I had this idea once to do a short animation set under water. This test was done to see if I could create a nice looking underwater environment. My underpowered computer at the time, and the technical complexity of 3D water effects were the main reasons for putting the project on hold indefinitely. This test alone took way too long to render, so I had to abandon this idea. At least it made for a nice screensaver.
Tags: animations, lighting, tests, underwater