VolumetricFogShared.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "RHIDefinitions.h"
#include "SceneView.h"
#include "SceneRendering.h"
 
BEGIN_GLOBAL_SHADER_PARAMETER_STRUCT(FVoxelizeVolumePassUniformParameters, )
    SHADER_PARAMETER_STRUCT(FSceneTextureUniformParameters, SceneTextures)
    SHADER_PARAMETER(FMatrix44f, ViewToVolumeClip)
    SHADER_PARAMETER(FVector2f, ClipRatio)
    SHADER_PARAMETER(FVector4f, FrameJitterOffset0)
    SHADER_PARAMETER_STRUCT(FVolumetricFogGlobalData, VolumetricFog)
    SHADER_PARAMETER(FVector3f, RenderVolumetricCloudParametersCloudLayerCenterKm)
    SHADER_PARAMETER(float, RenderVolumetricCloudParametersPlanetRadiusKm)
    SHADER_PARAMETER(float, RenderVolumetricCloudParametersBottomRadiusKm)
    SHADER_PARAMETER(float, RenderVolumetricCloudParametersTopRadiusKm)
END_GLOBAL_SHADER_PARAMETER_STRUCT()
 
extern FVector3f VolumetricFogTemporalRandom(uint32 FrameNumber);
 
float GetVolumetricFogLightSoftFading();
 
struct FVolumetricFogIntegrationParameterData
{
    FVolumetricFogIntegrationParameterData() :
        bTemporalHistoryIsValid(false)
    {}
 
    bool bTemporalHistoryIsValid;
    TArray<FVector4f, TInlineAllocator<16>> FrameJitterOffsetValues;
    FRDGTexture* VBufferA;
    FRDGTexture* VBufferB;
    FRDGTextureUAV* VBufferA_UAV;
    FRDGTextureUAV* VBufferB_UAV;
 
    FRDGTexture* LightScattering;
    FRDGTextureUAV* LightScatteringUAV;
};
 
BEGIN_SHADER_PARAMETER_STRUCT(FVolumetricFogIntegrationParameters, )
    SHADER_PARAMETER_STRUCT_REF(FVolumetricFogGlobalData, VolumetricFog)
    SHADER_PARAMETER(FMatrix44f, UnjitteredClipToTranslatedWorld)
    SHADER_PARAMETER(FMatrix44f, UnjitteredPrevTranslatedWorldToClip)
    SHADER_PARAMETER_ARRAY(FVector4f, FrameJitterOffsets, [16])
    SHADER_PARAMETER(float, HistoryWeight)
    SHADER_PARAMETER(uint32, HistoryMissSuperSampleCount)
END_SHADER_PARAMETER_STRUCT()
 
void SetupVolumetricFogIntegrationParameters(
    FVolumetricFogIntegrationParameters& Out,
    FViewInfo& View,
    const FVolumetricFogIntegrationParameterData& IntegrationData);
 
inline int32 ComputeZSliceFromDepth(float SceneDepth, FVector GridZParams)
{
    return FMath::TruncToInt(FMath::Log2(SceneDepth * GridZParams.X + GridZParams.Y) * GridZParams.Z);
}
 
extern FVector GetVolumetricFogGridZParams(float NearPlane, float FarPlane, int32 GridSizeZ);