View Full Version : Ik pole vector problems

01 January 2006, 10:22 PM
I have an entier skeleton set up and I'm moving onto adding the IKs but everytime i drop an Ik on an Leg or arm (Toe fingers ect) I get really funky pole vectors that are pointing in the wrong direction.

I know that usualy they are supossed to go down the third rotation axsis (Z in my case) but they are usualy pointing off to the side on the Y axsis and no matter how much i fiddle with the Orentations of the joints they refuse to go into the rite place. kind of like a gimbal lock.

on majior Ik's like the legs and Arms I can almost fix the problem with Prefered angle but when they have odd pole Vectors it sometimes moves the children joints by forcing down rotations as i apply the Iks.

its the most noticable on single joint to joint IK chains for the Foot Set Driven Key set-up. since the prefered angle means little to nothing on a 2 point Ik chain it messes up all the time

since working with prefered angles and orentations fails to produce results I was wondering if there was a way to change the direction of the Pole Vector without adding non 0 value (such as compensating with twist)

in joints there is a sub-component to alter the orentation, is there a way to alter the local Pole Vector Axsis in much the same way?

01 January 2006, 12:29 AM

you have to make sure that the object you are using as a polevector constraint is in the solve plane for the IK BEFORE you hit constrain. a way to do this is to point constrain it to shoulder+elbow+wrist, no offset then aim constrain to the elbow on default settings NO OFFSET then translate in X which should move it back still in the solver plane. then delete those constraints on the object and make it the pole vector constraint of the IK. this really works. if you do it right there will be absolute no jumping when you make it the PV constraint.

good luck.


01 January 2006, 01:52 AM
well I can add Pole Vectors and I know that process works but the issue I'm running into happens at the creation of IKs.

I first noticed the problem when I was adding a Pole Vector constrant as well. the object was well outside the apropreate range of a good pole vector (almost beside the object) but the IK bent the arm in the wrong direction even with correct Orentations and prefered angle.

the point I'm making with my question is that my pole vectors seem to collect wrong information on the vector plane or something and make it impossible to work with the rig.

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01 January 2006, 01:52 AM
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