Many (20+) Empty Material ID created for Skeletal Mesh

Apparently there is a model in my project that has 29 material ID in the component page but NOT on the Skeletal Mesh editor.

The character actually has 3 material ID. I have reimported this to no avail.

Do you have any steps to reproduce the issue outside of your project or is it just in your project and the asset you’re having trouble with?

I’m still trying to check if it’s at all project related. or it could be an asset. will update you when i’m back later.

for now. what I know is that , it’s SkeletalMesh related , not actor/code/logic.
Whenever I use this skeletal mesh in any actor , same thing would happen. But skeletal mesh editor is still showing fine.

Okay , I attempted to investigate this further. And more strange voodoo ensue :

  1. I migrated the related asset to a new Blank project. Out of sudden , all the skeletal mesh become undiscoverable. ( note that I DID brought along the skeleton as well as I used the Migrate function )… I deleted textures and materials and I zipped it. Thre’s absolutely no way to make them appear in content browser. I’ve checked the folder with the original project it appears that the file size is same. link text

  2. I exported the FBX, and checked in max. still 3mat id. reimported… 29 material ID.
    I am uploading this as well.The file size is bigger than 5MB hence i’m uploading it on Gdrive.

here’s the FBX files.

Hi Tim Hobson,

Okay I think i might have figured the issue out.

The closest pattern i can see occurring here is that these are the mesh I repeatedly delete and re-import LOD. It seems this creates material ID that don’t really exist.

Hey Frozenfire

Looking in our system I found one that does just this with UE-1394.

From the look of it, the materials are just superficial and do not actually add any performance cost other than just being there. This is an issue with the reimport process though. At the moment it’s been backlogged, but I’m updating the community interest to see this one resolved.



We have got the same problem with all our skeletal meshes. This is because we have one big MultiSub Material in 3dsMax but the skeletal mesh is only a part of the bigger object, thus only using a few of the material IDs.
I haven’t checked the draw calls in an empty scene but I do hope that this does not affect performance. Btw. we have one skeletal mesh with 400+ material slots when thrown into the scene. But “only” has 14 in the skeletal mesh editor.
Tim, can you confirm that this is just a display problem from the UE editor?

This was fixed in 4.13.

The bug description is talking about LOD1 re-import. But the general behaviour is still buggy. I can reproducibly import skeletal meshes with LOD0 having the problem of the skeletal mesh editor showing only used materials while dropped in the scene, it shows all referenced materials.
Also i noticed a problem with the material slots. Wanting to create a dynamic material instance for Slot 5 to change the texture parameter, the actual slot ID could be 34, or 56, because it is assuming the “superficial” material IDs!
Also, the root problem of this thread was never talking about LOD1. There seems to be a confusion here!

The reimport process was causing the material id’s to replicate based on the OPs steps and issue. That much has been fixed in 4.13.

If you try in 4.13 and still have the same issue post as a new question and include the steps that can reproduce the issue, please.

Thank you!

Tim, I will post a new question. Didn’t see the OPs comment! :slight_smile: You know I love FBX-import-bugs :smiley: :wink:

Just as much as I do. haha

See here please :slight_smile:

Thanks! I assigned myself. I’ll look into it soon.