I (mis)used perl for 3d graphics last time. You can get the source code from http://www.math.bme.hu/~ambrus/pu/tri. You may not understand it as it lacks comments. I do not develop this program any further. It outputs a ppm.

Note: this was for university class too.

Update. Let me complete the story. I wrote the thingy in Perl because I did not have Mathematica at home. Later, I converted the program to Mathematica in the university, so what I've really given as a homework was a Mathematica program and an article explaining it. (In my case, however, it was obligatory to use Mathematica.)