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From: u-jmolse%sunset.utah.edu@utah-gr.UUCP (John M. Olsen)
Newsgroups: rec.arts.startrek,comp.graphics
Subject: Re: Star Trek II graphics: "The Genesis Effect"
Keywords: star trek graphics genesis
Message-ID: <2908@utah-gr.UUCP>
Date: 10 Oct 88 03:39:21 GMT
References: <277@pte.UUCP> <523@epicb.UUCP> <12672@oberon.USC.EDU> <1486@viper.Lynx.MN.Org>
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Reply-To: u-jmolse%sunset.utah.edu.UUCP@utah-gr.UUCP (John M. Olsen)
Organization: University of Utah, Computer Science Dept.
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dave@viper.Lynx.MN.Org (David Messer) writes:
<ahoffman@skat.usc.edu (Alan M. Hoffman) writes:
< >An interesting sidebar to the "Genesis Effect" article is that all of those
< >funky "particle" sequences--the random "flames" and the wave effect--were
< >generated using fractical math.

<Sorry, they were generated with a "particle system".  This has
<nothing to do with fractals other than the fact that both use
<random numbers and can be used for "data-base enhancement."
<[...]
<Copyright 1988 David Messer -- All Rights Reserved
<This work may be freely copied.  Any restrictions on
<redistribution of this work are prohibited.

Well, if you define the life cycle of your particles recursively, then it
could easily be classified as fractal.  I don't think this is the case with
the Genesis Effect, however.  As a simple example, a particle can evolve
into two similar child particles, which would work nicely for certain types
of dynamic systems like flames and explosions, or static systems like plant
branches.  You just need to limit the number of generations to prevent
pangalactic-sized particle systems. :^)  Particle systems also usually
rely heavily on random number generators, so most particle system fractals
would tend to be random most of the time, like branches of a fruit tree
instead of things like fern leaves.

But I would have to agree with Dave that the Genesis Effect doesn't look
like a fractal system.  Neither is "white sand", a particle system picture
of some desert grass that is on the cover of Geometric Modeling, by Michael
E Mortenson.  I don't know where the picture came from originally.

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