Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!ames!haven!uvaarpa!babbage!watt.acc.Virginia.EDU!pts
From: pts@watt.acc.Virginia.EDU (Paul T. Shannon)
Newsgroups: comp.graphics
Subject: Pixar and bicubic Bezier patches
Message-ID: <647@babbage.acc.virginia.edu>
Date: 23 May 89 14:58:45 GMT
Sender: acc@babbage.acc.virginia.edu
Reply-To: pts@watt.acc.Virginia.EDU (Paul T. Shannon)
Organization: Academic Computing Center, University of Va.
Lines: 15

I'm a new Pixar user, new also to 3-d graphics.   It seems that the 
Pixar likes to have solid models described by bicubic Bezier pathches
(though there are other description techniques as well).  From my 
reading, primarily in 'Computer Graphics: Systems and Concepts' by
Salmon and Slater, it looks like the Bezier patch is a means for economically
describing a surface, but that it is not a precise description.  

In the 2-d case, a Bezier curve only provides control points, and the
resulting curve can be quite different.  Is the same thing true of the
3-d control graph?

My first project requires me to create very simple shapes, specifically
a transparent sphere with opaque polygons and circles on the sphere's
surface.  Are bicubic bezier patches a good way to create surfaces and
solids of precise shape and dimension?