Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!asuvax!ncar!gatech!usenet.ins.cwru.edu!eagle!data.nas.nasa.gov!wilbur.nas.nasa.gov!eugene
From: eugene@nas.nasa.gov (Eugene N. Miya)
Newsgroups: comp.graphics
Subject: Re: Viewer-Centered Graphics (nee Psycho-, nee Subjective-,nee Turing Test)
Keywords: perception, perspective, Leonardo, realism, physics
Message-ID: <1991Mar6.220940.8400@nas.nasa.gov>
Date: 6 Mar 91 22:09:40 GMT
References: <91Feb20.131305est.6899@neat.cs.toronto.edu> <heffron.667761078@falstaff.css.beckman.com> <3118@charon.cwi.nl>
Sender: news@nas.nasa.gov
Reply-To: eugene@wilbur.nas.nasa.gov (Eugene N. Miya)
Organization: NAS Program, NASA Ames Research Center, Moffett Field, CA
Lines: 24

On a long drive back from the Sierra, I pondered this topic more.
Perspective does have uses.  This is how we make maps, topographic maps,
and other maps.  Is there any image more pervasive and full of more
useful information than a map?  I don't think so.

The perspective of two images creates a radial displacement
(photogrammetry term) which our brains fuse together to comprehend
depth.  We pick up other cues (e.g., over lap, time and age).
People spend hours pouring over images like these to create topo maps.

And look what we get from them: a little model of the world in orthogonal,
synopic view (these big words from my remote sensing classes).  You can
adding the distances, figure out how long the drive tapes, the symbols
in the legend can convey non-geometric information.  Most photographs or
synthetic images can't approach the information content of a good map.
With a computer and a good map, one could determine the volume of material
ejected by Mt. St. Helens.  It's the quality of the model which is important.

	"Welcome Mr. Beatty to the Parallax Corporation."
			-- The Parallax View

--e. nobuo utsunomiya, NASA Ames Research Center, eugene@orville.nas.nasa.gov
  {uunet,mailrus,other gateways}!ames!eugene
  AMERICA: CHANGE IT OR LOSE IT.