Steven Pinker -- How the Mind Works - Hampshire High Italian ...

232 HOW THE MIND WORKSrepeat themselves every eleven spaces. (The stuffed rows, you willnotice, are longer than the rest.) Copies that are more widely spacedequals a surface that is more distant. A real random-dot autostereogram,of course, is made of dots, not numbers, so you don't notice the snippedoutor stuffed-in material, and the uneven lines are filled out with extradots. Here is an example. The fun in viewing a real random-dotautostereogram is that the moment of pop-out surprises the viewer withpreviously invisible shapes:When the autostereogram craze hit Japan, it soon developed into anart form. Dots are not necessary; any tapestry of small contours richenough to fool the brain into locking the eyes on neighboring stripeswill do. The first commercial autostereograms used colored squiggles,and the Japanese ones use flowers, ocean waves, and, taking a leaf outof Ames' book, leaves. Thanks to the computer, the shapes don't haveto be flat cutouts like in a diorama. By reading in the three-dimensionalcoordinates of the points on a surface, the computer can shift every dotby a slightly different amount to sculpt the solid shape in cyclopeanspace, rather than shifting the entire patch rigidly. Smooth, bulbous