Refractored refraction keyword

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Editor/LitUI.cs

             SetKeyword(material, "_MATID_CLEARCOAT", materialId == Lit.MaterialId.LitClearCoat);
 
             var refractionModeValue = (Lit.RefractionMode)material.GetFloat(kRefractionMode);
-            SetKeyword(material, "_REFRACTION_THINPLANE", refractionModeValue == Lit.RefractionMode.ThinPlane);
-            SetKeyword(material, "_REFRACTION_THICKPLANE", refractionModeValue == Lit.RefractionMode.ThickPlane);
-            SetKeyword(material, "_REFRACTION_THICKSPHERE", refractionModeValue == Lit.RefractionMode.ThickSphere);
-
-            var hasRefraction = (!material.HasProperty(kPreRefractionPass) 
-                || material.GetFloat(kPreRefractionPass) <= 0.0)
-                && refractionModeValue != Lit.RefractionMode.None;
-            SetKeyword(material, "_REFRACTION_ON", hasRefraction); // Refraction is not available for pre refraction (color buffer cannot be fetched)
+            // We can't have refraction in pre-refraction queue
+            var canHaveRefraction = !material.HasProperty(kPreRefractionPass) || material.GetFloat(kPreRefractionPass) <= 0.0;
+            SetKeyword(material, "_REFRACTION_THINPLANE", (refractionModeValue == Lit.RefractionMode.ThinPlane) && canHaveRefraction);
+            SetKeyword(material, "_REFRACTION_THICKPLANE", (refractionModeValue == Lit.RefractionMode.ThickPlane) && canHaveRefraction);
+            SetKeyword(material, "_REFRACTION_THICKSPHERE", (refractionModeValue == Lit.RefractionMode.ThickSphere) && canHaveRefraction);
         }
     }
 } // namespace UnityEditor

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.hlsl

     #include "../../../Core/ShaderLibrary/VolumeRendering.hlsl"
 #endif
 
+// Define refraction keyword helpers
+#if defined(_REFRACTION_THINPLANE) || defined(_REFRACTION_THICKPLANE) || defined(_REFRACTION_THICKSPHERE)
+    #define HAS_REFRACTION
+#else
+    #undef HAS_REFRACTION
+#endif
+
 // In case we pack data uint16 buffer we need to change the output render target format to uint16
 // TODO: Is there a way to automate these output type based on the format declare in lit.cs ?
 #if SHADEROPTIONS_PACK_GBUFFER_IN_U16
     specularLighting = float3(0.0, 0.0, 0.0);
     weight = float2(0.0, 0.0);
 
-#if !defined(_REFRACTION_ON)
-    return;
-#endif
-
-#if defined(_REFRACTION_THINPLANE) || defined(_REFRACTION_THICKPLANE) || defined(_REFRACTION_THICKSPHERE)
+#ifdef HAS_REFRACTION
     // Refraction process:
     //  1. Depending on the shape model, we calculate the refracted point in world space and the optical depth
     //  2. We calculate the screen space position of the refracted point
     // Beer-Lamber law for absorption
     float3 transmittance = exp(-bsdfData.absorptionCoefficient * opticalDepth);
     diffuseLighting *= transmittance;
-
-#else
-    // Use perfect flat transparency when we cannot fetch the correct pixel color for the refracted point
-    diffuseLighting = SAMPLE_TEXTURE2D_LOD(_GaussianPyramidColorTexture, s_trilinear_clamp_sampler, posInput.positionSS, 0.0).rgb;
 #endif
 }
 

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.shader

     #pragma shader_feature _PIXEL_DISPLACEMENT_LOCK_OBJECT_SCALE
     #pragma shader_feature _VERTEX_WIND
     #pragma shader_feature _ _REFRACTION_THINPLANE _REFRACTION_THICKPLANE _REFRACTION_THICKSPHERE
-    #pragma shader_feature _REFRACTION_ON
 
     #pragma shader_feature _ _MAPPING_PLANAR _MAPPING_TRIPLANAR
     #pragma shader_feature _NORMALMAP_TANGENT_SPACE

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/LitDataInternal.hlsl

     surfaceData.specularColor *= SAMPLE_UVMAPPING_TEXTURE2D(_SpecularColorMap, sampler_SpecularColorMap, layerTexCoord.base).rgb;
 #endif
 
-#if defined(_REFRACTION_THINPLANE) || defined(_REFRACTION_THICKPLANE) || defined(_REFRACTION_THICKSPHERE)
+#ifdef HAS_REFRACTION
     surfaceData.ior = _IOR;
     surfaceData.transmittanceColor = _TransmittanceColor;
     surfaceData.atDistance = _ATDistance;

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/LitTessellation.shader

     #pragma shader_feature _VERTEX_WIND
     #pragma shader_feature _ _TESSELLATION_PHONG
     #pragma shader_feature _ _REFRACTION_THINPLANE _REFRACTION_THICKPLANE _REFRACTION_THICKSPHERE
-    #pragma shader_feature _REFRACTION_ON
 
     #pragma shader_feature _ _MAPPING_PLANAR _MAPPING_TRIPLANAR
     #pragma shader_feature _NORMALMAP_TANGENT_SPACE