The following links to a discussion that includes a download link to Bantam3D, one of those little gems that you may find useful.

Bantam3D was available as freeware for a time but the source Site disappeared and it has been hard to find.

A nifty 'ground-cover' generator, it makes great grass (.obj format export).

http://groups.google.com/group/Ruby-API/browse_thread/thread/671b5c299e51c7ce

Scroll to the bottom of the screen... "dmatho"

Enjoy