Removed contact shadows on light transmission

com.unity.render-pipelines.high-definition/HDRP/Lighting/LightEvaluation.hlsl

 void EvaluateLight_Punctual(LightLoopContext lightLoopContext, PositionInputs posInput,
                             LightData lightData, BakeLightingData bakeLightingData,
                             float3 N, float3 L, float3 lightToSample, float4 distances,
-                            out float3 color, out float attenuation)
+                            out float3 color, out float attenuation, out float attenuationWithoutContactShadows)
 {
     float3 positionWS    = posInput.positionWS;
     float  shadow        = 1.0;
         // TODO: make projector lights cast shadows.
         shadow = GetPunctualShadowAttenuation(lightLoopContext.shadowContext, positionWS, N, lightData.shadowIndex, L, distances.x, posInput.positionSS);
         contactShadow = GetContactShadow(lightLoopContext, lightData.contactShadowIndex);
-        shadow = min(shadow, contactShadow);
 
 #ifdef SHADOWS_SHADOWMASK
         // Note: Legacy Unity have two shadow mask mode. ShadowMask (ShadowMask contain static objects shadow and ShadowMap contain only dynamic objects shadow, final result is the minimun of both value)
 #else
         shadow = lerp(1.0, shadow, lightData.shadowDimmer);
 #endif
+
+        attenuationWithoutContactShadows = attenuation * shadow;
+        
+        shadow = min(shadow, contactShadow);
     }
 
     attenuation *= shadow;

com.unity.render-pipelines.high-definition/HDRP/Lighting/Volumetrics/VolumetricLighting.compute

                     float4 distances     = float4(dist, distSq, distRcp, distProj);
                     float3 L             = -lightToSample * distRcp;
 
-                    float3 color; float attenuation;
+                    float3 color; float attenuation; float attenuationWithoutContactShadow;
-                                           0, L, lightToSample, distances, color, attenuation);
+                                           0, L, lightToSample, distances, color,
+                                           attenuation, attenuationWithoutContactShadow);
 
                     // Important:
                     // Ideally, all scattering calculations should use the jittered versions
                     float  distProj      = dot(lightToSample, light.forward);
                     float4 distances     = float4(1, 1, 1, distProj);
 
-                    float3 color; float attenuation;
+                    float3 color; float attenuation; float attenuationWithoutContactShadow;
-                                           0, L, lightToSample, distances, color, attenuation);
+                                           0, L, lightToSample, distances, color,
+                                           attenuation, attenuationWithoutContactShadow);
 
                     // Important:
                     // Ideally, all scattering calculations should use the jittered versions

com.unity.render-pipelines.high-definition/HDRP/Material/Lit/Lit.hlsl

 
     float3 color;
     float attenuation;
+    float attenuationWithoutContactShadow;
-                           lightToSample, distances, color, attenuation);
+                           lightToSample, distances, color, attenuation, attenuationWithoutContactShadow);
 
     // Restore the original shadow index.
     lightData.shadowIndex = originalShadowIndex;
         // Note: we do not modify the distance to the light, or the light angle for the back face.
         // This is a performance-saving optimization which makes sense as long as the thickness is small.
         // We use diffuse lighting for accumulation since it is going to be blurred during the SSS pass.
-        lighting.diffuse += EvaluateTransmission(bsdfData, transmittance, NdotL, NdotV, LdotV, attenuation * lightData.diffuseScale);
+        lighting.diffuse += EvaluateTransmission(bsdfData, transmittance, NdotL, NdotV, LdotV, attenuationWithoutContactShadow * lightData.diffuseScale);
     }
 
     // Save ALU by applying light and cookie colors only once.

com.unity.render-pipelines.high-definition/HDRP/Material/StackLit/StackLit.hlsl

 
     float3 color;
     float attenuation;
+    float attenuationWithoutContactShadow;
-                           lightToSample, distances, color, attenuation);
+                           lightToSample, distances, color, attenuation, attenuationWithoutContactShadow);
 
     // Restore the original shadow index.
     lightData.shadowIndex = originalShadowIndex;
         // Note: we do not modify the distance to the light, or the light angle for the back face.
         // This is a performance-saving optimization which makes sense as long as the thickness is small.
         // We use diffuse lighting for accumulation since it is going to be blurred during the SSS pass.
-        lighting.diffuse += EvaluateTransmission(bsdfData, transmittance, NdotL, NdotV, LdotV, attenuation * lightData.diffuseScale);
+        lighting.diffuse += EvaluateTransmission(bsdfData, transmittance, NdotL, NdotV, LdotV, attenuationWithoutContactShadow * lightData.diffuseScale);
     }
 
     // Save ALU by applying light and cookie colors only once.