As part of my course on computer graphics this semester the class has been writing a ray tracer. The details of ray tracing aren't really worth going into, instead I'd rather share a picture (more technically a rendering) that is the result of my work.
If you are particularly learned, you'll recognize this figure as the Mandelbrot set. In case you didn't recognize it, at least you will in the future! This version in particular is really an abuse of the ray tracing engine we've developed; typically other much more efficient means are used to generate an image. However in using the ray tracer I'm able to generate images that simply couldn't be done with the more traditional methods. For instance, this rendering uses a reflection model to add an additional layer of the delicious recursiveness that characterizes fractals. Though you could do the same given the more traditional code, simply having the code alone versus a ready-made rendering program allows me to color the actual Mandelbrot set, which is almost always left black:
For the sake of completeness, here's a more traditional ray traced image that specifically includes a good variety of capabilities a ray tracing engine made in a single undergraduate semester has:
As you can tell, my cylinder code still has some issues that need to be resolved.