A quick little motion test of the rig in action:
Umbrella Rig Demo 1 from Joshua Leung on Vimeo.
Actually, it's been working since Sunday, though I've been trying to tweak it still, since the closed state is still a bit problematic.
In particular, it actually has some rather nasty intersection problems when you close it up a bit more than shown in the video, which I'm currently still trying to find a solution for. Then again, it's not bad considering that this is all just automatic weighting for the canopy (and hand-weighted for the rigid parts).
Perhaps I could try adding some extra controls to control how those problem areas fold. Or perhaps I could try some cloth sims there (I'm not terribly optimistic about using this though, especially after seeing the problems it had in the wing tests for Durian, and also considering the runtime problems with sims).
Anyways, here's the current state of the rig: