Ultra Fractal 2 Resource List

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UF Formula Compilation

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The Challenges

Internet Fractal Database


Learning to use Ultra Fractal

The successor of Fractint

Ultra Fractal ,a program for generating fractals written by Frederik Slijkerman. , has been been adopted quickly by the people using previously Fractint,because of its compatibility with Fractint and its superior performance.

Try other people's par files

Perhaps this is the best way to learn.
For this you have to copy the parameters file and then to paste it inside the picture window of UF. That's all! This works also for parameters included in posts to the mailing list.The parameter file contains references to formulas used to compute (filename.ufm),to colore (filename.ucl) and to transform the fractal (filename.uxf).Filename usually is a acronym indicating the author of the formula collection.If a formula is missing, try the latest compilation of formulas here.

How to start

UF Resources list contains a list of very well done tutorials about using many features of this program like : layers,alpha channel,anti-aliasing,etc... Of course the program itself has a small online manual.It contains also a list of galleries of UF images where you can see examples of what can be done with this program.

How to select a rectangle in a image to zoom

The problem is that the selection box is a rectangle having the same aspect ratio of the window. So first make it big enough to contain the detail you want to zoom,then change width or height of the window,until the box contains exactly the part to zoom.

Who's Who

Using UF you will find frequently those acronyms.These point to the authors of the best formulas. So it is a good idea to look at their galleries and follow their postings to see if they have new formulas available.Someone offers also an up-to-date version of the formula collection to download.
AMC       Adam Clarke
ANON      anonymous or unknown author
BWP       Brian Prentice
DMJ       Damien M. Jones
FRACMOD   modified Fractint formulas by various authors
FS        Frederik Slijkerman
GFP       Gedeon Peteri
GWFA      G.W.F.Albretch
JP        Janet Preslar
LKM       Kerry Mitchell
LP        Luke Plant
PFJ       Peter Jakubowicz
PWC       Paul W. Carlson
KR        Kathy Roth
LA        Linda Allison
MAC       Marcelo Anelli (also MACP)
MT        Mark Townsend
OBSOLETE  formulas kept for compatibility, but made obsolete by newer versions
RBS       Robert B. Smith
REB       Ron Barnett
RM        Ray Montgomery
SAM       Samuel Monnier
SG        Sylvie Gallet
SM        Stefan Matthias
SP        Stig Petterson
STS       Stefan Schroeder
WK        Wayne Kiely

The Challenges

The Challenges were invented to explore the many capabilities of this program and can be used as a test to know if you really master it. You can compare your results with the entries of other people posted toghether with the challenges.

Testing new colouring formulas

With Ultrafractal are available many coloring formulas (.ucl files) and to use them correctly, it is important to understand the capabilities of these formulas. Said in simple words the difference between the fractal formula (.ufm file) and coloring formula is in the fact that the first formula will describe how the surface of the drawing must be tiled , the other what a single tile should contain. The simplest fractal is a spiral and here the tiles are composed by the same image that gets smaller and smaller. The content of the image is decided by the coloring formula. To understand the many available formulas I start always with the following very simple fractal formula using always the same palette and a small "Maximum Iteration" .

Learning to use layers

Layers are one of the most interesting feature of UF, but are also very difficult to use correctly.To help me I have invented a certain number of metaphors that will guide me.
  • Taking in account that the base layer is always opaque and serves as background, so the first metaphor is to have all layers completely transparent except for the zone containing the image.This can be obtained by defining the "outside solid color" as transparent and then positioning the image relative to the background.
  • The simplest way is to make each layer(except the background) partly transparent and see what happens(Merge mode=normal) by changing the % of transparency.
  • You can also load two near equal images and then by using merge mode on "Difference" play with the alfa channel and see if you can extract from the image some interesting pattern.
  • The alpha channel is very difficult to use but you can play by trying random settings. What you get is just a layer transparent only in some random set of pixels.
  • Use the gate,window,veil,frame,etc metaphor!
  • Merging a brightly coloured image without many details with a gray image with many details gives a 3D aspect to the combination(like a 3D transparent model of a machine).

Learning to use HSL gradients

In HSL mode, you can control better the color.Unfortunately HSL color coding is a lot more complex for newbies like me than RGB coding. To start understanding how it works, I suggest to define some colors in RGB and then see (CTRL-H) how they became as HSL.
The Hue goes in a circle from 0 to 360 and defines the color in the "color circonference" :0 is red,60 yellow,120 green,180 cyan,240 blue ,320 magenta. With 360 you go back to red.Saturation is 255 for pure colors. If you decrease it ,you add grey to the pure color "muting" it more and more.At the end (Saturation=0) you get a perfect gray. If you use the Windows color chooser you see clearly how Hue and Saturation define color in the big rectangle on the right:hue changes horizontally, saturation vertically. You can see neatly the pure colors becoming more and more gray.
Luminance is normally at half value(128):decreasing it you get darker colors up to black,increasing it lighter colors up to white. Choosing one of those bright palettes used by Paul Carlson can be a good starting exercise to master the HSL gradient(see the upr of this image). The Saturation is set to maximum for all points (i.e. we want full colors). Then for each of the 8 main colors we select a Hue,and then let change the Luminance from 128 to 24. In this way we get brilliant colors that go from full color to a darker one indicating a kind of shade.
Maintained by Giuseppe Zito: Last modified: