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From: billd@fps.com (Bill Davidson)
Newsgroups: comp.graphics
Subject: Re: PoolTable Turing Test Photo
Message-ID: <15115@celit.fps.com>
Date: 26 Jan 91 02:28:28 GMT
References: <7926@castle.ed.ac.uk> <28220@cs.yale.edu> <1991Jan25.142659.3914@jarvis.csri.toronto.edu>
Organization: FPS Computing Inc., San Diego CA
Lines: 35

In article <1991Jan25.142659.3914@jarvis.csri.toronto.edu> stam@dgp.toronto.edu (Jos Stam) writes:
>I wouldn't mind seeing more dirt in computer generated images, just for
>the sake of variety. By analogy, figurative art is not only restricted to 
>hyperrealism.

The pool table picture was an attempt at photo-realism; something we
are getting closer to but can't quite do.  It was an extremely good
example (especially for 1984) though it attacked something that was
relatively easy (spheres and green felt).  I think the real emphasis
was coming up with a good model for motion blur (it made my jaw drop
when I first saw it).  It almost looks like a real photograph with
strobes.  There are two major clues: the lack of imperfection and the
lack of camera lens reflection in the balls.  In many professionaly
produced pictures of shiny spherical objects, the camera lens is
retouched out or obscured by other reflections around it (you can't
shoot it without the reflection; it's impossible).  If you were really
trying to fool the viewer (given that that is a goal) you might even
put in a camera lens reflection.

More generally, lighting models are getting really good; to the point
that objects look as if they could be real, even though in all cases
you know they aren't (I have yet to see a computer generated image that
I couldn't tell was not a photograph of a real scene though some took a
few seconds of looking).  Of course we could debate how important
photorealism really is.  While in general, I don't need it or really
care, it would be nice to know that you could do it if you wanted to.
As far as being for variety, it seems like an awful lot of work for
mere variety.  You'll get more pleasing variety from creative artists
using computer graphics than from a small technical improvment (gained
at great expense).  This is not to say that I am against increased
photorealism but "variety" just seems like a dumb reason.  Increasing
the state of the art and available tools for artists and scientists is
a better reason.

--Bill Davidson