Investigate why we can load gltf from polyhaven, but fbx have a problem with bump_normals

[Adnn]

For both gltf and fbx, the files does not contain tangent/bitangent and they are computed by Assimp.

The issue looks a bit like an handedness problem, but It is strange it is only the case with one format.

Tangents

FBX	glTF

Bitangents

FBX	glTF

[Adnn]

Well, as we can see above both formats lead to the same tangent/bitangent.

Turns out it was not an issue of handedness, but how I converted the exr normal map to png. Downloading the png directly from polyhaven fixed it.