Kinetic Depth Effect

The kinetic depth effect is a visual phenomenon in which information projected onto a two-dimensional screen provides the illusion of three-dimensional structure provided the projected information is dynamic (i.e. the projection of a moving object). It was discovered by Wallach and O'Connell (1953), who projected the shadow of a rotating wire frame structure onto a screen. The rotating shadow produced the sensation of seeing the 3D structure of the object. However, it was an illusion in the sense that the direction of rotation of the experienced 3D structure would reverse while watching.

The kinetic depth effect is related to the ability to see the 3D structure of moving objects, such as dancing humans, when all that is visible are a handful of moving dots (Johansson, 1950). Our ability to experience the kinetic depth effect indicates that the visual system can solve the structure from motion problem that was formally investigated by Ullman (1979).