	View,
		FRDGTextureRef	DistanceFieldNormal,
		FRDGTextureRef	DistanceFieldAOBentNormal
	)

ShouldCompileDFLightingPostShaders()

bool ShouldCompileDFLightingPostShaders

(

EShaderPlatform

ShaderPlatform

)

UpdateHistory()

void UpdateHistory	(	FRDGBuilder &	GraphBuilder,
		const FViewInfo &	View,
		const TCHAR *	BentNormalHistoryRTName,
		const FSceneTextures &	SceneTextures,
		FRDGTextureRef	VelocityTexture,
		FRDGTextureRef	DistanceFieldNormal,
		FRDGTextureRef	BentNormalInterpolation,
		FIntRect *	DistanceFieldAOHistoryViewRect,
		TRefCountPtr< IPooledRenderTarget > *	BentNormalHistoryState,
		FRDGTextureRef &	BentNormalHistoryOutput,
		const FDistanceFieldAOParameters &	Parameters
	)

Parameters

DistanceFieldAOHistoryViewRect	Contains last frame's history, if non-NULL. This will be updated with the new frame's history.
BentNormalHistoryOutput	Output of Temporal Reprojection for the next step in the pipeline.

UpsampleBentNormalAO()

void UpsampleBentNormalAO	(	FRDGBuilder &	GraphBuilder,
		const FViewInfo &	View,
		const FSceneTextures &	SceneTextures,
		FRDGTextureRef	SceneColorTexture,
		FRDGTextureRef	DistanceFieldAOBentNormal,
		bool	bModulateSceneColor,
		bool	bModulateToScreenSpaceAO
	)

UseAOHistoryStabilityPass()

bool UseAOHistoryStabilityPass

(

)

Variable Documentation

CVarAOClearHistory

FAutoConsoleVariableRef CVarAOClearHistory(TEXT("r.AOClearHistory"), GAOClearHistory, TEXT(""), ECVF_RenderThreadSafe)	(	TEXT("r.AOClearHistory")	,
		GAOClearHistory	,
		TEXT("")	,
		ECVF_RenderThreadSafe
	)

CVarAOHistoryDistanceThreshold

FAutoConsoleVariableRef CVarAOHistoryDistanceThreshold(TEXT("r.AOHistoryDistanceThreshold"), GAOHistoryDistanceThreshold, TEXT("World space distance threshold needed to discard last frame's DFAO results. Lower values reduce ghosting from characters when near a wall but increase flickering artifacts."), ECVF_RenderThreadSafe)	(	TEXT("r.AOHistoryDistanceThreshold")	,
		GAOHistoryDistanceThreshold	,
		TEXT("World space distance threshold needed to discard last frame's DFAO results. Lower values reduce ghosting from characters when near a wall but increase flickering artifacts.")	,
		ECVF_RenderThreadSafe
	)

CVarAOHistoryStabilityPass

FAutoConsoleVariableRef CVarAOHistoryStabilityPass(TEXT("r.AOHistoryStabilityPass"), GAOHistoryStabilityPass, TEXT("Whether to gather stable results to fill in holes in the temporal reprojection. Adds some GPU cost but improves temporal stability with foliage."), ECVF_RenderThreadSafe)	(	TEXT("r.AOHistoryStabilityPass")	,
		GAOHistoryStabilityPass	,
		TEXT("Whether to gather stable results to fill in holes in the temporal reprojection. Adds some GPU cost but improves temporal stability with foliage.")	,
		ECVF_RenderThreadSafe
	)

CVarAOHistoryWeight

FAutoConsoleVariableRef CVarAOHistoryWeight(TEXT("r.AOHistoryWeight"), GAOHistoryWeight, TEXT("Amount of last frame's AO to lerp into the final result. Higher values increase stability, lower values have less streaking under occluder movement."), ECVF_RenderThreadSafe)	(	TEXT("r.AOHistoryWeight")	,
		GAOHistoryWeight	,
		TEXT("Amount of last frame's AO to lerp into the final result. Higher values increase stability, lower values have less streaking under occluder movement.")	,
		ECVF_RenderThreadSafe
	)

CVarAOUseHistory

FAutoConsoleVariableRef CVarAOUseHistory(TEXT("r.AOUseHistory"), GAOUseHistory, TEXT("Whether to apply a temporal filter to the distance field AO, which reduces flickering but also adds trails when occluders are moving."), ECVF_RenderThreadSafe)	(	TEXT("r.AOUseHistory")	,
		GAOUseHistory	,
		TEXT("Whether to apply a temporal filter to the distance field AO, which reduces flickering but also adds trails when occluders are moving.")	,
		ECVF_RenderThreadSafe
	)

CVarAOViewFadeDistanceScale

FAutoConsoleVariableRef CVarAOViewFadeDistanceScale(TEXT("r.AOViewFadeDistanceScale"), GAOViewFadeDistanceScale, TEXT("Distance over which AO will fade out as it approaches r.AOMaxViewDistance, as a fraction of r.AOMaxViewDistance."), ECVF_RenderThreadSafe)	(	TEXT("r.AOViewFadeDistanceScale")	,
		GAOViewFadeDistanceScale	,
		TEXT("Distance over which AO will fade out as it approaches r.AOMaxViewDistance, as a fraction of r.AOMaxViewDistance.")	,
		ECVF_RenderThreadSafe
	)

GAOClearHistory

int32 GAOClearHistory = 0

GAOHistoryDistanceThreshold

float GAOHistoryDistanceThreshold = 30

GAOHistoryStabilityPass

int32 GAOHistoryStabilityPass = 1

GAOHistoryWeight

float GAOHistoryWeight = .85f

GAOUseHistory

int32 GAOUseHistory = 1

GAOViewFadeDistanceScale

float GAOViewFadeDistanceScale = .7f