Hi, I am trying to use the quaternion class for 3d rotation and wonder if anyone has a sample of how to do this. If we have quaterion q1 and want to rotate by q2 the expression, I believe, is result = q2 * q1 * inv( q2 ). Is the correct syntax using ::boost::quaternion operators result = q2 *= q1 /= q2 ?? Do the quats need to be "unit quaternions" before these operations? What is the best way to create an unit quat? thanks john ware