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From: kddlab!lkbreth.foretune.co.jp!trebor@uunet.UU.NET (Robert J Woodhead)
Newsgroups: sci.virtual-worlds
Subject: Re: Real-time raytrace -- get serious!
Message-ID: <1991May17.031449.11655@milton.u.washington.edu>
Date: 17 May 91 02:56:45 GMT
References: <1991May15.050715.28438@milton.u.washington.edu> <1991May16.055359.2
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Organization: Foretune Co., Ltd.  Tokyo Japan
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rodent@netcom.COM (Ben Discoe) writes:

>Everyone knows parallel's the way to go.  No, buying 240 expensive
>CPUs isn't the right way - but buying a rack of cheap CPUs is an option
>that i think has some promise.

In the late '70s, I took a computer graphics course by Greenberg at
Cornell University.  For my final paper I designed a distributed
computation real-time 3D hidden-surface rendering system using
multiple 6502-level microprocessors.

The system was a heirarchy of processors.  A toplevel processor
handled communications with the outside world; you could send the
system information like "add or delete a polygon from the database"
and "the current eye orientation is so and so."  The next level
had N processors that rasterized the polygons into "for scan line
Y, start at position X1, depth D1 and go to position X2, depth
D2 in color C."  These were sent through a communications layer
(this made the hardware simpler) to M rendering processors, each
of which handled 1 Mth of a Z-buffer.

The idea was you could be flexible and add/remove cheap processors
to get real-time performance for as complicated a scene as you
were willing to pay for.  It wouldn't be a fancy ray-traced image,
but you'd get as good results as the current VR stuff.

I was seriously pissed when I only got a B on the paper because,
in the words of whoever assigned the grade (maybe a scummy grad
student! grr!), the concept was "totally impractical, impossible
to build, etc."

It was my first lesson in the costs of being ahead of your time.
;^)

-- 
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| Robert J. Woodhead, Biar Games / AnimEigo, Incs.   trebor@foretune.co.jp |
| "The Force. It surrounds us; It enfolds us; It gets us dates on Saturday |
| Nights." -- Obi Wan Kenobi, Famous Jedi Knight and Party Animal.         |