Arm flips 180 degrees from desired location

How would I fix this?

Ok, it looks like I had to add some rotation to one set of bones, and lower it on another.

edit, but how can I make a axis preferred?

Like I want shoulder X to be rotated, not Y as much? stiffness?

Almost looks like a cyclic dependency problem, but it probably isn’t. To check for this. tab into & out of edit mode and check console for error messages.

Does the ik arms have pole targets? If not, then you should probably add them.

But what I really think is going on here is the bones in rest position don’t have any (or enough) pre-bend to them. This, with the lack of pole targets, could be the problem.

Hard to say without seeing the file… Just guessing…

Like I want shoulder X to be rotated, not Y as much? stiffness?

Normally, yes, you want to adjust the stiffness, but I’ve sometimes had mixed results with this. Generally, I just have an arm’s ik control the lower and upper arms, not the shoulder. The shoulder I animate separately. Then the pole target controls how the upper and lower arm bones look. For example: a character sitting at a desk with it’s hands on the desk. If the character is resting, the elbows would be in close to the body, if the character is trying to stand up, then the elbows would be out away from the body as the character stands up. The changes between these two poses would be accomplished by moving the pole targets.

Anyway, if this doesn’t help, post up a .blend file…

Randy

I got it, I had to rotate the bone myself slightly in pose and it “snapped” the way it needs to be,

also, this is for a game, and it will use always run armature. I am not sure if pole targets add any overhead or not ?

Another strange thing,

65+ms for animation solving with standard in blender 2.72,

switch from animation -> itasc -> 3 ms

???

it was never this drastic before…