CGTalk - IK/FK arm trouble and critique

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diegosocart12

02-22-2006, 07:06 AM

I have built a skeleton with an arm that actually has an IK and FK arm that orient constrain to a Bound arm. I have an IKFK switch for them. I have followed a tutorial for this creation. My first question, because it is unclear to me, in a setup like this, should the Bound arm deviate from the position of the IK arm position? I have included a screen grab for reference. The top arm is the Bound arm and the one below is the IK arm. The shoulder is the far left joint, and the wrist is the far right. I have a second question which is, in a good IKFK setup should the animator be able to move the the Bound arm under IK constrain, then switch the Bound arm to FK constrain and move the Bound arm from where it was last placed in IK constrain without any pop to the position of the FK arm? I hope that someone can help.
-Thanks

Goon

02-22-2006, 10:49 PM

wrong place to post. should be in Maya>Character Setup forum

there should not be any deviation between the positioning of the deformation chain and the ik chain, unless it is partially blended with the fk chain.
the basic setup is a simple blend between the two controlling fk and ik chains, the deformation chain is there for deformation only, and should not be directly animatable. a blend switches between the two.

a better setup is using this three chain setup and having a method of snapping the fk->ik and ik->fk so that there is no popping, and no blending across frames, which can introduce some funkyness.

a different setup is to have it layered:
ik chain and ik handle, with pole vector, controlled by fk controls, controlling deformation chain
so that you can animate in fk, then use ik, either for additional secondary movement layered on top of the fk, or in its standard ik role, while the fk chain is still.
a script is used to pop the ik controllers back to 0,0,0 while adjusting the fk controllers to match the ik chain's orientation.

diegosocart12

02-23-2006, 11:38 PM

Thanks for your help. I'll give that process a try and post this in the character setup forum like you said.

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02-23-2006, 11:38 PM

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