Escher was able to discover such tilings through a combination of natural ability and sheer determination. Can we automate the discovery of tilings by recognizable motifs? More formally, we pose the Escherization problem:
Given a shape S, find a new shape T such that:
 T is as close as possible to S; and
 Copies of T fit together to form a tiling of the plane.
We have developed an algorithm that can produce reasonable solutions to the Escherization problem. It is based on three large components:
Here are some images produced using Escherization. Click on each one for a fullsize version.
A Plague of Frogs 
Dogs; Dogs Everywhere 
Teassellation 
Tuxture Mapping 
Twisted Sisters 
Wiener Dog Art 
Escher also created a number of dihedral tilings: designs featuring two different shapes. He was fond of these designs, since with more than one shape it was possible to tell a story, to have the shapes complement each other somehow.
The Escherization problem can be adapted in an obvious way to two goal shapes. We can also extend the space of tilings by including in the parameterization a path that splits an isohedral tile shape into two pieces. We compare the two pieces to the goal shapes and run the optimization as before, attempting to minimize the maximum of the two comparisons.
Gödel, Bach (Braided): An Eternal Escherization 
Funky Chickens 
The Owl and the Pussycat 
Pen/Rose Tiling 
Rembrandt and Mrs. van Rijn 
Strange 'Tractors 
Dihedral Escherization can also be exploited to create designs in the style of Escher's Sky and Water. We need to restrict the search to a narrower class of possible tiling types (what Dress calls “Heaven and Hell Patterns”). Once the desired tiling has been discovered the rest of the process is fairly easy, since we already have an association between a realistic, usersupplied goal shape and an abstract, more geometric tile shape. We just need to morph between those two extremes. Here's one example, based on Rembrandt and Mrs. van Rijn above.
The Penrose tilings P2 (kites and darts) and P3 (thin and thick rhombs) can also be parameterized and fed to the Escherization system. It's much harder to discover satisfying results, because of the idiosyncratic shapes of the Penrose tiles. It's exciting to be able to produce these aperiodic pictures – Penrose and Escher were friends, but sadly Escher passed away before Penrose discovered P2 and P3. Penrose has asked what sorts of designs Escher would have been able to create from these tilings.
A Walk in the Park 
Busby Berkeley Chickens 
The Pentalateral Commission 
You might enjoy playing with the edges of Penrose tiles to see whether you can produce recognizable shapes. I've created a Java applet that lets you do so interactively.
Escher made four wonderful Circle Limit patterns, designs based on nonEuclidean geometry. Escher didn't have the mathematical background to manipulate hyperbolic patterns symbolically, but he certainly had the intuition necessary to create pictures of them.
Our Escherization algorithm cannot easily be translated into nonEuclidean geometry, for deep reasons having to do with the notion of shape, as used in the shape comparison metric. However, for some isohedral tiling types it is possible to transfer the output of Escherization from the Euclidean plane to the hyperbolic plane or to the surface of a sphere. The process is a kind of nonlinear warp of a piece of the Escherized tiling.
Circle Limit V 

Hyperbolic Teapots I 
Hyperbolic Teapots II 
Spheres on a Teapot, Teapots on a Sphere 
I have also made a Java applet that allows you to explore the space of Penrose tile shapes interactively. It's a fun way to play with this rather mysterious tiling. Most of the effort related to aperiodic tilings seems to be related to their combinatorial properties, without considering the actual shapes that can be produced. You can try the applet here.
All final tilings are copyright 2000 by Craig S. Kaplan. You are free to use them for personal and noncommercial purposes. Please check with me about any other uses.Craig S. Kaplan  Last updated: 