An Illusion in which a 2-D drawing of an array of Cubes appears to simultaneously protrude and intrude into the page.
References
Fineman, M. The Nature of Visual Illusion. New York: Dover, pp. 25 and 118, 1996.
Jablan, S. ``Impossible Figures.'' http://members.tripod.com/~modularity/impos.htm.
Newbold, M. ``Animated Necker Cube.'' http://www.sover.net/~manx/necker.html.