Clean up

ScriptableRenderPipeline/Core/ShaderLibrary/VolumeRendering.hlsl

 #endif
 
 float4 GetInScatteredRadianceAndTransmittance(float2 positionSS, float depthVS,
-                                              TEXTURE3D(VBufferLighting), SAMPLER3D(sampler_LinearXY_PointZ_Clamp),
+                                              TEXTURE3D(VBufferLighting), SAMPLER3D(linearClampSampler),
                                               float4 VBufferDepthEncodingParams, float2 VBufferScale)
 {
     int   n = VBUFFER_SLICE_COUNT;
     float2 uv = positionSS * VBufferScale;
 
     // Perform 2 bilinear taps. The sampler should clamp the values at the boundaries of the 3D texture.
-    float4 v0 = SAMPLE_TEXTURE3D_LOD(VBufferLighting, sampler_LinearXY_PointZ_Clamp, float3(uv, d0), 0);
-    float4 v1 = SAMPLE_TEXTURE3D_LOD(VBufferLighting, sampler_LinearXY_PointZ_Clamp, float3(uv, d1), 0);
+    float4 v0 = SAMPLE_TEXTURE3D_LOD(VBufferLighting, linearClampSampler, float3(uv, d0), 0);
+    float4 v1 = SAMPLE_TEXTURE3D_LOD(VBufferLighting, linearClampSampler, float3(uv, d1), 0);
     float4 vt = lerp(v0, v1, saturate((z - z0) / (z1 - z0)));
 
     return float4(vt.rgb, Transmittance(vt.a));

ScriptableRenderPipeline/HDRenderPipeline/Lighting/Deferred.shader

                 float4 volumetricLighting = GetInScatteredRadianceAndTransmittance(posInput.positionSS,
                                                                                    posInput.depthVS,
                                                                                    _VBufferLighting,
-                                                                                   s_linear_clamp_sampler, // TODO: use the right sampler
+                                                                                   s_linear_clamp_sampler,
                                                                                    _VBufferDepthEncodingParams,
                                                                                    _VBufferResolutionAndScale.zw);
                 diffuseLighting  *= volumetricLighting.a;

ScriptableRenderPipeline/HDRenderPipeline/Lighting/TilePass/Deferred.compute

     float4 volumetricLighting = GetInScatteredRadianceAndTransmittance(posInput.positionSS,
                                                                        posInput.depthVS,
                                                                        _VBufferLighting,
-                                                                       s_linear_clamp_sampler, // TODO: use the right sampler
+                                                                       s_linear_clamp_sampler,
                                                                        _VBufferDepthEncodingParams,
                                                                        _VBufferResolutionAndScale.zw);
     diffuseLighting  *= volumetricLighting.a;

ScriptableRenderPipeline/HDRenderPipeline/Lighting/Volumetrics/Resources/VolumetricLighting.compute

     float4 depthParams  = _VBufferDepthEncodingParams;
 
     float z0 = depthParams.x;              // View space Z coordinate of the near plane
-    float t0 = z0 * cameraRay.ratioLenToZ; // Distance to the near plane
+    float t0 = cameraRay.ratioLenToZ * z0; // Distance to the near plane
     float de = rcp(VBUFFER_SLICE_COUNT);   // Log-encoded distance between slices
 
     float3 totalRadiance = 0;
     {
         float e1 = s * de + de; // (s + 1) / sliceCount
         float z1 = DecodeLogarithmicDepth(e1, depthParams);
-        float t1 = z1 * cameraRay.ratioLenToZ;
+        float t1 = cameraRay.ratioLenToZ * z1;
-        float z = t * cameraRay.ratioZtoLen;
+        float z = cameraRay.ratioZtoLen * t;
         float3 positionWS = cameraRay.originWS + t * cameraRay.directionWS;
 
         // Get volume properties at 't'.
                     intensity *= lerp(1, shadow, lightData.shadowDimmer);
                 }
 
-                // Projector lights always have a cookies, so we can perform clipping inside the if().
+                // Projector lights always have cookies, so we can perform clipping inside the if().
                 [branch] if (lightData.cookieIndex >= 0)
                 {
                     float4 cookie = EvaluateCookie_Punctual(context, lightData, lightToSample);