Minor changes and commets on Standard Surface shader.

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/Lighting.hlsl

     SHCoefficients[5] = unity_SHBb;
     SHCoefficients[6] = unity_SHC;
 
-    return SampleSH9(SHCoefficients, normalWS);
+    return max(half3(0, 0, 0), SampleSH9(SHCoefficients, normalWS));
 }
 
 // SH Vertex Evaluation. Depending on target SH sampling might be
 #endif
 
     // Default: Evaluate SH fully per-pixel
-    return max(half3(0, 0, 0), SampleSH(normalWS));
+    return SampleSH(normalWS);
 }
 
 // Sample baked lightmap. Non-Direction and Directional if available.

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/LightweightPassLit.hlsl

     float fogFactor = IN.fogFactorAndVertexLight.x;
 
     half4 color = LightweightFragmentPBR(IN.posWS.xyz, normalWS, IN.viewDir, indirectDiffuse, IN.fogFactorAndVertexLight.yzw, surfaceData.albedo, surfaceData.metallic, surfaceData.specular, surfaceData.smoothness, surfaceData.occlusion, surfaceData.emission, surfaceData.alpha);
-
-    // Computes fog factor per-vertex
     ApplyFog(color.rgb, fogFactor);
     return color;
 }

ScriptableRenderPipeline/LightweightPipeline/LWRP/Shaders/LightweightStandard.shader

 
     SubShader
     {
+        // Lightweight Pipeline tag is required. If Lightweight pipeline is not set in the graphics settings
+        // this Subshader will fail. One can add a subshader below or fallback to Standard built-in to make this
+        // material work with both Lightweight Pipeline and Builtin Unity Pipeline
-        //  Base forward pass (directional light, emission, lightmaps, ...)
+        //  Forward pass. Shades all light in a single pass. GI + emission + Fog
+            // Lightmode matches the ShaderPassName set in LightweightPipeline.cs. SRPDefaultUnlit and passes with
+            // no LightMode tag are also rendered by Lightweight Pipeline
             Tags{"LightMode" = "LightweightForward"}
 
             Blend[_SrcBlend][_DstBlend]
-            // Required to compile gles 2.0 with standard srp library
+            // Required to compile gles 2.0 with standard SRP library
+            // All shaders must be compiled with HLSLcc and currently only gles is not using HLSLcc by default
             #pragma prefer_hlslcc gles
             #pragma target 3.0