Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!ginosko!uunet!cbmvax!mitchell
From: mitchell@cbmvax.UUCP (Fred Mitchell - QA)
Newsgroups: comp.graphics
Subject: Re: Intersection between a line and a polygon (UNDECIDABLE??)
Keywords: P, NP, Jordan curve separation, Ursyhon Metrization Theorem
Message-ID: <8058@cbmvax.UUCP>
Date: 2 Oct 89 22:50:50 GMT
References: <2972@ndsuvax.UUCP> <32610@cornell.UUCP>
Reply-To: mitchell@cbmvax.UUCP (Fred Mitchell - QA)
Organization: Commodore Technology, West Chester, PA
Lines: 10

A simpler way of thinking about it is to:
	1) compute the plane the polygon lies in
	2) calculate the point where line intersects plane
	3) determine if point lies inside or outside of polygon.

A possible way of determining 3) would be to do a bounding box
around polygon and if point lies outside bounding box, you know
that its outside. If in, you've more checking to do. Since I have
done this in the Ray-Trace package I'm currently working on,
drop me E-mail if you want more details.