Some factor and comment of commonMaterial.hlsl

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/BSDF.hlsl

     return nf0 / (1.0 - f0);
 }
 
+// same as regular refract except there is not the test for total internal reflection + the vector is flipped for processing
+real3 CoatRefract(real3 X, real3 N, real ieta)
+{
+    real XdotN = saturate(dot(N, X));
+    return ieta * X + (sqrt(1 + ieta * ieta * (XdotN * XdotN - 1)) - ieta * XdotN) * N;
+}
+
 //-----------------------------------------------------------------------------
 // Specular BRDF
 //-----------------------------------------------------------------------------

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/CommonMaterial.hlsl

     return sqrt(2.0 / (variance + 2.0));
 }
 
-// same as regular refract except there is not the test for total internal reflection + the vector is flipped for processing
-real3 CoatRefract(real3 X, real3 N, real ieta)
+// ----------------------------------------------------------------------------
+// Helper for Disney parametrization
+// ----------------------------------------------------------------------------
+
+float3 ComputeDiffuseColor(float3 baseColor, float metallic)
-    real XdotN = saturate(dot(N, X));
-    return ieta * X + (sqrt(1 + ieta * ieta * (XdotN * XdotN - 1)) - ieta * XdotN) * N;
+    return baseColor * (1.0 - metallic);
+}
+
+float3 ComputeFresnel0(float3 baseColor, float metallic, float dielectricF0)
+{
+    return lerp(dielectricF0.xxx, baseColor, metallic);
-// Parallax mapping
+// Helper for normal blending
 // ----------------------------------------------------------------------------
 
 // ref https://www.gamedev.net/topic/678043-how-to-blend-world-space-normals/#entry5287707
     return normalize(real3(n1.xy * n2.z + n2.xy * n1.z, n1.z * n2.z));
 }
 
+// ----------------------------------------------------------------------------
+// Helper for triplanar
+// ----------------------------------------------------------------------------
+
 // Ref: http://http.developer.nvidia.com/GPUGems3/gpugems3_ch01.html / http://www.slideshare.net/icastano/cascades-demo-secrets
 real3 ComputeTriplanarWeights(real3 normal)
 {
     uvZY = float2(position.z, position.y);
 }
 
+// ----------------------------------------------------------------------------
+// Helper for detail map operation
+// ----------------------------------------------------------------------------
+
 real LerpWhiteTo(real b, real t)
 {
     real oneMinusT = 1.0 - t;
     real oneMinusT = 1.0 - t;
     return real3(oneMinusT, oneMinusT, oneMinusT) + b * t;
 }
-
 
 #endif // UNITY_COMMON_MATERIAL_INCLUDED

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.hlsl

     return ((featureFlags & flag) != 0);
 }
 
-float3 ComputeDiffuseColor(float3 baseColor, float metallic)
-{
-    return baseColor * (1.0 - metallic);
-}
-
-float3 ComputeFresnel0(float3 baseColor, float metallic, float dielectricF0)
-{
-    return lerp(dielectricF0.xxx, baseColor, metallic);
-}
-
 // Assume that bsdfData.diffusionProfile is init
 void FillMaterialSSS(uint diffusionProfile, float subsurfaceMask, inout BSDFData bsdfData)
 {