Disable refraction for pre-transparents

SampleScenes/HDTest/GraphicTest/Common/Material/Mat_refraction_thicksphere_EarthMap_pretransparent.mat

   m_Name: Mat_refraction_thicksphere_EarthMap_pretransparent
   m_Shader: {fileID: 4800000, guid: 6e4ae4064600d784cac1e41a9e6f2e59, type: 3}
   m_ShaderKeywords: _ALPHACUTOFFENABLE_OFF _BLENDMODE_LERP _MASKMAP _NORMALMAP_TANGENT_SPACE
-    _REFRACTION_ON _REFRACTION_THICKSPHERE _ROUGH_REFRACTION _ROUGH_REFRACTION_ON
+    _REFRACTION_THICKSPHERE _ROUGH_REFRACTION _ROUGH_REFRACTION_ON
   m_LightmapFlags: 1
   m_EnableInstancingVariants: 0
   m_DoubleSidedGI: 0
     - _ZTestMode: 8
     - _ZWrite: 0
     m_Colors:
-    - _BaseColor: {r: 1, g: 1, b: 1, a: 1}
+    - _BaseColor: {r: 1, g: 1, b: 1, a: 0.428}
     - _Color: {r: 1, g: 1, b: 1, a: 1}
     - _DoubleSidedConstants: {r: 1, g: 1, b: -1, a: 0}
     - _EmissionColor: {r: 0, g: 0, b: 0, a: 1}

ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipeline.cs

                 // Do a depth pre-pass for transparent objects that want it that will fill the depth buffer to reduce the overdraw (typical usage is hair rendering)
                 RenderTransparentDepthPrepass(m_CullResults, camera, renderContext, cmd);
 
-                cmd.Blit(m_CameraColorBufferRT, m_GaussianPyramidColorBuffer);
-
                 // Render pre transparent objects
                 RenderForward(m_CullResults, camera, renderContext, cmd, ForwardPass.PreTransparent);
                 RenderForwardError(m_CullResults, camera, renderContext, cmd, ForwardPass.PreTransparent);
                 cmd.ClearRenderTarget(false, true, Color.clear);
 
                 // Only transparent object can render distortion vectors
+                RenderTransparentRenderList(cullResults, camera, renderContext, cmd, HDShaderPassNames.s_DistortionVectorsName, preTransparentQueue:true);
                 RenderTransparentRenderList(cullResults, camera, renderContext, cmd, HDShaderPassNames.s_DistortionVectorsName);
             }
         }

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

             }
 
             var isPrePass = material.GetFloat(kTransparentPrepass) > 0.0;
-            SetKeyword(material, "_REFRACTION_ROUGHNESS_ON", !isPrePass); // Rough refraction is not available for pre transparent
+            SetKeyword(material, "_REFRACTION_ON", !isPrePass); // Refraction is not available for pre transparent (color buffer cannot be fetched)
         }
 
         static public void SetupBaseLitMaterialPass(Material material)

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

                 EditorGUILayout.LabelField(StylesBaseUnlit.TransparencyInputsText, EditorStyles.boldLabel);
                 ++EditorGUI.indentLevel;
 
-                if (refractionMode != null)
+                var isPrePass = material.GetFloat(kTransparentPrepass) > 0.0;
+                if (refractionMode != null && !isPrePass)
                 {
                     m_MaterialEditor.ShaderProperty(refractionMode, Styles.refractionModeText);
                     var mode = (Lit.RefractionMode)refractionMode.floatValue;

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.hlsl

     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)
     // Refraction process:
     //  1. Depending on the shape model, we calculate the refracted point in world space and the optical depth
         return;
     }
 
-#ifdef _REFRACTION_ROUGHNESS_ON
-    float mipLevel = PerceptualRoughnessToMipmapLevel(bsdfData.perceptualRoughness, uint(_GaussianPyramidColorMipSize.z));
+    float mipLevel = PerceptualRoughnessToMipmapLevel(bsdfData.perceptualRoughness);
-#else
-    diffuseLighting = SAMPLE_TEXTURE2D_LOD(_GaussianPyramidColorTexture, s_trilinear_clamp_sampler, refractedBackPointSS.xy, 0.0).rgb;
-#endif
 
     // Beer-Lamber law for absorption
     float3 transmittance = exp(-bsdfData.absorptionCoefficient * opticalDepth);

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_ROUGHNESS_ON
+    #pragma shader_feature _REFRACTION_ON
 
     #pragma shader_feature _ _MAPPING_PLANAR _MAPPING_TRIPLANAR
     #pragma shader_feature _NORMALMAP_TANGENT_SPACE