Don't use thickness along the view dir for thin objects

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.hlsl

 
     uint transmissionMode = BitFieldExtract(_TransmissionFlags, 2, 2 * subsurfaceProfile);
 
-    bsdfData.enableTransmission = (_EnableSSS != 0) && (transmissionMode != SSS_TRSM_MODE_NONE);
+    bsdfData.enableTransmission = transmissionMode != SSS_TRSM_MODE_NONE;
     bsdfData.useThinObjectMode  = transmissionMode == SSS_TRSM_MODE_THIN;
 
     if (bsdfData.enableTransmission)

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/LitData.hlsl

     // Done one time for all layered - cumulate with spec occ alpha for now
     surfaceData.specularOcclusion *= GetHorizonOcclusion(V, surfaceData.normalWS, interpolatedVertexNormal, _HorizonFade);
 
-    // Convert thickness along the normal to thickness along the viewing direction.
-    surfaceData.thickness *= saturate(dot(interpolatedVertexNormal, V));
+    uint transmissionMode = BitFieldExtract(_TransmissionFlags, 2, 2 * surfaceData.subsurfaceProfile);
+
+    if (transmissionMode != SSS_TRSM_MODE_THIN)
+    {
+        // Convert thickness along the normal to thickness along the viewing direction.
+        surfaceData.thickness *= saturate(dot(interpolatedVertexNormal, V));
+    }
 
     // Caution: surfaceData must be fully initialize before calling GetBuiltinData
     GetBuiltinData(input, surfaceData, alpha, depthOffset, builtinData);