Hi Everyone,
I have a character who needs to walk on his hands but also needs to be
able to gesture w/ them. I did apply the FK/IK solution to the arm as
Chris Landreth described at his Maya Master Class in Siggraph 99, but
his example didn't extend to the hand so there's no IK control of the
fingers. Therefore, when I move the character forward the hand pivots
at the wrist because that's where the IK holds it in place. This would
require a lot of counter animation of the hand and would probably end up
looking clumsy. I THINK the answer to my problem is some version of this
FK/IK setup, but I'm having trouble applying it to the hand.
When the hands are on the ground they should work the way a foot does, w/
a palm/heel strike, ball roll and finger/toe off. But adding IK handles
to the fingers (or constraining them as you would in a reverse foot setup)
really limits what I can do w/ the hand for gesturing by controlling the
fingers w/ custom attributes like Grab, Fist, or IndexCurl, because these
essentially work w/ FK (right?).
Maybe you (dear reader) could comment on a couple solutions that may or
may not work:
I could switch between constraints on locators, but it would be ideal
to have one set of locators for the ground that are independent of the rig
and another that are children (or at least follow) the joints themselves
so that I can use FK on them. Otherwise I'll be animating a lot of
separate locators to get hand gestures.
Would it be possible to have two skeletons for the hand? Unlike the
FK/IK solution, I thought about having two separate but identical models
of the hand, each w/ its own skeleton, and I could switch their visibility
as need be. But this might be more troubel than it's worth, trying to
match their positions when transitioning from one to the other. I would
also have problems working w/ surfaces (the arm and the hand) that are not
continuous.
I realize there's never one perfect rig for all of a character's possible
motions so I'm really just looking for the best compromise. And I should
mention that this all takes place in one shot, so I can't have two or more
different rigs.
At this point I think I'm just going to set up a reverse hand w/ the
fingers in a neutral position and hope noone notices that it's sort of
stiff when the character gestures with it. I'd be happy to send the
current character rig if it would help make my situation more clear.
Thanks,
greg