Fix box light attenuation

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

@@ -48,6 +48,7 @@ The version number for this package has increased due to a version update of a r
 - Fixed missing BeginCameraRendering call for custom render mode of a Camera.
 - Fixed LayerMask editor for volume parameters.
 - Fixed the condition on temporal accumulation in the reflection denoiser (case 1303504).
+- Fixed box light attenuation.
 
 ### Changed
 - Removed the material pass probe volumes evaluation mode.

com.unity.render-pipelines.high-definition/Runtime/Lighting/LightLoop/HDShadowLoop.hlsl

@@ -105,7 +105,6 @@ void ShadowLoopMin(HDShadowContext shadowContext, PositionInputs posInput, float
                     float3 L;
                     float4 distances; // {d, d^2, 1/d, d_proj}
                     GetPunctualLightVectors(posInput.positionWS, s_lightData, L, distances);
-                    float distToLight = (s_lightData.lightType == GPULIGHTTYPE_PROJECTOR_BOX) ? distances.w : distances.x;
                     float lightRadSqr = s_lightData.size.x;
                     if (distances.x < s_lightData.range &&
                         PunctualLightAttenuation(distances, s_lightData.rangeAttenuationScale, s_lightData.rangeAttenuationBias,
@@ -169,7 +168,6 @@ void ShadowLoopMin(HDShadowContext shadowContext, PositionInputs posInput, float
                     float3 L;
                     float4 distances; // {d, d^2, 1/d, d_proj}
                     GetPunctualLightVectors(posInput.positionWS, lightData, L, distances);
-                    float distToLight = (lightData.lightType == GPULIGHTTYPE_PROJECTOR_BOX) ? distances.w : distances.x;
                     float lightRadSqr = lightData.size.x;
                     float shadowP;
 

com.unity.render-pipelines.high-definition/Runtime/Lighting/PunctualLightCommon.hlsl

@@ -25,24 +25,11 @@ void GetPunctualLightVectors(float3 positionWS, LightData light, out float3 L, o
 
     if (light.lightType == GPULIGHTTYPE_PROJECTOR_BOX)
     {
-        L = -light.forward;
-
-        float dist = -dot(lightToSample, L);
+        float dist = distances.w;
         float distSq = dist * dist;
-        distances.y = distSq;
-        if (light.rangeAttenuationBias == 1.0) // Light uses range attenuation
-        {
-            float distRcp = rcp(dist);
-            distances.x = dist;
-            distances.z = distRcp;
-            ModifyDistancesForFillLighting(distances, light.size.x);
-        }
-        else // Light is directionnal
-        {
-            // Note we maintain distances.y as otherwise the windowing function will give wrong results.
-            // There won't be attenuation as the light attenuation scale and biases are set such that attenuation is prevented.
-            distances.xz = 1; // No distance or angle attenuation
-        }
+
+        L = -light.forward;
+        distances.xyz = float3(1.0f, distSq, 1.0);
     }
     else
     {