Clavical IK flip issue

[inspleak]

Hey guys... quick question...
I currently have a rig for the clavicals of my character (normal bi-ped) where there is a joint parented to the spine (clavBase) and a shoulder joint that is parented to the claveBase joint... then the rest of the arm hangs off of the shoulder joint...

for the rig I have an IK handle that goes from the clavBase to the shoulder joint.... with this I can lift and move the shoulder...

to make it easier to grab I have the IK handle point constrained to a poly cube... the problem happens when I turn the character 180degs... the clavical IK flips upside down... To fix this I have to adjust the "twist" attribute to rotate the IK back to where it should be...

anyone know why this happens and how I can prevent it?

thanks ever so much!

-Jake

[joojaa]

you should use pole vector constraints and animate them! but yeah what happns is you go over the pole and the exact opposite is iterpreted!

[inspleak]

sweet... that sounds about right... I wasn't sure if that mattered when it was a 2 joint system... (no joint in the middle)

thanks again!

-Jake

[joojaa]

Well theres allways 2 joints in maya. Bacause tha balls represent joints so theres always a joint in both ends of a bone!

[gnimmel]

If you only use a point constraint then the IK handle will never rotate with the character. I'm guessing you where using a single chain IK handle? if so all you need to do is orient constrain it as well. Even better might be to simply parent it. If you use a RP IK handle then you will probably need a pole vector as mentioned, but if you use a SC then you shouldn't need a pole vector which might get in the way, just remember to parent or orient constrain as well.

Richard