LC #42 Pipers Alley

View Full Version : Forearm twist on IK arm?

06-29-2011, 05:51 PM
What I have at the moment is an IKFK arm setup, and I have the twist on the FK chain, but on the IK chain, when I move the arm control the forearm twist snaps back to its original orientation. Is this normal for the setup? Or am I doing something wrong? Thanks for any help.

06-29-2011, 05:54 PM
I forgot to mention, there are 4 joints down the chain shoulder, elbow, forearm, wrist. Working in Maya 2011 as well if that makes a difference.

06-30-2011, 01:43 AM
Have the twist joint independent of the FK/Ik jnt. Feed in the FK or IK (anyone) shld jnt value through a blender(utility node) to the Twist jnt. Also u can distribute the twist down the twist chain depending on the no. of twist jnt through Multiply divide (utility node) and divding with the no. of twist jnt.

07-05-2011, 05:18 AM
Ok, the thing is if you are going to connect the rotation to the twist joint, you are gonna encounter flipping as a result of so called GIMBAL LOCK! I suggest you to use the power of aim constraint with up vector. Or, you could create a joint chain; setup a spline IK and use advance twist controlled via object Up (Start End).

Cactus Dan
07-10-2011, 04:14 PM

I agree with Boucha. I always use aim/up vector constraints for forearm twist. ;)

Cactus Dan

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07-10-2011, 04:15 PM
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