ArtiE-Fract – Interactive Evolution of Fractals


Fractal pictures have been considered as attracting artistic objects as they combine complexity and some ''hierarchical'' structure. The mathematical structure that supports these pictures provides indirect access to their characteristics and, therefore, allows shape manipulation and exploration. ArtiE-Fract is a user friendly software for the creation of fractal pictures based on an interactive evolutionary algorithm.

An Evolutionary Algorithm (EA) is used as a controlled random generator of pictures. The appropriate tool is interactive EA, i.e. an EA where the function to be optimised is partly set by the user, in order to optimise something related to the "user satisfaction". This interactive approach is not new: Karl Sims has extensively shown the power of the method in the framework of computer graphics. We extend this approach to the exploration of a fractal pictures space and improve its flexibility with the help of advanced interactive tools related to the specific fractal model we use.

ArtiE-Fract evolves a population of fractal pictures, and displays it via an interface. More precisely, these fractal pictures are encoded as sets of contractive non-linear 2D functions (affine and non-affine), defined either in Cartesian or polar coordinates. Each set of these contractive functions represents an IFS (Iterated Functions System), which is visualised as a particular 2D picture, its attractor.

In ArtiE-Fract the interaction is twofold :

The ArtiE-Fract interface has been carefully designed in order to give access to a wide variety of parameters. This, together with the two particularities of giving access to unusual fractal pictures (non-linear IFS), and allowing the user to interact at any time with the evolutionary process, make of this software a flexible and user-friendly artistic picture generation tool.

See also a quick overview of ArtiE-Fract (in french).