Path: utzoo!mnetor!uunet!husc6!uwvax!oddjob!gargoyle!att-ih!alberta!calgary!blob
From: blob@calgary.UUCP (Brian Wyvill)
Newsgroups: comp.graphics
Subject: Re: Looking for large ( > 1 mega edges) databases
Message-ID: <1444@vaxb.calgary.UUCP>
Date: 10 Mar 88 06:00:35 GMT
References: <235@piring.cwi.nl>
Organization: U. of Calgary, Calgary, Ab.
Lines: 25
Summary: Standard Test Objects

In article <235@piring.cwi.nl>, varol@cwi.nl (Varol Akman) writes:
> I am looking for a large (i.e. more than 1000000 edges) graphics
> object.  I'll use it for non-profit research purposes--to test an
> algorithm.

A lot of people are doing research which involves testing algorithms (such
as ray tracers) with large objects.   I have seen several papers where the
authors use objects of only 4 or 5 thousand polygons.  In practice, scenes
often require hundreds of thousands of polygons and the use of standard
objects would help in comparing algorithms.   Sending test objects of 
this size through the net may not be practical.   One solution is to use
objects which can be generated in a standard fashion.  For example the Menger
sponge  (See Mandelbrot) or the recursive tetrahedrons which have been used by
some researchers (see proc. SIGGRAPH)  Such objects can be
manufactured with a recursive procedure and at different recursion levels
provides discrete numbers of polygons, for example the Menger Sponge
increases by a factor of 20 at every recursion level.
I have a definition of the Menger Sponge written in the graphics language:
PG (Polygon Groper), if there is any interest I will post the program, it may
be of some use even without the PG interpretter.


-- 
        Brian Wyvill
	..!{ubc-vision,ihnp4}!alberta!calgary!blob