I try to write a constraint which limits orientation of a body. (spherical joint)
For example, i want to limit orientation from (-30, -30, 0) to (+30,+30, 0).
I have tried to use two hinge joints (X axis and Y axis) but the
result seems unstable.
I have tried to compute axis angle from orientation matrix, in order
to deduce torque to apply. The results seems unstable too.