The science of how your brain translates 2-D images to 3-D

http://www.sciam.com/article.cfm?id=seeing-is-believing-aug-08
This article discusses the science behind our brain's visual interpretation of images. It also gives examples of how wildlife uses this to its advantage to hide or trick predators. Studies have shown that our visual interpretation of images is based on the assumption that light is always shining down on an object. A few illustrations in the article display how this works. The science of visual interpretation is complicated, but we are gaining more understanding on how our brain interprets images and the assumptions this complecated system makes.