Exporting a skeletal mesh and then importing that fbx results in broken visuals.

[Gsep]

Hello. My eventual goal is to be able to do a round trip with a skeletal mesh from unreal engine, through DCC to make edits and back to unreal.

Right now, i have simplified that down to exporting the skeletal mesh from unreal, and importing that same file again immediately without involving a dcc application. It’s not working right even before we involve other applications.

Specifically, I am working with face_mesh skeletal mesh asset from a metahuman, imported via quixel bridge, authored with metahuman creator.

If you want to replicate the problem, export the skeletal mesh to fbx, and then import that FBX.

With materials applied correctly, the mesh looks wrong. it seems to be the mesh normals.

There are no options for those on export. on import, the options available have no effect.

I am at a loss as to how to proceed. exporting a metahuman’s skeletal meshes to fbx and importing that fbx results in a broken visual; wrongly lit, versus the original.

Please help,

thank you.

[Uno1982]

Same issue if the fbx skeletal mesh has UV’s you’ll notice the exporter tears the mesh along the UV island. If you reimport without any changes you’ll see a seam form where those UV islands are thus destroying the export import workflow … you can kind of work around this by forcing the dialog and also ticking the import normals and tangents which will fix the seam issue in unreal but this does nothing to fix the vertex tearing that appears to have been introduced around 4.26 by the fbx exporter. Once in blender or maya your forced to work around the newly created islands or you can completely destroy the normals by “merging verts by distance” to get back to some form of decent modeling workflow. Sadly in its current state if you don’t have the source fbx its really difficult to export and work with an fbx export from unreal.