During my undergrad I wrote some simulations of ballistic deposition that produced patterns that looked very similar to this. edit: Here's a video someone else

During my undergrad I wrote some simulations of ballistic deposition that produced patterns that looked very similar to this. edit: Here's a video someone else created of a similar looking situation http://www.youtube.com/watch?v=j-1uotbxrcc http://www.youtube.com/watch?v=j-1uotbxrcc