Editing Depth perception (section)

=== Kinetic depth effect ===
{{main|Kinetic depth effect}}
If a stationary rigid figure (for example, a wire cube) is placed in front of a point source of light so that its shadow falls on a translucent screen, an observer on the other side of the screen will see a two-dimensional pattern of lines. But if the cube rotates, the visual system will extract the necessary information for perception of the third dimension from the movements of the lines, and a cube is seen. This is an example of the ''kinetic depth effect''.<ref>{{cite journal|last=Wallach|first=H.|author2=O'Connell, D.N.|s2cid=11979303|title=The kinetic depth effect|journal=Journal of Experimental Psychology|year=1953|volume=45|pages=205–217|doi=10.1037/h0056880|pmid=13052853|issue=4}}</ref> The effect also occurs when the rotating object is solid (rather than an outline figure), provided that the projected shadow consists of lines which have definite corners or end points, and that these lines change in both length and orientation during the rotation.<ref>{{cite book|last=Kaufman|first=Lloyd|title=Sight and Mind|year=1974|publisher=Oxford University Press|location=New York|pages=139–141}}</ref>