A Few examples of the applet.
Below is an example of pure reflection, with realtime ray tracing turned
off. There is only one slab, and only the bottom floor is reflective
(the rest are absorbent).
Below is an more advanced example. We have included both Slabs, 1 refractive
and 1 reflective. Now the floor and right walls are reflective. Also
the ray tracing is done real time.