This was my first fully working tree model for Torque 3D, build all by hand in blender, it has collision, wind emitter set up.

I made 3 variations as you can see in the middle of the picture, they are not very detailed, but instead they have very low poly count of around 250-350.

The preview picture is not rendered from blender its an ingame shot from Torque3D.

You can easily change the textures to make it look like something other, the trees are quite average for example the first one makes a good conifer-like tree with other textures.

Textures based on public domain images from burningwell.org and are included in the download.