Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!mit-eddie!uw-beaver!ubc-vision!fornax!chapman
From: chapman@fornax.uucp (John Chapman)
Newsgroups: comp.graphics
Subject: Re: ray tracing (Was Amiga ray tracer)
Message-ID: <275@fornax.uucp>
Date: Sat, 2-May-87 15:48:20 EDT
Article-I.D.: fornax.275
Posted: Sat May  2 15:48:20 1987
Date-Received: Wed, 6-May-87 04:48:16 EDT
References: <1514@sphinx.uchicago.edu> <4947@hi.uucp> <829@bgsuvax.UUCP> <21416@styx.UUCP> <824@osu-cgrg.UUCP>
Organization: School of Computing Science, SFU, Burnaby, B.C. Canada
Lines: 35

> In article <21416@styx.UUCP>, carlson@styx.UUCP (John Carlson) writes:
> > In article <823@osu-cgrg.UUCP> spencer@osu-cgrg.UUCP (Steve Spencer) writes:
> > >Basically, it falls into these categories:
> > > 1.  a hierarchical subdivision scheme, usually an octree-like approach.
> > >     this is quicker than...
> > > 2.  an equal-sized spatial subdivision (break the "world" into NxNxN
> > >      equal sized boxes.  
> > >     this method is easier to implement then #1, but it is slower.
> > 
> > This is news to me (and I am trying to catch up). 
> > Do you have empirical or experimental data to show this? 
> 
> Not that I have actual numbers right here with me, but I seem to remember
> a slightly quicker runtime for octree-based subdivision versus the SEADS
> (equal-sized subdivision) method.  Intuitively, it would make sense that

Fujimoto et al claim SEADS with 3DDDA is faster than octrees, at least
in part because of the simplicity of cell-to-cell moves in 3DDDA compared
to octrees. They claim an order of magnitude improvement in time over
octrees. The paper is in the April 86 issue of CG&A.
In computing intuition can get you into hot water :-).

.
.
. 
> Stephen Spencer, Graduate Student
> The Computer Graphics Research Group
> The Ohio State University
> 1501 Neil Avenue, Columbus OH 43210
> {decvax,ucbvax}!cbosg!osu-cgrg!spencer        (uucp)

*** REPLACE THIS LINE WITH YOUR MESSAGE ***
-- 
{watmath,seismo,uw-beaver}!ubc-vision!fornax!sfulccr!chapman
                   or  ...!ubc-vision!sfucmpt!chapman