Rigging: Divided character mesh parts?

[Anonymous]

Hello community,

I'm pretty new to Maya but already got my hands on rigging and enjoying it.
For my project in Unity I need to rig a character that has to change clothes in runtime. So if the character is naked for example, and I want to wear shoes, the foot mesh of the character will be replaced by the foot to save performance when wearing several parts of equipment. The clothes meshes I got are perfectly fitting to the character mesh and stick exactly to the position of the character parts when wearing.
So my question is basically, if I have a character mesh with several parts, such as head, chest, upper arm, lower arm, legs etc. how can I rig it properly that the single mesh parts of the character won't get divided while rotating?
For example: If I move the LowerArm it shouldn't divide from the UpperArm.

Thanks for your time.
Best regards

[zewt]

That can be a bit tricky.  Assuming you're just using simple skinning, you need to make sure that the corresponding vertices on each part have exactly the same weight as their neighboring part for each joint.

I don't have any formula for this, but I'd create a merged master mesh, with all body parts (not clothing) combined, and skin that normally.  Then, I'd take the separated parts, and copy skin weights to them from the master mesh.  That way, the separated parts should all get the correct matching weights at the boundary.  If I need to make further changes to the skinning I can just edit the master and re-copy weights, without needing to try to carefully match the separated meshes.

Note that you might also need to watch out for normals at the edges.  Normals might not flow properly across the boundary like they would with a single mesh, which can cause lighting seams.  You could probably work around that in a similar way (copy normals from the master mesh), but I haven't done that.  Displacement maps might also run into issues.  It would also cause issues with mesh smoothing, but that's probably not an issue for games.