View Full Version : Locking position of knee or elbow

04 April 2007, 07:02 PM
I'm trying to set up a rig that allows me to plant/lock/pin a character's elbows or knees to the ground (or any other object), so I can animate things like genuflecting, crawling, knee-walking, yoga exercises, aikido take-downs, etc without pulling out all of my hair.

I've been bashing my head against this problem for awhile. So far, I've come up empty-handed. Does anyone here have a solution they could share?

I'm familiar with both Max and Maya, so any flavor solution is good. :)

04 April 2007, 11:47 AM
for the elbow is quite ik from clavicle root to elbow and the forearm in fk
for the knees....i don't know, i'll think about it ;)

04 April 2007, 07:41 PM
Ah! I knew it had to be something simple! :) Thanks! I have the elbows working properly.

I'm now fiddling with the knees. I have a spline circle (named "ctl_hips") set up as the root node for the skeleton, two fixed hip bones ("bn_R_hip" and "bn_L_hip"), then the thigh and shin bones. Setting up an IK chain from a hip bone to a knee bone doesn't do the trick, but setting up an IK chain from ctl_hips to a knee bone works well. Unfortunately, when I set up another IK chain from ctl_hips to the other knee bone, that knee wanders all over the place. I might have made some sloppy mistake in setting up the skeleton, so I'm going to go back and make sure everything's neat and tidy.

04 April 2007, 03:24 PM
it might have issues....but i think it should work

04 April 2007, 05:34 PM
the setup i posted earlier was done in about 15 minutes in my lunch break....
after testing it i realized it does have some issues (i.e. you cannot control the hip rotation....).. the calf was rigged just to stay locked...whatever ... it's not important in our case

but that's the basic ideea

the coolest thing would be to switch between knees lock and foot lock (i mean a comoon leg setup - i use triple ik leg). i'll think about a method someday (but unfortunately i have less spare time lately and i preffer having some beers ;) cheers!! :thumbsup: )

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04 April 2007, 05:34 PM
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