117 lines
No EOL
3 KiB
Text
117 lines
No EOL
3 KiB
Text
/* Copyright (c) 2025, Sascha Willems
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*
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* SPDX-License-Identifier: MIT
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*
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*/
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import payload;
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struct Attributes
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{
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float2 bary;
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};
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RaytracingAccelerationStructure accelStruct;
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RWTexture2D<float4> image;
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struct UBO
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{
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float4x4 viewInverse;
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float4x4 projInverse;
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float4 lightPos;
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int vertexSize;
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};
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ConstantBuffer<UBO> ubo;
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StructuredBuffer<float4> vertices;
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StructuredBuffer<uint> indices;
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struct Vertex
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{
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float3 pos;
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float3 normal;
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float2 uv;
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float4 color;
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float4 _pad0;
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float4 _pad1;
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};
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Vertex unpack(uint index)
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{
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// Unpack the vertices from the SSBO using the glTF vertex structure
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// The multiplier is the size of the vertex divided by four float components (=16 bytes)
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const int m = ubo.vertexSize / 16;
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float4 d0 = vertices[m * index + 0];
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float4 d1 = vertices[m * index + 1];
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float4 d2 = vertices[m * index + 2];
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Vertex v;
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v.pos = d0.xyz;
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v.normal = float3(d0.w, d1.x, d1.y);
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v.color = float4(d2.x, d2.y, d2.z, 1.0);
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return v;
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}
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[shader("raygeneration")]
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void raygenerationMain()
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{
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uint3 LaunchID = DispatchRaysIndex();
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uint3 LaunchSize = DispatchRaysDimensions();
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const float2 pixelCenter = float2(LaunchID.xy) + float2(0.5, 0.5);
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const float2 inUV = pixelCenter / float2(LaunchSize.xy);
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float2 d = inUV * 2.0 - 1.0;
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float4 target = mul(ubo.projInverse, float4(d.x, d.y, 1, 1));
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RayDesc rayDesc;
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rayDesc.Origin = mul(ubo.viewInverse, float4(0, 0, 0, 1)).xyz;
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rayDesc.Direction = mul(ubo.viewInverse, float4(normalize(target.xyz), 0)).xyz;
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rayDesc.TMin = 0.001;
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rayDesc.TMax = 10000.0;
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Payload payload;
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TraceRay(accelStruct, RAY_FLAG_FORCE_OPAQUE, 0xff, 0, 0, 0, rayDesc, payload);
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image[int2(LaunchID.xy)] = float4(payload.hitValue, 0.0);
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}
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[shader("closesthit")]
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void closesthitMain(inout Payload payload, in Attributes attribs)
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{
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uint PrimitiveID = PrimitiveIndex();
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int3 index = int3(indices[3 * PrimitiveID], indices[3 * PrimitiveID + 1], indices[3 * PrimitiveID + 2]);
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Vertex v0 = unpack(index.x);
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Vertex v1 = unpack(index.y);
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Vertex v2 = unpack(index.z);
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// Interpolate normal
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const float3 barycentricCoords = float3(1.0f - attribs.bary.x - attribs.bary.y, attribs.bary.x, attribs.bary.y);
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float3 normal = normalize(v0.normal * barycentricCoords.x + v1.normal * barycentricCoords.y + v2.normal * barycentricCoords.z);
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// Basic lighting
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float3 lightVector = normalize(ubo.lightPos.xyz);
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float dot_product = max(dot(lightVector, normal), 0.2);
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payload.hitValue = v0.color.rgb * dot_product;
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RayDesc rayDesc;
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rayDesc.Origin = WorldRayOrigin() + WorldRayDirection() * RayTCurrent();
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rayDesc.Direction = lightVector;
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rayDesc.TMin = 0.001;
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rayDesc.TMax = 100.0;
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payload.shadowed = true;
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// Offset indices to match shadow hit/miss index
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TraceRay(accelStruct, RAY_FLAG_ACCEPT_FIRST_HIT_AND_END_SEARCH | RAY_FLAG_FORCE_OPAQUE | RAY_FLAG_SKIP_CLOSEST_HIT_SHADER, 0xff, 0, 0, 1, rayDesc, payload);
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if (payload.shadowed) {
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payload.hitValue *= 0.3;
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}
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}
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[shader("miss")]
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void missMain(inout Payload payload)
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{
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payload.hitValue = float3(0.0, 0.0, 0.2);
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} |