Version: 2.73 (Linux 64-bit)
How to reproduce:
- Open the attached .blend file and inspect the bone chain.
- Notice that the root bone is rotated 45 degrees, and that the distal bone inherits its rotation from a Child Of constraint.
- Try rotating the distal bone on one local axis, either by pressing R, [XX, YY, ZZ] or by using the rotator widget in gimbal or normal mode.
- Notice that the bone does not rotate on one axis as one would expect it to. Sliding the numeric rotation values still works.
It is useful in rigging to use a Child Of constraint to make a bone inherit its rotation from a bone other than its immediate parent (often one further up the bone chain). However It appears that the Gimbal/Normal transform does not take into account the visual transform created by the Child Of constraint. Weirdly, turning on the Location axes for the Child Of constraint seems to solve this problem, however this makes no sense and can cause separate issues for unconnected bones.
How can this be solved?