IK arm problem.....

[5TEF]

this is my IK setup for my arm....

[Remi]

Give it elbow goal too or just blend Ik with Fk....you've got the right idea....:thumbsup:

[DaveW]

You should try not putting any limits on the joint. Instead, when you apply the ik, make sure the arm is already bent in its rest position. This solves problems like the joints snapping or bending the wrong way. If you really want to put limits on the joint, make the elbow bend backwards about 10 or 15 degrees more than you actually want it to bend so that the arm can ease into it's straightened position.

[webfox]

Try a rotation limit on how far the elbow can bend. Also, maybe set "keep goal within reach." Be sure that when you build your setup that the elbow is not completely straight when you create it... bend it a tad. Then, set your limits so that it never opens completely up.

Also, it looks like you're moving your null in too much of a straight line and too closely to the joint that the IK is affecting. That's why you get the pop as well as the fact that the joint is allowed to bend too far.

In the attached image I made, you can see how, even though A and C are much further distances traveled by the null, that little distance of B gives you a lot more angle change in the joint. So, if you keep your null further out, the elbow's angular motion will be smoother.

Hope this helps.

[SplineGod]

Heres a couple of tips:
Dont extend IK past the arm. It just becomes a real pain to get things to pose correctly, which is the goal of using IK. I keep my IK chains as short and simple as possible. I adjust the collar bones via FK.
The 2nd thing is that you should move your IK goals in arcs.
Strange things can occur when you stress your IK solvers by moving goals in linear paths. Things move in arcs and so should your IK goals.

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