Non triangulated simple meshes with morph targets get morphs messed up after import

Let’s say you’ve got a simple cube with 8 vertices. You create a morph target with the top right vertices dragged outwards. If you don’t triangulate the mesh before importing this mesh into UE4 you will end up with the morph target vertices going in another direction. Triangulated before import it works fine.
(using Blender)

edit: updated version with more “normal” buggy results, quad mesh exported first and then triangulated

old .fbxs

Hey cyaceu,

I haven’t really encountered this with any other meshes, but maybe it’s something with how simple the geometry is. I recreated the assets in Maya just to make sure it wasn’t something about the blender exporter and I was able to reproduce it. I’ve entered UE-45696. You can track the report’s status as the issue is reviewed by our development staff. Please be aware that this issue may not be prioritized or fixed soon.