Fixed a bug in the sphere-aabb light cluster (case 1294767).

com.unity.render-pipelines.core/ShaderLibrary/GeometricTools.hlsl

@@ -182,6 +182,15 @@ bool IntersectRayCone(float3 rayOrigin,  float3 rayDirection,
     return hit;
 }
 
+bool IntersectSphereAABB(float3 position, float radius, float3 aabbMin, float3 aabbMax)
+{
+  float x = max(aabbMin.x, min(position.x, aabbMax.x));
+  float y = max(aabbMin.y, min(position.y, aabbMax.y));
+  float z = max(aabbMin.z, min(position.z, aabbMax.z));
+  float distance2 = ((x - position.x) * (x - position.x) + (y - position.y) * (y - position.y) + (z - position.z) * (z - position.z));
+  return distance2 < radius * radius;
+}
+
 //-----------------------------------------------------------------------------
 // Miscellaneous functions
 //-----------------------------------------------------------------------------

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

@@ -31,6 +31,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed AOV api in render graph (case 1296605)
 - Fixed a small discrepancy in the marker placement in light intensity sliders (case 1299750)
 - Fixed issue with VT resolve pass rendergraph errors when opaque and transparent are disabled in frame settings.
+- Fixed a bug in the sphere-aabb light cluster (case 1294767).
 
 ### Changed
 - Removed the material pass probe volumes evaluation mode.

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/HDRaytracingLightCluster.cs

@@ -323,15 +323,19 @@ void BuildGPULightVolumes(HDCamera hdCamera, HDRayTracingLights rayTracingLights
             {
                 HDProbe currentEnvLight = rayTracingLights.reflectionProbeArray[lightIdx];
 
-                // Compute the camera relative position
-                Vector3 probePositionRWS = currentEnvLight.influenceToWorld.GetColumn(3);
-                if (ShaderConfig.s_CameraRelativeRendering != 0)
-                {
-                    probePositionRWS -= hdCamera.camera.transform.position;
-                }
 
                 if (currentEnvLight != null)
                 {
+                    // If the reflection probe is disabled, we should not be adding it
+                    if (!currentEnvLight.enabled) continue;
+
+                    // Compute the camera relative position
+                    Vector3 probePositionRWS = currentEnvLight.influenceToWorld.GetColumn(3);
+                    if (ShaderConfig.s_CameraRelativeRendering != 0)
+                    {
+                        probePositionRWS -= hdCamera.camera.transform.position;
+                    }
+
                     if (currentEnvLight.influenceVolume.shape == InfluenceShape.Sphere)
                     {
                         m_LightVolumesCPUArray[lightIdx + indexOffset].shape = 0;

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

@@ -8,6 +8,7 @@
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariables.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/HDRaytracingLightCluster.cs.hlsl"
 #include "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/ShaderVariablesRaytracingLightLoop.hlsl"
+#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/GeometricTools.hlsl"
 
 #define CLUSTER_GROUP_SIZE 8
 
@@ -78,27 +79,8 @@ void RaytracingLightCluster(uint3 threadID : SV_GroupThreadID, uint3 groupId : S
 
         if (currentLight.shape == 0)
         {
-            // When the shape we are processing is a sphere, the radius is stored in the three channels
-            float squareRange = currentLight.range.x * currentLight.range.x;
-
-            // So basically we need to flag this cell if one of the corners of the cell happens to be in the sphere
-            for(uint cIdx = 0; cIdx < 8; ++cIdx)
-            {
-                // Check if this corner is inside the shphere
-                float3 dir = currentLight.position - (cellCenterPosition + CornerSubDirections[cIdx] * _ClusterCellSize);
-                if(dot(dir, dir) <= squareRange)
-                {
-                    intersects = true;
-                    break;
-                }
-            }
-
-            // One additional case that we need to check is: Is the light inside the cell?
-            if (!intersects)
-            {
-                float3 distanceToCenter = abs(cellCenterPosition - currentLight.position) * 2.0;
-                intersects = (distanceToCenter.x < _ClusterCellSize.x) && (distanceToCenter.y < _ClusterCellSize.y) && (distanceToCenter.z < _ClusterCellSize.z);
-            }
+            // Do a box sphere intersection
+            intersects = IntersectSphereAABB(currentLight.position, currentLight.range.x, cellCenterPosition + CornerSubDirections[0] * _ClusterCellSize, cellCenterPosition + CornerSubDirections[7] * _ClusterCellSize);
         }
         else
         {