Small fixes

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

                 ++EditorGUI.indentLevel;
 
                 var isPrePass = material.GetFloat(kPrePrefractionPass) > 0.0;
-                if (refractionMode != null && !isPrePass)
+                if (refractionMode != null
+                    // Refraction is not available for pre-refraction objects
+                    && !isPrePass)
                 {
                     m_MaterialEditor.ShaderProperty(refractionMode, Styles.refractionModeText);
                     var mode = (Lit.RefractionMode)refractionMode.floatValue;

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.hlsl

     }
 
     // Map the roughness to the correct mip map level of the color pyramid
-    float mipLevel = PerceptualRoughnessToMipmapLevel(bsdfData.perceptualRoughness);
+    float mipLevel = PerceptualRoughnessToMipmapLevel(bsdfData.perceptualRoughness, uint(_GaussianPyramidColorMipSize.z));
     diffuseLighting = SAMPLE_TEXTURE2D_LOD(_GaussianPyramidColorTexture, s_trilinear_clamp_sampler, refractedBackPointSS, mipLevel).rgb;
 
     // Beer-Lamber law for absorption