I could be mistaking the cause, but there doesn’t seem to be a way to define an up vector for the multi aim constraint, meaning this system is unusable to control a head’s turning as it creates some really unnatural positions.
Is there a workaround to this?
Correct, the multi-aim constraint does not have an up vector. We are aware of the issue and its implications. We hope to address this soon. It may be a while before this makes it way to the public package however…
A work around could be to duplicate and modify the multi-aim constraint to take an up vector into account. The algorithm for the multi-aim constraint can be found in Runtime/AnimationJobs/MultiAimConstraintJob.cs. Alternatively, locking axes on the constraint might just work out depending on your case.