Before we dive into the density package to view some volumetric data, take a quick look at the flight path capability of the density viewer. As you maneuver through the seen, you can add way points for the camera. These are marked with draggers that allow you to modify the location and look direction for each waypoint. One you have a waypoint file that you like, render the frames to disk, drop them in a program like Quicktime Pro to make a movie.