Editing Impossible object (section)

==Constructed impossible objects==
Although possible to represent in two dimensions, it is not geometrically possible for such an object to exist in the physical world. However, some models of impossible objects have been constructed, such that when they are viewed from a very specific point, the illusion is maintained.  Rotating the object or changing the viewpoint breaks the illusion, and therefore many of these models rely on [[forced perspective]] or having parts of the model appearing to be further or closer than they actually are.

The notion of an "interactive impossible object" is an impossible object that can be viewed from any angle without breaking the illusion.<ref>{{cite web |first1=Chih W. |last1=Khoh |first2=Peter |last2=Kovesi |url=http://www.csse.uwa.edu.au/~pk/Impossible/impossible.html |title=Animating Impossible Objects |date=February 1999 |access-date=10 February 2014 |archive-url=https://web.archive.org/web/20150528135957/http://www.csse.uwa.edu.au/~pk/Impossible/impossible.html |archive-date=28 May 2015 |url-status=dead }}</ref>

{{Wide image
|Perth Impossible Triangle.jpg
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|As the  viewing angle changes of this sculpture in [[East Perth]], Australia,  a [[Penrose triangle]] appears to form.|Impossible triangle sculpture as an [[optical illusion]], East Perth, Western Australia|dir=rtl}}