SkyAtmosphereCommonData.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
/*=============================================================================
    SkyAtmosphereCommonData.h
=============================================================================*/
 
#pragma once
 
#include "CoreMinimal.h"
 
 
struct FSkyAtmosphereDynamicState;
class USkyAtmosphereComponent;
 
 
 
struct FAtmosphereSetup
{
    ENGINE_API static const float CmToSkyUnit;
    ENGINE_API static const float SkyUnitToCm;
 
    FVector PlanetCenterKm;     // In sky unit (kilometers)
    float BottomRadiusKm;           // idem
    float TopRadiusKm;              // idem
 
    float MultiScatteringFactor;
 
    FLinearColor RayleighScattering;// Unit is 1/km
    float RayleighDensityExpScale;
 
    FLinearColor MieScattering;     // Unit is 1/km
    FLinearColor MieExtinction;     // idem
    FLinearColor MieAbsorption;     // idem
    float MieDensityExpScale;
    float MiePhaseG;
 
    FLinearColor AbsorptionExtinction;
    float AbsorptionDensity0LayerWidth;
    float AbsorptionDensity0ConstantTerm;
    float AbsorptionDensity0LinearTerm;
    float AbsorptionDensity1ConstantTerm;
    float AbsorptionDensity1LinearTerm;
 
    FLinearColor GroundAlbedo;
 
    float TransmittanceMinLightElevationAngle;
 
    ENGINE_API FAtmosphereSetup(const USkyAtmosphereComponent& SkyAtmosphereComponent);
    ENGINE_API FAtmosphereSetup(const FSkyAtmosphereDynamicState& Ds);
 
    template<typename T> void InternalInit(const T& SkyAtmosphereComponent);
 
    ENGINE_API FLinearColor GetTransmittanceAtGroundLevel(const FVector& SunDirection) const;
 
    ENGINE_API void UpdateTransform(const FTransform& ComponentTransform, uint8 TranformMode);
    ENGINE_API void ApplyWorldOffset(const FVector& InOffset);
 
    ENGINE_API void ComputeViewData(
        const FVector& WorldCameraOrigin, const FVector& PreViewTranslation, const FVector3f& ViewForward, const FVector3f& ViewRight,
        FVector3f& SkyCameraTranslatedWorldOrigin, FVector4f& SkyPlanetTranslatedWorldCenterAndViewHeight, FMatrix44f& SkyViewLutReferential) const;
 
    uint32 GetTransmittanceAndMultiScatteringLUTsVersion() const
    {
        return TransmittanceAndMultiScatteringLUTsVersion;
    }
 
private:
    uint32 TransmittanceAndMultiScatteringLUTsVersion; // A version to know if we have to recompute the transmittance and multiple scattering LUTs.
 
    void ComputeAtmosphereVersion();
};