Applying Rotation Quaternions to Vector3D or a new Rotation3D concept?

[yilangmok]

I'm trying to applying a rotation quaternion to a Vector3D and I'm not seeing any support in the library. I don't see any functions (or operators) that interact with vectors and quaternions. I ended up writting my own extension functions to apply the rotation quaternion qpq*.

Is there an opportunity to add these quaternion/vector interactions to the library, or is there a reason not to (e.g. because quaternions go beyond just rotations)?

Alternatively, would it be better to introduce a Rotation3D class that can be initialized by a quaternion, axis/angle, euler angles, or a matrix, and also return the other forms?