Okay, I think that I’ve found the problem: the scabbard is being culled on-and-off, presumably as the character and camera move relative to each other.
Calling “Actor.fixBounds()” seems to solve the problem, but with one issue: according to the documentation, it won’t work unless a few frames have already been rendered. Simply having it be called on every update seems to work, but is there some way of telling when the Actor is “ready” for “fixBounds” to be called, so that I can perhaps call it just once?
[edit] I tried giving the Actor an “OmniBoundingVolume”, but oddly, that doesn’t seem to help. o_0