# Kokichi Sugihara

Professor of Mathematical Engineering

Meiji University

Tokyo, Japan

Kokichi Sugihara is a professor of mathematical engineering at Meiji University. One of his research areas is computational approaches to visual illusions. He has created many solids that realize pictures of impossible objects, and has also created a new type of visual illusion called “impossible motion,” in which we perceive physical motion that looks impossible. He won first prize in the Best Illusion of the Year contest twice. One was in 2010 for his illusion artwork, “Magnet-Like Slopes,” and the other was in 2013 for another illusion artwork, “Rotation Generated by Translation” (created with two co-authors). He is the leader of the research project “Computational Illusion,” sponsored by the Japan Science and Technology Agency.

Line Dance of UFOs

20 by 24 (inches)

Illustrator

2013

This is a still picture, but it looks as if the UFOs are moving. Actually, when we move our eyes horizontally, the UFOs move vertically, and when we move our eyes vertically, the UFOs move horizontally. This picture was created based on a mathematical model of the human visual perception process.

Eccentric Ring Toss 2

15 by 15 by 15 (inchies)

three-dimensional solid made of plastic

2011

This is a solid that generates the visual impression of an impossible object when it is seen from a specific viewpoint. When we see it with one eye from the specific viewpoint, we perceive an object consisting of a vertical column and four perches extending horizontally by mutually right angles. The red square ring passes behind the vertical column, but at the same time passes in front of all the four horizontal perches; thus it generates the illusion of an impossible object. This shape was created by a system of equations for reconstructing three-dimensional objects from a two-dimensional picture.

Bee and Stag Beetle

24 by 24 (inchies)

Generated by my computer program

2013

This is an example of figure-ground reversal tiling art. The bee at the top deforms gradually downward, melting away into the background, and another shape appears from the background and becomes the clear shape of a stag beetle at the bottom. The mathematical structure of this tiling pattern is the same as Escher's artwork, "Sky and Water I" (1938). I gave the top bee and the bottom stag beetle to my computer program, and the program generated the intermediate tiles and their placements.