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From: azah@quads.uchicago.edu (ahmed  zahid)
Newsgroups: comp.graphics
Subject: Identifying the coplanar set of vertices.
Message-ID: <1991Jun12.232026.10855@midway.uchicago.edu>
Date: 12 Jun 91 23:20:26 GMT
Sender: news@midway.uchicago.edu (NewsMistress)
Organization: University of Chicago
Lines: 28


I am generating the coordinates of spherical surface by the following
tansformation :

	 x = cos(theta)*sin(phi),
	 y = sin(theta)*sin(phi), and
	 z = cos(phi),

where 0 <= theta <= 360 degrees, and -180 <= phi <= 180 degrees.

Now I am using the IBM R6000 graPHIGS utility GPPGD3 to form the
structure primitive; this function requires that the set of vertices
in the given polygon/sub-area be "coplanar". Consequently I am faced
with the problem of identifying and reorganizing the above set of
coordinates in terms of coplanar sets of vertices. Is there any 
particular approach that I could adopt which would be computationally
efficent ? Any ideas, comments, hints would be appreciated.

_______________________________________________________________________

Zahid Ahmed.

Scientific Visualization Lab,
Center for Clouds, Climate, and Chemistry
University of Chicago.

(312)-702-1808.
ahmed@cassatt.uchicago.edu