title: Rotating a light cone to a given axis
body: <p>Suppose I have a cone of evenly distributed points starting at (0,0,0) and with its main axes along (0,0,1). I need to create a python script that rotates all points, so the cone is parallel to (1,1,1). What is the easiest way to to this using spherical coordinates?</p>
  <p>For now, I've been transforming my spherical coordinates to cartesian ones, applying Rodrigue's formula and finally transforming the coordinates back again to spherical. But there should be an easier way, right?</p>