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From: msr@gator.cacs.usl.edu (Srinivas R. Manapragada)
Newsgroups: comp.graphics
Subject: Re: Scene Description Standard
Message-ID: <30137@rouge.usl.edu>
Date: 30 Apr 91 05:56:25 GMT
References: <1991Apr30.003612.16050@mks.com>
Sender: anon@rouge.usl.edu
Organization: The Center for Advanced Computer Studies, USL
Lines: 31

In article <1991Apr30.003612.16050@mks.com> david@mks.com (David Rowley) writes:
>One of the harder problems in producing snazzy computer graphics seems
>to be the modelling, rather than the rendering.  One reason for this is
>the lack of a standard modelling format.
>
>Would it make sense to define a new, say text-based, format to describe
>a world, such that a renderer could use as much information from it
>as possible, and chuck the rest ?
> ...
>Does it make sense ?  Anyone interested ?

Yes it would be nice to have a standard. However it should be more expressive
and powerful than the language of say rayshade, which allows hierarchical
objects to be defined rather easily. However one should also have some kind of
procedural features. For example say while describing a forest I should be able
to define it as

	for(x = 0; x < 100; x++)
	    for(y = 0; y < 100; y++)
		FirTree(x + dither(), y + dither());
	
	where FirTree is the parameterized object and dither provides a small
amount of +- deviation. Ofcourse the object need not have its position as a
parameter since they may be more naturally handled by modelling transformations
but it may be more important to parameterize by, say, the surface color, texture
etc.

Also very compact descriptions arise through the use of fractals, IFS's etc., I
wonder if they can be pulled into the language.

_Srini_