If you want to make trees in video games, you can grab a program called SpeedTree and get to growing, pruning and playing god. This is what game developers do, including apparently the makers of Batman: Arkham City, whose game had trees I forgot about.
This is the kind of tech they're showing at the Game Developers Conference in San Francisco. SpeedTree isn't a new thing. It's a staple. But that doesn't make it any less exotic to those of us in the normal world who look at so much of video game creation as a kind of magic.