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View Full Version : Targeting before IK?


Dennik
10-25-2004, 02:46 PM
A quickie question. Is there a way to target an object to another, before IK calculations? Through an expression that is. I couldn't find an expression doing this.

Carm3D
10-25-2004, 10:07 PM
I thought targeting was done before IK. How about you tell us what it is you are trying to accomplish. Even upload a rig-xample if possible. Cheers.

Dennik
10-25-2004, 11:32 PM
Well i found the other day, that if i setup an arm ik chain that is parented to a bone, which is targeting directly the ik handle, then automatically i get a very stable ik that can spin around in all directions. The problem is that both IK and targeting don't work well together.

The only way i found to overcome this problem, is to put a motion baker on the targeting bone, but then it acts funny when you scubb back and forth, untill it bakes all keyframes, and it doesn't preview at all (motion baker bug?)
Anyway any suggestions are appreciated. :)

Carm3D
10-25-2004, 11:51 PM
It sounds like pre-baking the targeting bone will be your best option. But you must un-target your bone after you bake it's targeting rotations. -then the IK will work fine.

kretin
10-26-2004, 01:46 AM
Since there is only one behavior for targetting, it's good that it's after IK so you can target items within an IK solution... it would be great to have the option to target before IK though.

For what you're doing, instead of targeting the parent bone, try adding it to the IK solution, enabling IK then setting the IK Goal of the child (the first IK bone in your original setup) to your main IK Goal. That should be more stable and provide the results you're after.

Sounds like a strange setup though, the IK for an arm doesn't need to be complex to be stable. I think there's prolly an easier solution...

SplineGod
10-26-2004, 08:23 AM
You would definately not want to mix targetting with IK in the same chain. It will appear to behave while youre using it but screws up after. The same thing can happen with expressions or motion modifiers. The best thing is to keep it as simple as you can. :)

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