plant

Click Tree v1.0.ms

The idea behind Click Tree was to write a
script that allows the user to plant simple
massing type model trees, of various type
and size, on a surface simply by clicking.

A billboard manager!
by billboard I mean a 2dface with an opacity map from an alpha channel.
Quickly create 2d faces from bitmaps, make them follow camera, change their opacity and visual appearance, etc...

with tree shop you can easily plant trees (plane mashes with opacity-mapped bitmaps) into your scene.
each tree is an 'intelligent' object which allows later interaction - like changing/randomizing size - aligning it to the ground (gravity) - changing orientation and map (tree type).