PC Shareware 1997 May/PC Shareware 1997-05.iso/programy/diffract/readme.txt

Text File | 1996-07-07 | 9.2 KB | 169 lines

Diffract - Version 1.3 - for Windows 95 only - 7/7/96

   David Bleecker
   1440 Kapiolani Blvd #108-138
   Honolulu, HI 96814


   email: [e-mail]


The idea behind Diffract:

This program generates color-enhanced pictures of diffraction patterns, which
I will call diffractals. One might guess that a diffractal is some kind of fractal,
but this is not quite correct. If you have ever looked through a toy microscope
on high power, you must have noticed the wild colorful speckled patterns and rings
which resist any attempt to focus. Have you noticed the strange patterns of a street
lights through the finely rippled glass of a bathroom window? These too are diffraction
patterns. They are caused not only by cheap lenses, rippled glass or poor eyesight, but
also by the inherent wave-like nature of light.

A more complete explanation of the physics:

When light waves flow around an object or through lenses, they bend and interfere
with one another. The extent of bending depends on the color or wave-length of the
light. Expensive achromatic lenses compensate for this by focusing different colors
by different amounts, to produce a nearly naturally colored image. However there is a
fundamental limit to the power of even the most perfect optical microscope. Essentially,
one cannot resolve objects which are not much bigger than the wavelengths of visible
light. Instead, as power is increased, one observes more pronounced diffraction
patterns resulting from the disturbance of the waves by small objects. Quantum theory
tells us that all particles (e.g., electrons, protons, etc.) have wavelike attributes.
Electron waves have a much shorter wavelength than light and hence electron microscopes
can resolve much smaller objects, but again there is a limit. On a sufficiently small
microscopic level, one is tempted to say that the universe is a menagerie of interacting
waves and diffraction patterns. Actually, things are more complicated than that. Indeed,
there is another perspective in which particles are essentially point-like (or
string-like), but their positions are statistically governed by a probability cloud
which resembles a (possibly evolving) diffraction pattern. However, now we are
approaching the limit of what can be understood in a mundane way, without mathematics.
Let it suffice to say that the natural appearance of diffractals is due to the
fact that they are built into the fabric of the universe.


The Diffract Program:

Each pixel is colored according to a complex algorithm (and some parameters
that you enter) with one of up to 16,777,216 colors depending on your video card
(i.e., the output is true-color if you have it, and the best possible, if you don't).
Thus, the output is generally of much higher quality than you find with popular
fractal programs which are usually limitted to 256 colors per pixel. Also,
diffraction patterns are not fractals. Generally, they are more lifelike, natural
and flowing, and it is relatively easy to choose parameters which generate
prettier results than your average fractal. However, you will probably agree
that this is an understatement.

Installation and Starting:

Besides this file, there is only one crucial file - diffract.exe, and some sample
data files (*.dff) are included. Include this file (unaltered) as well, if you
want to distribute or upload the program.

No installation is necessary. Just run the program from within
Windows 95, say by double-clicking in Explorer, even if the program
resides on a floppy. Of course, one may wish to copy the files to an
empty folder on the hard drive. Simply delete the folder and its contents
to uninstall without a trace left behind.


Legalities:

Version 1.3 of Diffract is copyrighted freeware. Attempts to sell or distribute
the program for commercial gain must be approved me. If you find the program of value,
and you want to support my efforts to improve it, donations (however small) will be
appreciated. With a donation of $20 or more (check to David Bleecker or cash) sent to

                   David Bleecker
                   1440 Kapiolani Blvd #108-138
                   Honolulu, HI 96814

I will try my best to implement a feature that you want added, or cure a behavior
that irks you. I will attach the resulting improved latest version to an email to you,
or explain why I've failed and send you the latest version anyway. Please give me a
few weeks. In case you have trouble receiving email with zipped attachments, I can
send the zip file on a disk. Please report any problems you are having. As far as I know,
there is no damage that the program can possibly do. However, if you use the program, you
must agree to hold me blameless for any mishap. Diffract was developed using Microsoft
Visual C++, Version 4.0.


Basic instructions suggestions and comments:

1.  The window should be sized small for fast generation. After resizing the
window, left-click the mouse inside the window to redraw the image to the
new window size. Subsequent left-clicks zoom the window by 200% centered about
the point which was clicked (see item 3 below). Right clicks always zoom out (50%).
Also, increasing the scattering factor in the Settings/Misc dialog box will
increase speed but may adversely affect the image. Features can change shape if
zoomed when the scattering is set high.

2.  Experiment with different color settings in the Settings/Frequency
dialog box. Make sure the color radio button is on, unless you want
gray-scale. Also, try different types in the Settings/Pattern dialog box.
Before creating your own masterpiece from scratch, try loading some of
the included  dff  files from the File/Open dialog box.  You may wish
to use these files as a starting point when you change the settings.

3.  Zoom in on an object with a left mouse click on the object. You will
have to uncheck the center horizontal and vertical boxes in the Settings/Misc
dialog box to zoom in on an off-center object. When checked, these boxes
constrain movement to a vertical or horizontal line through the center of the
default pattern for the given type. Zoom out (50%) with a right mouse click.
To pan out of the window, zoom in near an edge and immediately zoom out. Then
you've panned by half a window.

4.  When you've got a winner, enlarge the window to the desired size and
left-click in the window to begin generation of the image to fit the window.
One can minimize the window, while the image is being computed in the background,
and you can work on other applications. When an image is complete, it is a good
idea to immediately copy it to the Windows clipboard (via Edit/Copy or Ctrl + C).
Start a paint program such as Paint Shop Pro (if one is not already running) and
paste the image from the clipboard into the paint program. You can then process
the image and save it in the format of your choice. The resolution of images produced
by Diffract are the highest possible for your display. If you want to stretch a
small image (thereby introducing blockiness and jaggies), you may resize it in a
suitable paint program. However, unless you are short on time, memory or disk space,
just generate a larger image by resizing the Diffract window and left-clicking
in the window.


5.  When you find something nice, you will want to save the settings in a
*.dff  file for future use.


Advanced comments:

1. Higher frequencies make for more delicate details. Since zooming makes
details larger, you may wish to raise the frequencies after zooming many times.

2. If the RGB color frequencies are set equal, a much more focused image
results. One can then get different colors by making the RGB contours and/or
edges different. Also, if the RGB color frequencies are set equal, image
generation is about three times faster than if they are all different. Even
if only two RGB color frequencies are equal, image generation is 50% faster.

3. Contours produce bands of smoothly changing colors. The higher the contours,
the more bands are obtained. Edges (if set greater than 1) produce abruptly
changing colors and intensities. You may find it challenging to produce colors
that you want. Generally, one can suppress a color by setting its contour
to a value less than 1, but often it is easier to paste the image in a paint
program and change the colors and introduce other effects using the filters
of your paint program.

4. Polarization values (in the Settings/Misc dialog box) further from zero
tend to produce a wider variety of shapes.

5. Experience may eventually lead you to produce desired effects, but more
often you must simply appreciate that what you get is typically stranger
(and perhaps better) than what you imagined. Often you can find some pattern you
like by panning and zooming in on some intriguing detail. Changing the texture
dilation in the Settings/Misc will shift the colors somewhat, without changing
the shapes too much.  If you've got something you like, you probably don't want
to make any big changes in any of the settings. When you happen to get colors
and/or patterns you like, save to a  dff  file with a descriptive name to recall
the settings for later use.

Enjoy!