In a previous article on this blog have been showed two methods, one geometric and one analitical, for molecule construction in flagstone tessellations.
More in detail, the geometric method can be easily used in a vector graphic software (such as Inkscape) in order to design a flagstone molecule with assigned shape and dimensions.
However, if we want to design a full flagstone tessellation, made up, for instance, of several different flagstone molecules, then the use of the method may became time-consuming,
as a consequence of the increasing number of steps needed to complete each molecule.
Hence the need for a tool able to automatize these steps and to directly provide the final crease pattern of the desired molecule.
That is, the OriFlagTess software.

In plane geometry, the term tessellation indicates the covering of the plane with one or more geometric figures (called "tiles") repeated infinitely, without overlapping and without spaces between them.
Similarly, in the origami world, all those models formed by equal (or even similar) "tiles" that are repeated in the surface are called tessellations.
Each tessellation is always made from a single sheet of paper properly folded.
Unlike geometric tessellations, the tessellations can be both flat and three-dimensional.

For some time now, I've been reviving my old interest in the art of folding paper, better known as "Origami".
Specifically, I started again when, by chance (or maybe not), I came across the works of various artists, such as Robert J. Lang, Tomoko Fuse, Ilan Garibi and others.
It was clear that I had missed a few "steps", and it was time to catch up.
Let's see what this is about.

Origins

The new course of origami, or Origami 2.0 as I like to call it, has developed gradually since the 1930s, thanks to the work of the Japanese Akira Yoshizawa, the father of modern origami.
Yoshizawa introduced innovative techniques both in the design and in the realization of his works, many of which are still used today.
For example, he was the first to create four-legged animals ^{1} and to give three-dimensionality to his creations.
He invented the wet-folding technique (see dedicated section), now used in many forms and variations by all experienced origamists.
Last but not least, he introduced most of the symbolic notation used today to describe the folds of an origami model, known as the Yoshizawa-Randlett system.
Starting from the 50's Yoshizawa's works started to be known outside of Japan, and so other artists started to be interested in this new more expressionist conception of origami; in this case we remember the British Robert Harbin, but above all Neal Elias, first to use and popularize the technique of box-pleating,
well known and relevant today, among the origami techniques.