From: orourke@grendel.csc.smith.edu (Joseph O'Rourke)
Newsgroups: comp.graphics.algorithms
Subject: Re: Polygon Centroid
Date: 20 Feb 1996 02:10:18 GMT

In article <AD4E041A966890AD@slip-d4.rdrop.com>,
David A. Cary <d.cary@ieee.org> wrote:
>
>If the polygon you have is perfectly planar, you should be able to take the
>Graphics Gems algorithm and simply substitute 3D vectors rather than 2D
>vectors.
>
Perhaps not, but in any case, you could project the polygon to one
of the three planes determined by the coordinate axes, then run the
2D algorithm to find a point Q, then project Q back to the plane of
your polygon to get a point P, the centroid.

PS. 2D centroid code is reachable from http://cs.smith.edu/~orourke.