quaternion_multiply

compas.geometry.quaternion_multiply(r, q)[source]

Multiplies two quaternions.

Parameters

• r ([float, float, float, float] | compas.geometry.Quaternion) – Quaternion or sequence of four floats [w, x, y, z].

• q ([float, float, float, float] | compas.geometry.Quaternion) – Quaternion or sequence of four floats [w, x, y, z].

Returns

[float, float, float, float] – 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

• Quaternion: http://mathworld.wolfram.com/Quaternion.html