Francesco De Comité
Manipulation of digital images, and use of ray-tracing software can
help you to concretize mathematical concepts. Either for giving you an
idea of how a real object will look or to represent imaginary
landscapes only computers can handle.
Things become yet more interesting, when you can transform your
two-dimensional dream objects in real three dimensional sculptures.
You can then handle your creations, and look at them from an infinity
of view angles.
Dupin cyclide are images of tori under inversion. They can be described by means of several families of circles. Villarceau circles give an attractive underline of those structures. After having completed the wireframe version on the left of the picture, I realised it could have been done with interweaving strips. The shape of each strip is different (modulo symmetries), and are just approximation, since this surface is not developable. The programming challenge was part of the game.
Following the directions shown by D'Arcy Thompson (for the shapes and growth of shapes), and Meinhardt (for the generation of shell patterns), I wrote a program that can generate a large range of existing seashells. The program is written in such a way that one can cross shapes from one kind of shell with pattern from another one. Finally, I designed the escheresque pattern at the bottom of the picture.