Yeah that's what I'm really interested in. I get how the shader rendering works for amazingly complicated geometry when it's just a simple function to calculate it, like a fractal or something like that, but when you have a world full of irregular, non-repeating shapes how do you represent that?
Each cell can contain any number of arbitrary shapes (and they can intersect, despite what my test environment might suggest). Even the most irregular shapes can often be approximated mathematically, in ways that you might not be as complex as it seems. I would read up here, there is a wealth of information on these topics (and lots more if you google around):
http://www.iquilezles.org/www/index.htm
