This video has now gone viral with over 200,000 hits on YouTube since it's release this August. And I can see why! The researchers at the Technion - Israel's famous Institute of Technology, have used their own Objet 3D printer to re-create the impossible Escher Drawings as real, tangible 3D models.
Particularly intriguing is the 3D printed Belvedere (below), first produced as a 2D drawing in May 1958. In his original work, Escher drew a rectangular three-story building supported by a number of pillars that, at first glance, appears to be plausible. But on close inspection you see that those supporting pillars at the front appear to be supporting the back side of the top floor while those at the back appear to be supporting the front - an obvious paradox. You can see how this is solved in the "real" 3D world - by the clever manipulation of the viewer's perspective...
For more on this project see Professor Gershon Elber's 'Escher for Real' project at the Computer Science Department, Technion.
[caption id="attachment_9070" align="alignright" width="379"] Objet 3D Printed Escher Model in Rigid White Material[/caption]