[tarr11]

There is a cool algorithm called space colonization that can do a lot of what l-systems do (such as tree modeling). Pretty straightforward to implement and has some nice results.

http://algorithmicbotany.org/papers/colonization.egwnp2007.l...

[abelaer]

For the curious: I've written a basic space colonisation algorithm to simulate leaf venation patterns in a browser here: https://openprocessing.org/sketch/1211361

(note: I wrote this many years ago and it's horribly inefficient, I don't even dare to look at the code anymore, but it's on that same page)