0
$\begingroup$

enter image description here

How can I make bone 1 copy half of bone 2's Y rotation? I've tried using a copy rotation constraint with a .5 influence, but due to the limitations of Euler rotation, it is causing unwanted X & Y rotation (bone 1 is dampen tracked to bone 2, which is parented to a non-deforming hidden bone connecting the bones on the far left and right)

$\endgroup$

1 Answer 1

0
$\begingroup$

Euler angles are not 3 independent rotations; they are three ordered rotations. To rotate a bone in its local Y axis without affecting the location of its tail, it's necessary to use a YXZ or YZX Euler order for reading and writing that rotation:

enter image description here

The selected bone here is copying the local->local Y rotation, with an influence of 0.5, from a bone sharing the same parent.

Copying to or from rotation in a different space would be a problem, because the Y axis of that other space may not align with the bones' axes.

Because of potential issues with spaces (and with Euler aliasing), I am more likely to locked track a marker bone than I am to use a copy rotation constraint:

enter image description here

I've created a marker bone, parented to the original target of the copy rotation, and then I'm rotating our constrained bone, along its transformed Y axis, half of the way to point its +Z axis at that marker. Doing so doesn't depend in any way on the space of either bone. I recommend thinking about bones not in terms of their Euler angles but in terms of which way their axes point-- the finer details of Euler angles can be unintuitive.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .