If any of the rigs or animated meshes in the same file are disabled (or deleted) in Unity (when a file contains more than one), the model distorts in unintended ways.
In my case, it seems to distort towards my character, and seems to mimic the animation (if I walk, the model starts moving, it stops when I stop, etc.). (One of the animated objects is a character, and uses the same bone structure as my character, however I don’t know if this is relevant. This object is not animated yet, and the rig does not affect the other object.)
This occurs when:
I disable or delete any object(s), if these objects are rigged
I disable or delete any rig(s), if they affect any objects
When I use the -force-opengl argument to launch the game, this does not happen.
I can’t seem to reproduce it in a new project, and I can’t make it happen again in my main project either. I don’t know what caused this, but it seems to be working fine now. I’ll post here if I find out more about this.
Interesting… Apparently setting the “Quality” of the skinned mesh renderer component to “2 Bones” makes the model render normally (both in the editor and in build). Setting it to “Auto”, “1 Bone” or “4 Bones” instantly causes it to distort again.