Response from Prof. B.

What is the dimensionality in Winnie-the-Pooh anyway?

There is another smaller trompe l'oeil painting on the wall of a building at the corner of Bassett and Hospital Streets that is quite nice because of its location on a corner. You really have to get quite close to see that not only is the "bubble window" an illusion, but all the shadows on the brickwork are just painted there, accentuating the illusion of the part that is "out of place". I like things like that too.

I tend to agree that we don't have the same level of experience with slicing that we do with rotation. The slicing techniques therefore seem more "intellectual" rather than "gut feelings". We are quite used to the images of cubes, in straight-on views or in perspective, and we would be quite surprised if someone came up with a new one. But most people have not thought enough about slicing, and the hexagonal slice of a cube is something startling for a great many people.

We can do the Schlegel diagrams you want, at least in the simpler cases. Remind me to try to find them and show the class.

The Brisson hyperstereogram is meant to be fused all right, but only one part can be fused at a time, contrary to the usual cases where you get it all when it finally clicks. Maybe I can find some other examples from Brisson's work and that will make the concept clearer. No one understands it fully, yet.

Good link work.