Note: This is implemented in Processing 1.5. It won't work properly on Processing 2.0. At some point I will get around to fixing this but for now use the old one to get it working.
To run the code, you need Processing with the following libraries installed:
Press the spacebar twice to toggle between first person and third person viewing mode. While in first person mode only (the default), you can fly the camera around the scene by click-dragging the mouse, and zoom with two finger-scroll (mac) or the equivalent. While in third person mode, pressing different numbered keys will trigger third-person presets moving the camera around the scene in various ways.