Fixed minor readability issues in the ray tracing code.

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -60,6 +60,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Moved AMD FidelityFX shaders to core
 - Improved sampling of overlapping point/area lights in path-traced volumetric scattering (case 1358777).
 - Path-traced volumetric scattering now takes fog color into account, adding scattered contribution on top of the non-scattered result (cases 1346105, 1358783).
+- Fixed minor readability issues in the ray tracing code.
 
 ## [12.0.0] - 2021-01-11
 

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Common/RayBinning.compute

@@ -6,7 +6,9 @@
 #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
 #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Color.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariables.hlsl"
+#include "Packages/com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariablesGlobal.cs.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/NormalBuffer.hlsl"
+#include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/RayTracingCommon.hlsl"
 
 #define RAY_BINNING_TILE_SIZE 16
 #define BINNING_TILE_SIZE 16
@@ -30,7 +32,7 @@ void RAY_BINNING(uint2 groupThreadId : SV_GroupThreadID, uint3 dispatchThreadId
     uint2 currentCoord = groupId * RAY_BINNING_TILE_SIZE + groupThreadId.xy;
 
     #if HALF_RESOLUTION
-    currentCoord *= 2;
+    currentCoord = ComputeSourceCoordinates(currentCoord, _RaytracingFrameIndex);
     #endif
 
     // Initialize the invalid counter to 0

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Deferred/RaytracingDeferred.compute

@@ -30,6 +30,7 @@
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/RaytracingLightLoop.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Common/AtmosphericScatteringRayTracing.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/RayTracingFallbackHierarchy.cs.hlsl"
+#include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/RayTracingCommon.hlsl"
 
 #define RAYTRACING_DEFERRED_TILE_SIZE 8
 
@@ -48,7 +49,7 @@ void RAYTRACING_DEFERRED(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 gro
     uint2 currentCoord = groupId * RAYTRACING_DEFERRED_TILE_SIZE + groupThreadId;
 
     #ifdef HALF_RESOLUTION
-    currentCoord *=2;
+    currentCoord = ComputeSourceCoordinates(currentCoord, _RaytracingFrameIndex);
     #endif
 
     // Initialize the output buffer
@@ -71,7 +72,7 @@ void RAYTRACING_DEFERRED(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 gro
 
     float3 finalColor = 0.0f;
     // if the distance is exactly zero, this means we are facing an environement ray that we need to evaluate
-    if (rayDistance == 0.0f)
+    if (RayTracingGBufferIsSky(rayDistance))
     {
         // Weight value used to do the blending
         float weight = 0.0;
@@ -96,7 +97,7 @@ void RAYTRACING_DEFERRED(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 gro
             finalColor = HsvToRgb(finalColor);
         }
     }
-    else if (rayDistance < 0.0f)
+    else if (RayTracingGBufferIsUnlit(rayDistance))
     {
         finalColor = LOAD_TEXTURE2D_X(_GBufferTexture3, currentCoord).rgb;
 
@@ -119,7 +120,7 @@ void RAYTRACING_DEFERRED(uint3 dispatchThreadId : SV_DispatchThreadID, uint2 gro
     }
 
     // If the distance is negative, this means it is a sky pixel or an unlit material
-    if (rayDistance <= 0.0f)
+    if (!RayTracingGBufferIsLit(rayDistance))
     {
         _RaytracingLitBufferRW[COORD_TEXTURE2D_X(currentCoord)] = float4(finalColor * (_RaytracingPreExposition ? 1.0 : GetInverseCurrentExposureMultiplier()), 0.0);
         return;

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/Deferred/RaytracingGBuffer.raytrace

@@ -58,7 +58,7 @@ uint _RayBinTileViewOffset;
 [shader("miss")]
 void MissShaderGBuffer(inout RayIntersectionGBuffer rayIntersection : SV_RayPayload)
 {
-    rayIntersection.t = 0;
+    rayIntersection.t = RAY_TRACING_DISTANCE_FLAG_SKY;
 }
 
 struct PixelCoordinates

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/RayTracingCommon.hlsl

@@ -57,4 +57,23 @@ uint2 ComputeSourceCoordinates(uint2 halfResCoord, int frameIndex)
 {
     return halfResCoord * 2;
 }
+
+// These need to be negative for RayDistanceIndicatesHitSkyOrUnlit
+#define RAY_TRACING_DISTANCE_FLAG_UNLIT -1.0
+#define RAY_TRACING_DISTANCE_FLAG_SKY 0.0
+
+bool RayTracingGBufferIsUnlit(float rayDistance)
+{
+    return rayDistance < 0.0;
+}
+
+bool RayTracingGBufferIsSky(float rayDistance)
+{
+    return rayDistance == RAY_TRACING_DISTANCE_FLAG_SKY;
+}
+
+bool RayTracingGBufferIsLit(float rayDistance)
+{
+    return rayDistance > 0.0;
+}
 #endif // RAY_TRACING_COMMON_HLSL

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/ShaderPass/ShaderPassRaytracingGBuffer.hlsl

@@ -48,7 +48,7 @@ void ClosestHitGBuffer(inout RayIntersectionGBuffer rayIntersectionGbuffer : SV_
 
     // Then export it to the gbuffer
     EncodeIntoStandardGBuffer(standardLitData, rayIntersectionGbuffer.gbuffer0, rayIntersectionGbuffer.gbuffer1, rayIntersectionGbuffer.gbuffer2, rayIntersectionGbuffer.gbuffer3);
-    rayIntersectionGbuffer.t = standardLitData.isUnlit != 0 ? -1 : RayTCurrent();
+    rayIntersectionGbuffer.t = standardLitData.isUnlit != 0 ? RAY_TRACING_DISTANCE_FLAG_UNLIT : RayTCurrent();
 }
 
 // Generic function that handles the reflection code