HDRednerPipeline: Add some comment for surface gradient and normalize tangentWS now

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

             float3x3 worldToTangent = input.worldToTangent;
 
         #ifdef SURFACE_GRADIENT
+            // TODO: Check it is required to normalize, maybe it is ok ?
             // The TBN is not normalize, normalize it to do per pixel displacement
             worldToTangent[1] = normalize(worldToTangent[1]);
             worldToTangent[2] = normalize(worldToTangent[2]);
     surfaceData.perceptualSmoothness = SURFACEDATA_BLEND_SCALAR(surfaceData, perceptualSmoothness, weights);
     surfaceData.ambientOcclusion = SURFACEDATA_BLEND_SCALAR(surfaceData, ambientOcclusion, weights);
     surfaceData.metallic = SURFACEDATA_BLEND_SCALAR(surfaceData, metallic, weights);
-#ifdef SURFACE_GRADIENT
-    surfaceData.tangentWS = normalize(input.worldToTangent[0].xyz); // The tangent is not normalize in worldToTangent when using surface gradient
-#else
-    surfaceData.tangentWS = input.worldToTangent[0].xyz;
-#endif
+    surfaceData.tangentWS = normalize(input.worldToTangent[0].xyz); // The tangent is not normalize in worldToTangent for mikkt. TODO: Check if it expected that we normalize with Morten. Tag: SURFACE_GRADIENT
     // Init other parameters
     surfaceData.materialId = 1; // MaterialId.LitStandard
     surfaceData.anisotropy = 0;

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

     surfaceData.tangentWS = TransformObjectToWorldDir(tangentOS);
     #endif
 #else
-    #ifdef SURFACE_GRADIENT
-    surfaceData.tangentWS = normalize(input.worldToTangent[0].xyz); // The tangent is not normalize in worldToTangent when using surface gradient
-    #else
-    surfaceData.tangentWS = input.worldToTangent[0].xyz;
-    #endif
+    surfaceData.tangentWS = normalize(input.worldToTangent[0].xyz); // The tangent is not normalize in worldToTangent for mikkt. TODO: Check if it expected that we normalize with Morten. Tag: SURFACE_GRADIENT
 #endif
 
 #ifdef _ANISOTROPYMAP

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/MaterialUtilities.hlsl

 
     #ifdef SURFACE_GRADIENT
     // TOCHECK: seems that we don't need to invert any genBasisTB(), sign cancel. Which is expected as we deal with surface gradient.
+
+    // TODO: For surface gradient we must invert or mirror the normal just after the interpolation. It will allow to work with layered with all basis. Currently it is not the case
     #endif
 #endif
 }