Geometric Art: Circle for Kids, Delaunay Triangulation, iPad Apps
Circle
A circle is the set of all points in a plane that are at a given distance from a given point,
called the center.
Trimaginator for iPad and iPhone by Paul Ollivier
Trimaginator is inspired by the triangulation invented by the mathematician Boris Delaunay in 1934.
While the process behind is complicated, the image is reduced to its essentials and turned into a triangle mesh.
Delaunay Triangulation
A Delaunay triangulation for a set P of points in the plane is a triangulation such that no point in P is inside the circumcircle of any triangle in the triangulation. It can be shown that for all possible triangulations of P, a Delaunay triangulation maximizes the minimum angle of all angles of the triangles in the triangulation. Thus, a Delaunay triangulation tends to avoid skinny triangles. 
Recent Additions
