not exactly in your saber action
vec_for_vertex gives a Location vector not a direction or angle vector

you subtract the FROM vector to the TO vector to get a direction vector from FROM to TO

then to convert a direction vector to pan/tilt/roll angles is done with vec_to_angle

and then if your using a sprite you will need (if i rexcall right) to add( or subtract) an 90 degree offset to the pan angle.