MaterialExpressionVolumetricAdvancedMaterialOutput.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Materials/MaterialExpressionCustomOutput.h"
#include "UObject/ObjectMacros.h"
#include "Shader/ShaderTypes.h"
#include "MaterialExpressionVolumetricAdvancedMaterialOutput.generated.h"
 
UCLASS(MinimalAPI, collapsecategories, hidecategories = Object)
class UMaterialExpressionVolumetricAdvancedMaterialOutput : public UMaterialExpressionCustomOutput
{
    GENERATED_UCLASS_BODY()
 
    
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "Parameter 'g' input to the phase function  describing how much forward(g<0) or backward (g>0) light scatter around. Valid range is [-1,1]. Defaults to ConstPhaseG from properties panel if not specified. Evaluated per sample if EvaluatePhaseOncePerSample is true."))
    FExpressionInput PhaseG;
    
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "Parameter 'g' input to the second phase function  describing how much forward(g<0) or backward (g>0) light scatter around. Valid range is [-1,1]. Defaults to ConstPhaseG2 from properties panel if not specified. Evaluated per sample if EvaluatePhaseOncePerSample is true."))
    FExpressionInput PhaseG2;
    
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "Lerp factor when blending the two phase functions parameterized by G and G2. Valid range is [0,1] Defaults to ConstPhaseBlend from properties panel if not specified. Evaluated per sample if EvaluatePhaseOncePerSample is true."))
    FExpressionInput PhaseBlend;
    
 
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "Multi-scattering approximation: represents how much contribution each successive octave will add. Evaluated per pixel. Valid range is [0,1], from low to high contribution. Defaults to ConstMultiScatteringContribution from properties panel if not specified. Evaluated per pixel (globally)."))
    FExpressionInput MultiScatteringContribution;
    
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "Multi-scattering approximation: represents how much occlusion will be reduced for each successive octave. Evaluated per pixel. Valid range is [0,1], from low to high occlusion. Defaults to ConstMultiScatteringOcclusion from properties panel if not specified. Evaluated per pixel (globally)."))
    FExpressionInput MultiScatteringOcclusion;
    
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "Multi-scattering approximation: represents how much the phase will become isotropic for each successive octave. Evaluated per pixel. Valid range is [0,1], from anisotropic to isotropic phase. Defaults to ConstMultiScatteringEccentricity from properties panel if not specified. Evaluated per pixel (globally)."))
    FExpressionInput MultiScatteringEccentricity;
 
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "This is a 4-components float vector. The X component must represent the participating medium conservative density. This is used to accelerate the ray marching by early skipping expensive material evaluation. For example, the bare minimum would be a top down 2D density texture skipping evaluating the full material in empty regions (better, would be a simple blobby volume representation of clouds). The Y, Z and W components can contain parameters that can be recovered during the material graph evaluation using the VolumetricAdvancedMaterialInput node. Evaluated per sample."))
    FExpressionInput ConservativeDensity;
 
    UPROPERTY(EditAnywhere, Category = "Phase", meta = (OverridingInputProperty = "PhaseG", UIMin = -0.999f, UIMax = 0.999f, ClampMin = -0.999f, ClampMax = 0.999f))
    float ConstPhaseG = 0.0f;
 
    UPROPERTY(EditAnywhere, Category = "Phase", meta = (OverridingInputProperty = "PhaseG2", UIMin = -0.999f, UIMax = 0.999f, ClampMin = -0.999f, ClampMax = 0.999f))
    float ConstPhaseG2 = 0.0f;
 
    UPROPERTY(EditAnywhere, Category = "Phase", meta = (OverridingInputProperty = "PhaseBlend", UIMin = 0.0f, UIMax = 1.0f, ClampMin = -0.999f, ClampMax = 0.999f))
    float ConstPhaseBlend = 0.0f;
 
    UPROPERTY(EditAnywhere, Category = "Phase")
    bool PerSamplePhaseEvaluation = false;
 
    UPROPERTY(EditAnywhere, Category = "Multi-Scattering", meta = (UIMin = 0, UIMax = 1, ClampMin = 0, ClampMax = 2))
    uint32 MultiScatteringApproximationOctaveCount = 0;
 
    UPROPERTY(EditAnywhere, Category = "Multi-Scattering", meta = (OverridingInputProperty = "MultiScatteringContribution", UIMin = 0.0f, UIMax = 1.0f, ClampMin = 0.0f, ClampMax = 1.0f))
    float ConstMultiScatteringContribution = 0.5f;
 
    UPROPERTY(EditAnywhere, Category = "Multi-Scattering", meta = (OverridingInputProperty = "MultiScatteringOcclusion", UIMin = 0.0f, UIMax = 1.0f, ClampMin = 0.0f, ClampMax = 1.0f))
    float ConstMultiScatteringOcclusion = 0.5f;
 
    UPROPERTY(EditAnywhere, Category = "Multi-Scattering", meta = (OverridingInputProperty = "MultiScatteringEccentricity", UIMin = 0.0f, UIMax = 1.0f, ClampMin = 0.0f, ClampMax = 1.0f))
    float ConstMultiScatteringEccentricity = 0.5f;
 
    UPROPERTY(EditAnywhere, Category = "Options")
    bool bGroundContribution = false;
 
    UPROPERTY(EditAnywhere, Category = "Options")
    bool bGrayScaleMaterial = false;
 
    UPROPERTY(EditAnywhere, Category = "Options")
    bool bRayMarchVolumeShadow = true;
 
    UPROPERTY(EditAnywhere, Category = "Options")
    bool bClampMultiScatteringContribution = true;
 
public:
#if WITH_EDITOR
    //~ Begin UMaterialExpression Interface
    virtual int32 Compile(class FMaterialCompiler* Compiler, int32 OutputIndex) override;
    virtual void GetCaption(TArray<FString>& OutCaptions) const override;
    //~ End UMaterialExpression Interface
 
    bool GetEvaluatePhaseOncePerSample() const;
    uint32 GetMultiScatteringApproximationOctaveCount() const;
 
#endif
 
    //~ Begin UMaterialExpressionCustomOutput Interface
    virtual int32 GetNumOutputs() const override;
    virtual FString GetFunctionName() const override;
    virtual FString GetDisplayName() const override;
    //~ End UMaterialExpressionCustomOutput Interface
};
 
UCLASS(Experimental, MinimalAPI, collapsecategories, hidecategories = Object)
class UMaterialExpressionVolumetricCloudEmptySpaceSkippingOutput : public UMaterialExpressionCustomOutput
{
    GENERATED_UCLASS_BODY()
 
    
    UPROPERTY(meta = (RequiredInput = "false", ToolTip = "Specify 0 if no matter (cloud or participating media) can be found within the area, otherwise should be set > 0."))
    FExpressionInput ContainsMatter;
 
public:
#if WITH_EDITOR
    //~ Begin UMaterialExpression Interface
    virtual int32 Compile(class FMaterialCompiler* Compiler, int32 OutputIndex) override;
    virtual void GetCaption(TArray<FString>& OutCaptions) const override;
    virtual EMaterialValueType GetOutputValueType(int32 OutputIndex) override;
    //~ End UMaterialExpression Interface
#endif
 
    //~ Begin UMaterialExpressionCustomOutput Interface
    virtual int32 GetNumOutputs() const override;
    virtual FString GetFunctionName() const override;
    virtual FString GetDisplayName() const override;
    //~ End UMaterialExpressionCustomOutput Interface
};