position constraint

I have a simple character rig and i applied posisition contraint on some bones (head, upper torso) so as the previous bone dont affect rotation .
However i intend to make a flip in the air animation but when the bones(with constraint) are rotated more than 180 deg the bones flip(jitter) .
I have given pose space on both taget and owner in contraint field but nothing changed.
Any workaround on this issue ?
If you want jpg with the frames showing the problem let me know.

I uploaded a simple scene to show the rotation issue i m having.
Thanks in advance.


rotationwith position contraint.blend (160 KB)

Instead of using the location constraint to do this, I would recommend enabling “hinge” on the bone instead. Hinge prevents a bone in a hierarchy from inheriting the rotations of its parent, creating the same effect you have here.

I would also strongly recommend you use a bone for you IK pole target instead of the empty. It is a good idea to keep your controls in a single armature for ease of animation.

As for the rotation issue, it’s just a matter of understanding how Quaternion rotations work. In 2.5 I understand armatures will support Euler rotations, but for now all bone rotations are Quaternion. There are great explanations and example files showing how they work in this thread.

thank you , hinge works perfect.
I will definitely have a good look at your rigging tutorials.
Although the quarternion problem remains.Any ideas how the character do the flip animation?
Much appreciated

Just to be clear, not all the tutorials in my signature were created by me - it’s a collection :slight_smile:

Vertex Pusher provided a demo file of spinning an object infinitely using quaternions in the thread I linked to above. Cessen also provided great explanations and ‘hands on’ demo files to play with. I know the thread is somewhat long, but it really is worth taking the time to read it and study the examples. It taught me enough to be able to do this animation, which has a lot of ‘flips’ and ‘spins’ :slight_smile:

sorry about my late reply, thanks for the links you provided .
Adding keyframes every 90 degrees seems to be the way to go.
Thanks again