"One of the funny things that we discovered was that because they don't look like trees or animals that we understand or relate to directly, you have to create, based on Seuss' illustrations, something that's believable. Because the Truffula trees are beautiful -- they look like cotton candy. But, by the same token, you have to create something that the audience feels something for. So it can't just feel like Candy Land; you have to buy it as a real forest. So we looked at Birch trees and then figured out how to make those wonderful illustrations work in a 3-D movie. It's a real fantasy forest that you could relate to when it's being chopped down."