Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!ncar!noao!asuvax!mcdphx!mcdchg!ddsw1!corpane!sparks
From: sparks@corpane.UUCP (John Sparks)
Newsgroups: comp.graphics
Subject: Re: Ray Trace for IBM
Summary: some ray tracing bench marks
Message-ID: <340@corpane.UUCP>
Date: 15 Feb 89 15:28:46 GMT
References: <986@novavax.UUCP> <2897@m2-net.UUCP>
Organization: Corpane Industries, Inc., Louisville Ky
Lines: 49

In article <2897@m2-net.UUCP>, sa@m-net.UUCP (Scott A. Almburg) writes:
> 
> Doesn;t  ray  tracing take up huge amounts of cpu time?  Does anyone
> have examples  of  cpu time/ frame on various machines?
> I would think  several hundred hours per frame on an ibm might not
> be too far off...

not quite that high. I have an Amiga 1000 (running a 68010) and regularly
use a program called DBW-Render, I ported this program over to a microvax
and a compaq 386-20 (20mhz) with 387 math co-processor

 Here are the times to calculate the same picture
on the various machines. The picture was a translucent pyramid with a mirror
sphere in the pyramid. the pyramid sat on a plane with circular waves eminating
from the pyramid (like water with a stone thrown in it).

Amiga......................12 hours
MicroVax....................1 hour
Compaq.....................40 minutes

note: the vax had about 3 other users on it at the time and the compaq was 
running microport unix and (besides the usual background tasks) the raytracer
was the only program running.

in DBW-render you can specify how long you wish to calculate. It is just a
rough estimate. If you specify a low number you get a fuzzy picture. good
for quick checks. the time was set for 18 hours in the above tests. this
created a complete picture. any more time specified would have still taken
the same amount of time to calculate.

I figure the compaq did so nice because of the math co-processor and the hard
disk (dbw-render writes the scan lines to disk as it calculates them)
My Amiga has no co-processor and only a floppy.


There is another program called QRT (Quick Ray Tracer) for the amiga (and
I read in a previous article, also for the IBM now) that is very fast.

on the amiga it will calculate a picture in less than an hour. I never could
get it to work on the vax or the compaq. but I will get the ibm version and
try that one soon.

---

John Sparks      // Amiga  |  {rutgers|uunet}!ukma!corpane!sparks 
               \X/  UUCP   |  >> call D.I.S.K. @ 502/968-5401 thru 5406 << 
 
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