I need more study and information.
[rx, ry, rz] is "arbitrary rotation axis," not a rotation matrix, but [Rx] [Ry] and [Rz] can be individual 3x3 rotation matrices.
So the camera rotates left to right, and tilts up and down, and could also roll, and also Translate in 3d space.
The laser is rigidly mounted to the camera at some distance D from the camera?
The target sits at say the origin.

This link has pitch and roll trig:
https://pdfs.semanticscholar.org/3046/e4b57081ce9fd51b6a96012219f454ac3e88.pdf

- Brian