Now I have quaternion data representing the orientation of wearable devices. Because people wear it differently, the initial quaternion is different for each person. I want to align their movement data based on their initial quaternions.
For participants 1 and 2, their initial orientations are p1 and p2, their movement quaternions are q1 and q2. I want to align q2 to q1, so I tried:
r = p1 * p2', where p2' is the conjugate of P2
q1 = r * q2
based on another post, but it doesn't work.