#ifdef VARYINGS_NEED_TANGENT_TO_WORLD
float4 tangentWS = float4(input.interpolators2.xyz, input.interpolators2.w > 0.0 ? 1.0 : -1.0);
// TODO: We should be able to not make distinction between the two path, but it mean material need to be aware to normalize the TBN when required, like for example for POM.
// For now do some test by keeping code consistent with previous visual.
#ifdef SURFACE_GRADIENT
// Normalize normalWS vector but keep the renormFactor to apply it to bitangent and tangent
float3 unnormalizedNormalWS = input.interpolators1.xyz;
float renormFactor = 1.0 / length(unnormalizedNormalWS);
// by uniformly scaling all 3 vectors since normalization of the perturbed normal will cancel it.
output.worldToTangent[0] = worldToTangent[0] * renormFactor;
output.worldToTangent[1] = worldToTangent[1] * renormFactor;
output.worldToTangent[2] = worldToTangent[2] * renormFactor;
float3 normalWS = output.worldToTangent[2];
#else
// TODO: Check if we must do like for surface gradient (i.e not normalize ?) For now, for consistency with previous code we normalize
// Normalize after the interpolation
float3 normalWS = normalize(input.interpolators1);
tangentWS.xyz = normalize(tangentWS.xyz);
// bitangent on the fly option in xnormal to reduce vertex shader outputs.
float3x3 worldToTangent = CreateWorldToTangent(normalWS, tangentWS.xyz, tangentWS.w);
output.worldToTangent[0] = worldToTangent[0];
output.worldToTangent[1] = worldToTangent[1];
output.worldToTangent[2] = worldToTangent[2];
#endif
output.worldToTangent[2] = worldToTangent[2] * renormFactor; // normalizes the interpolated vertex normal
#endif // VARYINGS_NEED_TANGENT_TO_WORLD
#ifdef VARYINGS_NEED_TEXCOORD0
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