Mesh twisting when animating with IK

[brandon-lemon]

I don't know why I have this mesh twisting problem when I animate with IK. I have an IK/FK toggle attribute but I don't think that would be causing the problem. I'm not sure if I have to set rotation limits or what, I remember someone telling me not to use rotation limit with IK but I'm not sure now. Can anyone help?
Here is an image of the twisting problem.

[norbert-nacu]

Hello There,
    Did you check your poleVector constraints?  Is it possible to send us the file?

Thanks,
Norbert Nacu

[brandon-lemon]

Well, I just went into the poleVector constraints, but I really don't know what I'm looking for there. If sending you the file is the simplest way, I'm more than willing to do that. Just let me know how to send it.
I appreciate the help I get from this website.

Thanks,
Brandon.

[benjamin-graham]

Hey dude.
 Hard to say exactly what you need to do but this is a very common problem. Basically you should have an extra joint in the foream between your elbow and your wrist then you set up either a driven key or an expression (driven keys being faster than expressions and more intuitive to setup) on that mid joint that drives its rotation so that it assumes half the rotation of the wrist joint. Thus when you have nicely painted weights it spreads the rotation across a longer distance and prevents crumpling of the wrist joint. But this is fairly common and you may well already have done it but it's the most obvious solution. Of course then you have to get the ik effector in the right place and honestly I haven't done character setup in a while and can't remember it offhand. If you're really keen to know this I'm sure there's a tut somewhere on it as it's not hugely complex. Ultimately the wrist is going to crumple if you push it too far. Setting up limits will only help because you won't be able to push the wrist too far but setting limits will not solve the actual problem far as I can tell.
Hope this helps and I haven't misinterpreted your problem.
Benjamin.

[brandon-lemon]

Thanks for the reply. I do have a forearm joint mid-way up the forearm that is taking part of the rotation. However, the problem occurs not when I rotate wrist but when I animate the arm in general (I'm using IK). I know some basics of rigging but this is more troublesome than I'm used to. There are ways around this deformation (for the most part) if I keep the arm for performing any "extensive" motions I can keep it out this "deformation zone". I was able to get a pretty decent walk cycle out of it, but when I went for a simple arm swiping/slashing motion, it went crazy.
I thought it might be the rotation limits but when I would select the joint, (with the deformation in place) it wouldn't un-deform, just deform more.

Thanks again,
Brandon.

[joojaa]

Use quat interpolation.