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Broken facial joints and shearing from spine stretch


Hello, when I enable spine stretching I find my lip and eye joints move incorrectly. This happens with both spine_ik_01 and spine_ik_02.

When I looked into it a bit I noticed that spine stretching causes shear transformations down the joint chain. I’m not sure whether this is intended or whether it is the cause of the problems.

Edit: noticed this happens with neck IK stretching as well.


Did you fix the lip rope scaling as indicated in these threads? This might solve the problem, or at least part of it.


Thank you for the pointers. I saw variations on this were a fairly common thread topic and found a thread on spine and neck stretch here where Miquel recommended “Force uniform scaling on all joints.” Enabling that option fixed the problem so I didn’t attempt any more manual tweaks.

(I’m just using the basic lips rig, rope doesn’t play very nicely…)