def evaluate(self):
"""invokes the constraint causing the output value to be computed.
Return:
Boolean, True if successful.
"""
if self.getMaintainOffset() is False:
newOri = Quat();
newOri.set(Vec3(), 0.0)
for constrainer in self.getConstrainers():
newOri = newOri.add(constrainer.xfo.ori)
newOri.setUnit()
self.getConstrainee().xfo.ori = newOri
return True
