IK chain not orientating to pole vector in Maya

Rigging
1

Hi all,

I’m getting this weird problem in Maya with my FK/Ik arm rig where the chain’s elbow does not seem to point at the pole vector constraint. The control object for the PV does control the chain, just in quite an odd fashion, which the gif below should indicate. It gets to a certain point and then the elbow rapidly points a different direction.

See .gif here

It’s a pretty straight forward setup - FK chain, IK chain and driven chain which is part of the main skeleton. But the problem itself occurs in isolation too.

I’ve never seen this before, and I have identically set up rigs, albeit on differently proportioned characters, which work with no problems.

Just wondered if anyone had any ideas what I was doing wrong, things to check etc. Just to clarify, it’s not the IK flipping, it’s sort of wobbling.

Thanks in advance. :slight_smile:

2

This happens when the joints are not perfectly aligned to the rotation plane. The best way to ensure they are is to draw the joint chain in an orthographic view, then rotate them into place. If you have to translate child joint only use local axis mode and translate only along the aim axis of the joint (by default this is the X axis).

If you can’t draw the joints in an orthographic view, then use a good Orient Joints tool to orient them properly before creating the IK solver.

3

Thansk Stev, I’ll take a look at that :slight_smile: