HDRenderPipeline: Fix normalization of normal map with SurfaceGradient/POM

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]);
-        #endif
-
+            // Note: The TBN is not normalize as it is based on mikkt. We should normalize it, but POM is always use on simple enough surfarce that mean it is not required (save 2 normalize). Tag: SURFACE_GRADIENT
             float3 viewDirTS = isPlanar ? float3(uvXZ, V.y) : TransformWorldToTangent(V, worldToTangent);
             NdotV = viewDirTS.z;
 
 
             float3x3 worldToTangent = input.worldToTangent;
 
-        #ifdef SURFACE_GRADIENT
-            // The TBN is not normalize, normalize it to do per pixel displacement
-            worldToTangent[1] = normalize(worldToTangent[1]);
-            worldToTangent[2] = normalize(worldToTangent[2]);
-        #endif
-
+            // Note: The TBN is not normalize as it is based on mikkt. We should normalize it, but POM is always use on simple enough surfarce that mean it is not required (save 2 normalize). Tag: SURFACE_GRADIENT
             // For planar the view vector is the world view vector (unless we want to support object triplanar ? and in this case used TransformWorldToObject)
             // TODO: do we support object triplanar ? See ComputeLayerTexCoord
             float3 viewDirTS = isPlanar ? float3(-V.xz, V.y) : TransformWorldToTangent(V, worldToTangent);
     surfaceData.perceptualSmoothness = SURFACEDATA_BLEND_SCALAR(surfaceData, perceptualSmoothness, weights);
     surfaceData.ambientOcclusion = SURFACEDATA_BLEND_SCALAR(surfaceData, ambientOcclusion, weights);
     surfaceData.metallic = SURFACEDATA_BLEND_SCALAR(surfaceData, metallic, weights);
-    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
+    surfaceData.tangentWS = normalize(input.worldToTangent[0].xyz); // The tangent is not normalize in worldToTangent for mikkt. Tag: SURFACE_GRADIENT
     // Init other parameters
     surfaceData.materialId = 1; // MaterialId.LitStandard
     surfaceData.anisotropy = 0;

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/MaterialUtilities.hlsl

     #ifdef SURFACE_GRADIENT
     normalWS = SurfaceGradientResolveNormal(input.worldToTangent[2], normalTS);
     #else
-    normalWS = TransformTangentToWorld(normalTS, input.worldToTangent);
+    // We need to normalize as we use mikkt tangent space and this is expected (tangent space is not normalize)
+    normalWS = normalize(TransformTangentToWorld(normalTS, input.worldToTangent));
     #endif
 
     // Orthonormalize the basis vectors using the Gram-Schmidt process.