RayTracingBasicShaders.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "BuiltInRayTracingShaders.h"
 
#if RHI_RAYTRACING
 
#include "RayTracingPayloadType.h"
 
// C++ counter-part of FBasicRayData declared in RayTracingCommon.ush
struct FBasicRayTracingRay
{
    float Origin[3];
    uint32 Mask;
    float Direction[3];
    float TFar;
};
 
// C++ counter-part of FIntersectionPayload declared in RayTracingCommon.ush
struct FBasicRayTracingIntersectionResult
{
    float  HitT;            // Distance from ray origin to the intersection point in the ray direction. Negative on miss.
    uint32 PrimitiveIndex;  // Index of the primitive within the geometry inside the bottom-level acceleration structure instance. Undefined on miss.
    uint32 InstanceIndex;   // Index of the current instance in the top-level structure. Undefined on miss.
    float  Barycentrics[2]; // Primitive barycentric coordinates of the intersection point. Undefined on miss.
};
 
class FBasicOcclusionMainRGS : public FBuiltInRayTracingShader
{
    DECLARE_GLOBAL_SHADER(FBasicOcclusionMainRGS);
    SHADER_USE_ROOT_PARAMETER_STRUCT(FBasicOcclusionMainRGS, FBuiltInRayTracingShader);
 
    BEGIN_SHADER_PARAMETER_STRUCT(FParameters, )
        SHADER_PARAMETER_SRV(RaytracingAccelerationStructure, TLAS)
        SHADER_PARAMETER_SRV(StructuredBuffer<FBasicRayData>, Rays)
        SHADER_PARAMETER_UAV(RWStructuredBuffer<uint>, OcclusionOutput)
    END_SHADER_PARAMETER_STRUCT()
 
    static ERayTracingPayloadType GetRayTracingPayloadType(const int32 PermutationId)
    {
        return ERayTracingPayloadType::Default;
    }
};
 
class FBasicIntersectionMainRGS : public FBuiltInRayTracingShader
{
    DECLARE_GLOBAL_SHADER(FBasicIntersectionMainRGS);
    SHADER_USE_ROOT_PARAMETER_STRUCT(FBasicIntersectionMainRGS, FBuiltInRayTracingShader);
 
    BEGIN_SHADER_PARAMETER_STRUCT(FParameters, )
        SHADER_PARAMETER_SRV(RaytracingAccelerationStructure, TLAS)
        SHADER_PARAMETER_SRV(StructuredBuffer<FBasicRayData>, Rays)
        SHADER_PARAMETER_UAV(RWStructuredBuffer<FIntersectionPayload>, IntersectionOutput)
    END_SHADER_PARAMETER_STRUCT()
 
    static ERayTracingPayloadType GetRayTracingPayloadType(const int32 PermutationId)
    {
        return ERayTracingPayloadType::Default;
    }
};
 
class FBasicIntersectionMainCHS : public FBuiltInRayTracingShader
{
    DECLARE_GLOBAL_SHADER(FBasicIntersectionMainCHS);
public:
 
    FBasicIntersectionMainCHS() = default;
    FBasicIntersectionMainCHS(const ShaderMetaType::CompiledShaderInitializerType& Initializer)
        : FBuiltInRayTracingShader(Initializer)
    {}
 
    static ERayTracingPayloadType GetRayTracingPayloadType(const int32 PermutationId)
    {
        return ERayTracingPayloadType::Default;
    }
};
 
void DispatchBasicOcclusionRays(FRHICommandList& RHICmdList, FRHIShaderResourceView* SceneView, FRHIRayTracingGeometry* Geometry, FRHIShaderResourceView* RayBufferView, FRHIUnorderedAccessView* ResultView, uint32 NumRays);
 
void DispatchBasicIntersectionRays(FRHICommandList& RHICmdList, FRHIShaderResourceView* SceneView, FRHIRayTracingGeometry* Geometry, FRHIShaderResourceView* RayBufferView, FRHIUnorderedAccessView* ResultView, uint32 NumRays);
 
#endif // RHI_RAYTRACING