This issue seems to happen when there is a relatively small piece that is separate topology from the main mesh. In this particular example, the issue was fixed by merging the gem topology with the rest of the mesh so the topology was connected. But now I am dealing with the same issue on a belt buckle that is not supposed to be connected. Adding even excessive resize points to the parametric outfit does not fix the issue.
Does anyone have a solution to this issue? I know from a recent unreal engine fest talk with marvelous designer that it is as of present NOT possible to use your own skinned weights with parametric resizeable outfits as the process will overwrite your existing weights. But this is frustrating, the client wants the whole asset parametric. This is the last thing to do keeping me from getting paid right now, I want to fix it ASAP.
I can’t see your skin weights, but this looks like the same cause as the gem case. The parametric outfit resize recomputes weights by projecting from the nearest body surface, and a small island with its own topology gets weights from whatever it happens to be closest to, so parts of it follow different bones.
Things worth trying:
Keep the buckle as a separate piece that is not part of the parametric garment. Export it as its own static mesh or skeletal mesh and attach it in the engine, either to a socket on the spine or pelvis bone or on a Leader Pose / Set Leader Pose Component setup, so it moves rigidly with one bone.
If it must stay in the garment, add a thin bridge of geometry (a strap or a few welded faces) that links the buckle to the belt. This is the same welded-topology fix you used for the gem, just hidden under the buckle.
Check that the buckle’s pivot and its vertices are inside the outfit’s resize region, not floating off the cloth. Islands far from the body surface get unpredictable weights.
After the outfit is built, open the skeletal mesh weight paint and inspect the buckle. If the bad weights are clearly wrong, a single bone assignment on the island is cleaner than more resize points.
Yes I’m aware of this limitation, I did mention it in my post. I considered the welded / connected faces approach, but this is a really janky undesirable solution I am considering only as a last case scenario. I would much prefer to be able to fix the issue directly. Having it attach to a socket doesn’t work, as the strap itself skins properly but the buckle does not, it would result in clipping. Also, that is not even close to a clean solution for parametric metahuman outfits which is what my client wants.
I considered breaking the buckle off into its own skeletal mesh / cloth asset and merging them together in the cloth collection of the outfit asset. Also not ideal by any means.
I would like you to clarify what you mean by “inside the resize region”. How do I check this? I am not given a lot of options in the resize outfit source overrides that I can play with to troubleshoot, at least the ones I am aware of.
Also, I am certain of the skinning issues because metahuman creator actually warns me about invalid skin weights in the dataflow. It actually comes up as big red text when this issue happens to one of my outfit assets.
