Photo-montage
Niko Papist (npapist)
These images of impossible triangles were took from 3 meter distance with focal length 400mm and aperture f/45, more like a macro, otherwise the dice in the front is much bigger than the dice in the back. Then they were simply compounded by Photoshop Elements Photomerge-group-picture.
Artist's Flickr photostream http://www.flickr.com/photos/entendriver/.
Images were found at