Constraint World/Local/Pose Space

Hi I am back into Blender after a few year hiatus. I can’t seem to remember how to apply a copy rotation constraint, with an offset, and maintain the proper rotation and axes.
I read the Wiki pages but I don’t really understand, and I can’t seem to get satisfactory results unless my constrained and target axes are aligned the same before the constraint is applied. I am wanting to copy a rotation from one joint, apply to another joint, but maintain the offset. Does this explanation make sense?
When I use the copy rotate constraint, the constrained object jumps to match rotation of the target, and no matter what combination of world/local/pose I use sets it back.


do you use bones or object?

Personally, for offsets like this on bones and objects that should copy rotations of others, I always use Drivers for the rotations, so the first control bone is key-framed as normal, then the other uses a scripted expression driver like var + (pi /2) where var is the rotation of the first bone and (pi /2) for example is 90 degrees (this bone copies the rotation of the first but is 90 degrees ahead of it), remember all driver rotations are in radians and there are 2 * pi radians in 360 degrees. This works every time, don’t forget to check “Auto-run Python Scripts” in User Prefs > File Tab.

Cheers, Clock.

I am trying to copy rotation from an object to a joint. An ik
controller made from a mesh, to a bone in the hand.

Sounds like the alternative I may be looking for. Thanks!

Drivers are a good solution when you connect object to bones or bones to object.

Only bones have world/local/pose and so it could be tricky to connect them to objects, usually I would use bones to do the inbetween and add a child constraint on the object to this bone.

Why are you using a mesh object for an IK target? If you want a custom shape for a bone to use as a controller, set the bone shape in the bone properties.

Below I have a cube called custom shape and a bone called bone set to use that shape. To place the custom shape in the correct position, edit the mesh and move the vertices to their proper orientation/scale/etc.

Any mesh can be assigned as a bone shape. Often it’s helpful to click the wireframe checkbox for your custom mesh/shape.

Good luck!

I apologize profusely. The ik target is a bone with a shape display. D’oh!
Been a while ;). I’ll get back in the swing of things before too long.