Added SHADER_HINT_NICE_QUALITY. Viewdirection is normalized in vertex or frag depending on the quality hint.

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/Core.hlsl

 #include "CoreRP/ShaderLibrary/Packing.hlsl"
 #include "Input.hlsl"
 
+#if !defined(SHADER_HINT_NICE_QUALITY)
+#ifdef SHADER_API_MOBILE
+#define SHADER_HINT_NICE_QUALITY 0
+#else
+#define SHADER_HINT_NICE_QUALITY 1
+#endif
+#endif
+
 ///////////////////////////////////////////////////////////////////////////////
 #ifdef _NORMALMAP
     #define OUTPUT_NORMAL(IN, OUT) OutputTangentToWorld(IN.tangent, IN.normal, OUT.tangent, OUT.binormal, OUT.normal)

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/LightweightPassLit.hlsl

     inputData.normalWS = normalize(IN.normal);
 #endif
 
-#ifdef SHADER_API_MOBILE
-    // viewDirection should be normalized here, but we avoid doing it as it's close enough and we save some ALU.
-    inputData.viewDirectionWS = IN.viewDir;
+#if SHADER_HINT_NICE_QUALITY
+    inputData.viewDirectionWS = SafeNormalize(IN.viewDir);
-    inputData.viewDirectionWS = normalize(IN.viewDir);
+    // View direction is already normalize in vertex. Small acceptable error to save ALU.
+    inputData.viewDirectionWS = IN.viewDir;
 #endif
 
     inputData.shadowCoord = IN.shadowCoord;
 
     o.posWS = TransformObjectToWorld(v.vertex.xyz);
     o.clipPos = TransformWorldToHClip(o.posWS);
-    o.viewDir = SafeNormalize(GetCameraPositionWS() - o.posWS);
+
+    o.viewDir = GetCameraPositionWS() - o.posWS;
+
+#if !SHADER_HINT_NICE_QUALITY
+    // Normalize in vertex and avoid renormalizing it in frag to save ALU.
+    o.viewDir = SafeNormalize(o.viewDir);
+#endif
 
     // initializes o.normal and if _NORMALMAP also o.tangent and o.binormal
     OUTPUT_NORMAL(v, o);