have a large collection of fractal coloring
algorithms implemented as FractInt formulas. Currently
over 120 formulas are in this file. (There is also
an Ultra Fractal 2
version.)
Please note: these formulas use IF ,
which is supported in FractInt 19.6 and later. If your
version of FractInt is earlier than this, these
formulas will not work. Go to the
FractInt
web pages and download a more current version.
dmjpub.zip
15K; formula files and examples
UnZIP the file to your FRACTINT
directory. If you've modified your SSTOOLS.INI
file to specify a location for your FRM
and PAR files, you will need to move
the unZIPped files to the proper locations. If
you don't know what SSTOOLS.INI is,
don't worry—unZIPping to your FractInt
directory should be sufficient. The dmjpub.txt
file contains a brief introduction to using the files.
There are so many formulas in this collection that it's
hard to know where to start. To help with this, I have
included twelve examples of images created with these
formulas (most of which are also displayed in the
1998 and 1997
galleries here). To
view these, start FractInt, press @ , press
F6 , select dmjpub.par and
press RETURN . Scroll down to the end of
the list and choose any of the parameters starting
with ex . These are the examples.
Many of the formulas in this collection benefit from
having certain parameters set that are not immediately
obvious. Getting around this problem is why I've
included a PAR file in the first place.
To start fresh with one of these formulas, select it
from the PAR file. This will set the
correct starting location and any other parameters
that the formula needs to operate correctly.
To fully explore the richness of these formulas (now
doesn't that sound pompous) you should feel free to
fiddle with the options on the z screen.
If you don't care to know what they do, and just
want to mess around, you can skip the rest of this
document.
Because there are so many formulas, I have used a
simple naming convention to help you find the formula
you want. Here is a sample name:
dmjMandPntDstI
The name is broken up into segments, each separated
by a dash ( ). The first segment (dmj )
is present on all the formulas; this is so that if
you use ORGFRM to organize your formulas, they all
stay together.
The second segment indicates the fractal shape.
Because of how coloring algorithms have to be
implemented in
FractInt, every coloring algorithm must be tied in
to a specific fractal shape. In this collection I
have applied most of the coloring algorithms to
both the Mandelbrot set (Mand ) and
Paul Derbyshire's NovaM fractal (Nova ).
A few algorithms are only available for the Mandelbrot
set.
The third segment indicates the orbit trap type,
or the general coloring algorithm. Most of the
formulas included are orbit trap variants. Orbit trap types include point
(Pnt ), hypercross (Hyp ),
circle (Cir and Cr2 ),
cross or "plus" (Pls ), rectangle
(Rct ), and spiral (Spi ).
Nontrap types include smooth iteration coloring
(Smooth , SmoothPHC ,
and SmoothX2 ), triangle inequality
(Triangle ), and average angle
(ThetaW and ThetaW2 ).
The fourth segment (present only for trap types)
indicates the coloring method used with the orbit
trap. Several methods are available: closest
distance to trap (Dst ), angle to
trap of closest approach (Ang ),
angle of point relative to origin of closest
approach (Dec ), and iteration of
closest approach (Itr ).
The last segment, I , if present,
indicates that the formula will color the inside
portions of the fractal with the same algorithm
as the outside. Sometimes this can produce
great results, but keep in mind these types will
generally run slower.
Most of the formulas use parameters the same way.
This will make it easier for you to learn which
parameters do what. Here is a summary for the
orbit trap types:
p1: location of orbit trap center.
p2r: rotation angle of trap, in degrees.
p2i: trap aspect ratio, height:width (not for Hyp ); for Spi , minimum iterations.
p3r: color scale (Dst only).
p3i: circle diameter (Cir and Cr2 ) or bailout.
Nonorbit trap types generally only use p3r
and p3i from the above list.
