
1. IntroductionIdea and purpose of this program is the calculation of threedimensional fractals. The calculated objects are twisted, freely in space floating (and  of course  fractal) "lumps" which look like made of dough  in contrast to what is normally called "threedimensional" fractals (namely a simple reinterpretation of the twodimensional data).The objects can be colored by linking space coordinates (or other parameters) to colors using a mathematical formula. The palette of colors can consist of up to 50 colors or color ranges. Additionally it is possible to define intersection planes. With this feature the internal construction of the fractals can be displayed. Of course, especially interesting is an intersection with the complex plane: you get the usual twodimensional fractal as intersection object how it could also be calculated by "Fractint" for example. Moreover it can be seen how different regions of the twodimensional fractal are connected together in threedimensional space. Screenshot of Quat 1.2 (under Linux): Normally, the the picture is calculated and saved in 24bit true color, but it can be displayed in 256 color during calculation (however in poorer quality). The fractals calculated with Quat correspond exactly to the usual, two
dimensional "julia sets", which almost every fractal program can calculate.
(Available iteration formulas are "Classical Julia" x_{n+1}
= x_{n}^{2}  c and "Lambda Julia" x_{n+1}=cx_{n}(1x_{n})
; x_{0} represents the pixel being calculated.)
Generation of a really three dimensional view is possible (3d stereo). The fractal can be seen three dimensional without any utilities like 3d glasses. The output format is the PNG format. It is the successor of GIF and offers  like GIF  compression of image data without loss of quality (JPEG compresses better, but the quality gets worse). More information on PNG: http://www.libpng.org/pub/png/. Because of the fact that PNG allows the storage of data specific to the application, Quat saves all data neccessary for the generation of the image within the PNG picture. Quat uses a library named "ZLIB" to write the PNGfiles. This library is a compression library and has nothing to do with fractal calculation. It was written by Jeanloup Gailly and Mark Adler. More information on ZLIB: http://www.zlib.org/ The user interface was implemented using the portable "Fast Light Toolkit"
(FLTK). The hompepage of this project is located at
Quat is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place  Suite 330, Boston, MA 021111307, USA. Special thanks to Max Schwoerer for the clarification of some of the
juridical questions, and to Oliver Siemoneit for his help on the English
translation. 1.1 What's new?Version 1.20:New features:
Version 1.11: (Jul/12/2001)No new featuresBugfixes:
Version 1.10: (Dec/14/2000)New features:
Version 1.01: (Aug/16/2000)Bugfix release:
Version 1.00: (Aug/7/2000)
Version 0.92: (Dec/7/1998 ; 0.92b: Oct/5/1999)
full functionality of hitherto (and still) existing initialization files can be reached through dialogboxes: There is an "Object Editor", a "View Editor", a "Color Editor", an "Intersection Editor" and a dialog for the remaining parameters. There now are also scroll bars when the image is larger than the window. The user interface is completely Windows style (ImageOpen, ImageSave, ImageSave As,...), which also means that much more memory is needed than before... Version 0.91: (8/2/1998)
now all the information can be kept in one file, but the old scheme is also possible by using the keyword "include <file>". Keywords "colorfile", "objectfile" and "cutfile" are no longer recognized (use "include" instead.) This feature is used to reduce moire patterns which disturb the image. Results in much better image quality in most cases! For more information, read paragraph 3.2 in this file. Version 0.90b: (14/9/97)
Version 0.90: (29/7/97)Initial version.1.2 System requirementsTheoretically none, if you are able to compile ANSIC/C++Code with your system... :)The requirements for the precompiled (binary) versions of Quat are:
1.3 Bugs and adresses, Mailing listIf you have some proposals for improving this program or if you want to report a bug, please send me an email (dirk.meyer@studserv.unistuttgart.de). I appreciate any feedback. If you like to (and are able to) program, you can send me your source code. I'll build it into future versions. (Of course I'll mention you as the author!) I have the model of "Fractint" in mind, maybe there are also some enthusiasts in this case!My postal adress is: Dirk Meyer Marbacher Weg 29 D71334 Waiblingen Germany New versions (and the sourcecode) of Quat are available at http://www.physcip.unistuttgart.de/phy11733/index_e.html There's also a Mailing List available, which is used to discuss artistical aspects as also technical and mathematical topics. You can look at an archive of old messages at http://groups.yahoo.com/group/quat/ To subscribe to the list and automatically receive all new messages, just send an email to quatsubscribe@yahoogroups.com 