Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!samsung!uunet!seas.gwu.edu!gritz
From: gritz@seas.gwu.edu (Larry Gritz)
Newsgroups: comp.graphics
Subject: Re: Scene Description Standard (Renderman isn't good enough)
Message-ID: <3144@sparko.gwu.edu>
Date: 1 May 91 20:11:04 GMT
References: <1991Apr30.211131.7166@nntp-server.caltech.edu>
Reply-To: gritz@seas.gwu.edu (Larry Gritz)
Organization: The George Washington University, Washington D.C.
Lines: 42

In article <1991Apr30.211131.7166@nntp-server.caltech.edu> woolstar@nntp-server.caltech.edu (John D. Woolverton) writes:
>
>   I would love to have a standard interface to work with
>(from both sides: modeling and rendering).  However my investigation
>of RenderMan has been _very_ dissapointing.
>
>   Perhapse to the world of 3D Z-buffers and other scan line
>rendering programs, RenderMan is enough.  But for work in
>RayTracing and beyond, there are too many things missing.
>

Not only is RenderMan perfectly acceptable for describing scenes to a
renderer which uses ray tracing, but RenderMan supports features which
are not possible on ray tracers at all (e.g. Displacement shaders).
I wonder exactly which features you want that cannot be described in
RenderMan?  Don't forget the explicit "trace" command in the shading language.


>   Renderman is also grossly inefficient for representing
>polygons, as it takes a [vertex, vertex, vertex, close] form for
>representing each face instead of a list of verteces and then a
>face list.

Not true at all.  See RiPointsPolygons and RiGeneralPointsPolygons.


>   Finally the concept of an actor/object is non-existant
>in RenderMan.  

This is because RenderMan is designed to be an interface to a renderer,
not a way to specify models or animation scripts.


>
>	John D. Woolverton, Video Bits
>	woolstar@cobalt.caltech.edu

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Larry Gritz                                     lg@galileo.usno.navy.mil
US Naval Observatory                            202-653-1034
Washington, DC 20392-5100                       also: gritz@seas.gwu.edu
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