HDRenderPipeline: Move ComputeTransmittance to commonMaterial.hlsl

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

 #endif
 }
 
-// Computes the fraction of light passing through the object.
-// N.b.: it is not just zero scattering (light traveling in a straight path)!
-// We derive the transmittance function from the SSS profile, by normalizing it s.t. R(0) = 1.
-// Ref: Approximate Reflectance Profiles for Efficient Subsurface Scattering by Pixar (BSSRDF only).
-float3 ComputeTransmittance(float3 S, float3 surfaceAlbedo, float thickness, float radiusScale)
-{
-    // Thickness and SSS radius are decoupled for artists.
-    // In theory, we should modify the thickness by the inverse of the radius scale of the profile.
-    // thickness /= radiusScale;
-
-    float3 expOneThird = exp(((-1.0 / 3.0) * thickness) * S);
-
-    return 0.5 * (expOneThird + expOneThird * expOneThird * expOneThird) * surfaceAlbedo;
-}
-
 void FillMaterialIdStandardData(float3 baseColor, float specular, float metallic, float roughness, float3 normalWS, float3 tangentWS, float anisotropy, inout BSDFData bsdfData)
 {
     bsdfData.diffuseColor = baseColor * (1.0 - metallic);

Assets/ScriptableRenderPipeline/HDRenderPipeline/SceneSettings/DrawTransmittanceGraph.shader

 
             #include "../../ShaderLibrary/Common.hlsl"
             #include "../../ShaderLibrary/Color.hlsl"
+            #include "../../ShaderLibrary/CommonMaterial.hlsl"
-            #define UNITY_MATERIAL_LIT // Needs to be defined before including Material.hlsl
-            #include "../Material/Material.hlsl"
 
             //-------------------------------------------------------------------------------------
             // Inputs & outputs

Assets/ScriptableRenderPipeline/ShaderLibrary/CommonMaterial.hlsl

     return float3(oneMinusT, oneMinusT, oneMinusT) + b * t;
 }
 
+// ----------------------------------------------------------------------------
+// SSS/Transmittance
+// ----------------------------------------------------------------------------
+
+// Computes the fraction of light passing through the object.
+// N.b.: it is not just zero scattering (light traveling in a straight path)!
+// We derive the transmittance function from the SSS profile, by normalizing it s.t. R(0) = 1.
+// Ref: Approximate Reflectance Profiles for Efficient Subsurface Scattering by Pixar (BSSRDF only).
+float3 ComputeTransmittance(float3 S, float3 surfaceAlbedo, float thickness, float radiusScale)
+{
+    // Thickness and SSS radius are decoupled for artists.
+    // In theory, we should modify the thickness by the inverse of the radius scale of the profile.
+    // thickness /= radiusScale;
+
+    float3 expOneThird = exp(((-1.0 / 3.0) * thickness) * S);
+
+    return 0.5 * (expOneThird + expOneThird * expOneThird * expOneThird) * surfaceAlbedo;
+}
+
 // MACRO from Legacy Untiy
 // Transforms 2D UV by scale/bias property
 #define TRANSFORM_TEX(tex, name) ((tex.xy) * name##_ST.xy + name##_ST.zw)