My first attempt with Processing. I only downloaded the IDE yesterday afternoon, and spent about 3-4 hours playing around with it. For a first project, I built a 3D clock where the circles of tetrahedrons represent hours, minutes, and seconds. Each circle is rotated on the axis of its clock hand. Press and drag mouse to rotate the clock. Hold down any key to flatten the clock (holding down the key may also sometimes crash the applet).
As usual, I tried to come up with some re-usable code. You might find the Point, Polygon, and Solid classes handy. Some of the code could probably use some simplification, suggestions or tips on how to improve my techniques are welcome! This is only the second time in my life that I've written code for 3D (the first time porting some C code from Andre LaMothe's book into Flash 5 Actionscript). Hope to work on more meaningful experiments soon.