Coloring
Methods and Formulas
Prior to the introduction of UltraFractal, most popular fractal generating programs bundled a formula together with a coloring method. In the early days of the DOS program Fractint, only a limited number of coloring methods such as the standard and decomposition were available. However, mathematician artists were writing their own code which applied startlingly beautiful coloring methods to the tried and true formulas like the Mandlebrot or Julia sets. With the release of version 19.6 of Fractint, these coloring methods could be added to formulas. While this opened up a vast new range of possibilities, the artist was still stuck with a coloring method specific to a formula. In parallel development, Windows programs were beginning to separate the formula from the coloring method so that they could be re-combined at the users behest. But the range of available formulas was severely limited. UltraFractal brought forth the first popular departure from Fractint and offers a broad range of formulas and coloring methods, each independent from the other. Those who like to write formulas and coloring methods can add to the ones which come with UltraFractal and a staggering number are now available for download by following links from Janet Preslar's UF Resource page.
I think of a fractal formula as a method of plotting which generates
a graphic by telling the computer, put a blue dot (pixel) here, put
another yellow one there, etc. The arbitrator of where the
pixels go is a mathematical formula just like the ones we learned in geometry
class. The most famous formulas are the Mandelbrot and Julia sets
which looks like this
The Mandelbrot Set |
The Julia Set |
But there are as many possibilities available as there are formula writers.
Here are a couple of formulas from Gedeon Peteri
gfpcau02 |
gfpstr01 |
As you can see, a formula radically alters the shape of the fractal.
These examples use the default coloring method "none" whose name is something
of a misnomer. It is not the absence of a coloring method, but the
simplest one and the one used by Fractint, so perhaps the most familiar.
What you see is a general idea of the shape generated by the formula with
the coloring method instructing UF which color to use for each pixel.
The shape can be enhanced by selecting a different coloring method as I
do below.
Julia with cardioid coloring |
gfpcau02 with cardioid coloring |
When you compare the version of the formula using "none" with the version using the new coloring method notice that
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