Raytracing tail call hello world

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingHelloWorld/Raytracing.hlsl

@@ -21,7 +21,7 @@ ConstantBuffer<RayGenConstantBuffer> g_rayGenCB : register(b0);
 typedef BuiltInTriangleIntersectionAttributes MyAttributes;
 struct RayPayload
 {
-    float4 color;
+    uint2 dispatchRayIndex;
 };
 
 bool IsInsideViewport(float2 p, Viewport viewport)
@@ -53,11 +53,8 @@ void MyRaygenShader()
         // TMin should be kept small to prevent missing geometry at close contact areas.
         ray.TMin = 0.001;
         ray.TMax = 10000.0;
-        RayPayload payload = { float4(0, 0, 0, 0) };
+        RayPayload payload = { uint2(DispatchRaysIndex().xy) };
         TraceRay(Scene, RAY_FLAG_CULL_BACK_FACING_TRIANGLES, ~0, 0, 1, 0, ray, payload);
-
-        // Write the raytraced color to the output texture.
-        RenderTarget[DispatchRaysIndex().xy] = payload.color;
     }
     else
     {
@@ -70,13 +67,15 @@ void MyRaygenShader()
 void MyClosestHitShader(inout RayPayload payload, in MyAttributes attr)
 {
     float3 barycentrics = float3(1 - attr.barycentrics.x - attr.barycentrics.y, attr.barycentrics.x, attr.barycentrics.y);
-    payload.color = float4(barycentrics, 1);
+    // Write the raytraced color to the output texture.
+    RenderTarget[payload.dispatchRayIndex.xy] = float4(barycentrics, 1);
 }
 
 [shader("miss")]
 void MyMissShader(inout RayPayload payload)
 {
-    payload.color = float4(0, 0, 0, 1);
+    // Write the raytraced color to the output texture.
+    RenderTarget[payload.dispatchRayIndex.xy] = float4(0.0, 0.0, 0.0, 1.0);
 }
 
 #endif // RAYTRACING_HLSL