SITE TOOLS Flattening and Optical Indexing
When you first used your pencil as a measuring device, you extended your arm and closed one eye. Why did I ask you to close one eye? Try it with both eyes open. It doesn’t work. It takes both eyes to have depth perception, which you don’t want, because you’re drawing on a two-dimensional piece of paper. Closing one eye flattens the world around you. Aha! You’ve just established a drawing technique! To draw a three-dimensional image on a two-dimensional piece of paper, you must close one eye.
If I make an imaginary line straight down from the eye in this photograph, it will bring me to ...