weird conversion issue

[juliangums]

Looks like the model gets messed up somehow.
here the model as it appears in and online viewer. Looks very much like in SketchUp:

now loaded by mapbox after conversion

What am I doing wrong?

[kekscom]

You could check whether your OBJ file is triangulated.
Otherwise, without sample files and/or a test application there is very little chance of help.

[juliangums]

Just using the normal Mapbox GL

test.zip

[kekscom]

What I thought, faces are not triangulated. You need to do that first.
Usually when saving an OBJ file.

[juliangums]

That did work! Amazing! Dankeschön!

[juliangums]

Sry to bother you again, but I'm stuck. Any idea why this triangulated file takes infinitely long to convert?
model.zip

[kekscom]

This time it's hard to tell.
Perhaps it is about size, in terms of number of vertices and also extent of contained meshes.
Could you try to split this into smaller chunks and retest?