quaternion_multiply

compas.geometry.quaternion_multiply(r, q)

Multiplies two quaternions.

Parameters

• r (list) – Quaternion as a list of four real values [rw, rx, ry, rz].

• q (list) – Quaternion as a list of four real values [qw, qx, qy, qz].

Returns

list – Quaternion \(p = rq\) as a list of four real values [pw, px, py, pz].

Notes

Multiplication of two quaternions \(p = rq\) can be interpreted as applying rotation \(r\) to an orientation \(q\), provided that both \(r\) and \(q\) are unit-length. The result is also unit-length. Multiplication of quaternions is not commutative!

References