Skeletal Mesh has blocky hard edges all over its surface (screenshot attached)

I swear I’ve come across this issue before, but I can’t remember what the cause was or how to fix it. Basically, ugly hard-edged blocks are appearing all over my skeletal mesh, like so:

Through troubleshooting, I’ve narrowed down that…

  • It’s not a texture / normal map issue
    as the hard edges are visible even
    before applying a material
  • It’s not caused by poor UV mapping,
    as it is occurring inside cleanly
    mapped areas
  • There isn’t some sort of rogue UV set
    hidden in the file
  • There is no funky geometry hidden in
    the mesh
  • Normals are all facing the same
    direction, everything looks good with
    backface culling turned on in Maya
  • Tried unlocking the normals in Maya
    and softening the edges again
  • Tried multiple versions of the FBX
    exporter
  • The issue is only present in Unreal -
    the edges look fine upon reimporting
    the FBX into Maya
  • The issue does not occur when
    importing the file as a static mesh
    instead of skeletal mesh
  • Resetting the weight painting to the
    default weights does not fix the
    issue

All those things considered, I can only assume it has something to do with it being a skeletal mesh. I’ve ruled out all the normal suspects in terms of normals and UVs, so I’m not really sure what is causing this. Has anyone else ever experienced this before?

Just one other thing to check - have you tested deleting history/non deformer history in Maya before doing the export?
I have also seen this issue before but can’t recall what the resolution was.

Ahh good suggestion, that definitely seems like another likely culprit. Unfortunately that doesn’t seem to be the case this time. Tried it and no such luck.

Posting a sample FBX, and giving specifics of which engine version you are using and if it is a launcher or source code build might also help with replicating and diagnosing the cause if you can.

Aha! I solved the problem! Seems the issue was being caused by the Triangulate function in Maya’s FBX exporter. I tried an export with that option checked off and the nasty blocks all disappeared. (Funny, I always thought Unreal required models to be triangulated first, but I guess they work without it).

I seem to be learning that the less functions I have checked in the FBX exporter, the better the process goes. (Baking animations through the exporter was giving me troubles earlier). Still… it’s odd that I could only see the issue in Unreal and not when testing the FBX files in Maya. Anywho, this is solved as far as I’m concerned.