[visionlist] geometrically ambiguous images

[Bart Anderson]

> (1) are there any geometrical images which are TRIPLY ambiguous in  
> the way
> that the Necker Cube is doubly ambiguous, where the transitions  
> between
> ambiguities are obvious, regular, and spontaneous (i.e. not  
> dependent upon
> "effort")?

If you are asking if there are images that are tri-stable in the way  
that the necker cube is bistable, then the answer is yes.  Probably  
the simplest example if an image containing an array of equilateral  
triangles, placed randomly on a page with the same orientation.  The  
triangles can all be seen to "point" in a particular direction that  
spontaneously shifts between the 3 directions of the triangles'  
vertices.