Return current position of camera based on center, dist, elevation, and azimuth
Orbits the camera around the center position. azim and elev are given in degrees.
Moves the center (look-at) position while holding the camera in place.
If relative=True, then the coordinates are interpreted such that x if in the global xy plane and points to the right side of the view, y is in the global xy plane and orthogonal to x, and z points in the global z direction. Distances are scaled roughly such that a value of 1.0 moves by one pixel on screen.
Return the approximate size of a screen pixel at the location pos Pos may be a Vector or an (N,3) array of locations