135 lines
5.3 KiB
HTML
135 lines
5.3 KiB
HTML
<!--startcut ==========================================================-->
|
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
|
<HTML>
|
|
<HEAD>
|
|
<title>Ray-Traced Backgrounds LG #41</title>
|
|
</HEAD>
|
|
<BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#0000AF"
|
|
ALINK="#FF0000">
|
|
<!--endcut ============================================================-->
|
|
|
|
<H4>
|
|
"Linux Gazette...<I>making Linux just a little more fun!</I>"
|
|
</H4>
|
|
|
|
<P> <HR> <P>
|
|
<!--===================================================================-->
|
|
|
|
<center>
|
|
<H1><font color="maroon">Ray-Traced Backgrounds</font></H1>
|
|
<h4>By <a href="mailto: layers@marktwain.net">Larry Ayers</a></h4>
|
|
</center>
|
|
<P> <HR> <P>
|
|
|
|
<center><h3><font color="maroon">Introduction</font></h3></center>
|
|
|
|
<p>Ever had the feeling that your CPU, able to execute floating-point
|
|
calculations with lightning speed, isn't working hard enough as it idly coasts
|
|
along? A new automatic ray-tracer called Raychase will remedy this situation.
|
|
A Dutch programmer known as flux, who seems to be associated with a company or
|
|
organization called Squashed Rabbits, has released a multi-platform
|
|
"random recursive ray-tracer" which will periodically render
|
|
desktop or web-page backgrounds, either tiled or full-screen. It is intended
|
|
to be run continuously; on my low-end Pentium machine a new desktop background
|
|
is generated every three or four minutes. Flux, when asked the question
|
|
"What is the purpose of Raychase?", answered:
|
|
<blockquote>
|
|
Create pretty & wacky pictures - arty farty stuff - eye candy -
|
|
you name it - sorta ...
|
|
</blockquote>
|
|
|
|
<center><h3><font color="maroon">Installation and More Details</font></H3>
|
|
</center>
|
|
|
|
<p>Installation of Raychase consists of nothing more than unpacking the tar.gz
|
|
archives (there are two, one containing datafiles and the other binaries) in a
|
|
convenient location. Two executables are included, an optimized fast-running
|
|
one called <i>raychase.fast</i> and a slower debugging version,
|
|
<i>raychase.debug</i> which will output copious messages to the console while
|
|
it is running.
|
|
|
|
<p>Raychase makes use of a variety of pigment settings, graphic filters, and
|
|
preset templates which are chosen randomly for each successive image. These
|
|
generated images aren't completely random, though. They remind me of images
|
|
from science fiction movies; shaded spheres, lens-flares, and odd textures
|
|
abound. They could be called geometric abstractions. Here is a typical
|
|
rendering:<br>
|
|
|
|
<p><img alt="Raychase Image" src="./gx/ayers/ray.gif">
|
|
|
|
<p>
|
|
<p>and here is another:<br>
|
|
|
|
<p><img alt="Raychase Image" src="./gx/ayers/ray2.gif">
|
|
|
|
<hr>
|
|
<p>Raychase's behavior is controlled with command-line options. The command<br>
|
|
<p><b><kbd>raychase.fast -e</kbd></b>
|
|
|
|
<p>will generate fullscreen desktop backgrounds, while the command<br>
|
|
|
|
<p><b><kbd>raychase.fast -e -x64 -y64</kbd></b>
|
|
|
|
<p>will tile the desktop background with 64x64 tiled images. Naturally the
|
|
smaller images render faster; a background which changes every few seconds
|
|
would be distracting, but running Raychase this way for a while will provide a
|
|
demonstration of the different types of images. It's also possible to run
|
|
Raychase without a display, with the images saved to PPM files. As an
|
|
example, this command will save 640x480 images to the <kbd>/tmp</kbd>
|
|
directory:<br>
|
|
<p>
|
|
<b><kbd>raychase.fast -x640 -y480 -d -s /tmp/%04d.ppm</kbd></b>
|
|
|
|
<p>A command such as this could be used to save files to a cgi-bin directory
|
|
where they could be used as a source of periodically changing web-page
|
|
backgrounds.
|
|
|
|
<p>You don't have to run Raychase randomly. There are command-line options
|
|
which allow you to specify the filters and pigments. Even the faster binary
|
|
outputs a certain amount of status information to the console, so the
|
|
variables randomly chosen to generate a particular image are accessible and
|
|
could be re-used as command parameters.
|
|
|
|
<center><h3><font color="maroon">Availability</font></h3></center>
|
|
|
|
<p>The current home site, from which binaries and data-archives can be
|
|
obtained for a variety of operating systems (including both libc5 and glibc
|
|
flavors of Linux) is this
|
|
<a href="http://www.geocities.com/SiliconValley/7845/">web-page</a>.
|
|
|
|
Raychase at this time is a binary-only application, but there is a chance that
|
|
at least a portion of the source-code will be released in the future.
|
|
|
|
<hr>
|
|
|
|
<center>
|
|
<h5>Copyright © 1999, Larry Ayers <br>
|
|
Published in Issue 41 of the Linux Gazette, May 1999</h5>
|
|
</center>
|
|
<p>
|
|
|
|
<hr>
|
|
<!-- hhmts start -->
|
|
Last modified: Sat May 1 12:09:14 CDT 1999
|
|
<!-- hhmts end -->
|
|
|
|
<!--===================================================================-->
|
|
<P> <hr> <P>
|
|
<center><H5>Copyright © 1999, Larry Ayers <BR>
|
|
Published in Issue 41 of <i>Linux Gazette</i>, May 1999</H5></center>
|
|
|
|
<!--===================================================================-->
|
|
<P> <hr> <P>
|
|
<A HREF="./index.html"><IMG ALIGN=BOTTOM SRC="../gx/indexnew.gif"
|
|
ALT="[ TABLE OF CONTENTS ]"></A>
|
|
<A HREF="../index.html"><IMG ALIGN=BOTTOM SRC="../gx/homenew.gif"
|
|
ALT="[ FRONT PAGE ]"></A>
|
|
<A HREF="./jenkins9.html"><IMG SRC="../gx/back2.gif"
|
|
ALT=" Back "></A>
|
|
<A HREF="./ayers2.html"><IMG SRC="../gx/fwd.gif" ALT=" Next "></A>
|
|
<P> <hr> <P>
|
|
<!--startcut ==========================================================-->
|
|
</BODY>
|
|
</HTML>
|
|
<!--endcut ============================================================-->
|