SpeedTree was developed to create trees to be used within game engines. You not only model the trees but, you also set parameters for wind and other natural forces.
The trees have a low poly count and rely on textures to provide realism.
They can be exported as object files and imported into Terragen with a little work.
The Demo version of SpeedTree 5.0 eliminates every 5th poly on the model leaving holes in the tree geometry.
Marc
NOTE: Yes, this is standalone.
