Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!snorkelwacker!bloom-beacon!eru!luth!sunic!nuug!ulrik!ulrik!tevfik From: tevfik@ulrik.uio.no (Tevfik Karagulle) Newsgroups: comp.graphics Subject: Re: AREA MEASUREMENT OUT OF POLYGON-CONTOUR DATA Message-ID: Date: 10 Aug 90 08:31:38 GMT References: Sender: tevfik@ulrik.uio.no (Tevfik Karagulle) Distribution: comp.graphics Organization: Anatomical Institute, University of Oslo, Norway Lines: 24 In-Reply-To: tevfik@ulrik.uio.no's message of 10 Aug 90 10:11:51 NB! There is a mistake in my previous posting. Please read this one : From 'Foley, Van Dam : Fundamentals of Interactive Computer Graphics, 1982, p.513' : For instance, the area C of the polygon projected onto xy plane is just n ---- 1 \ C = - \ (y + y ) (x + x) 2 / i i@1 i ^ i@1 / | ---- | i=1 NB! THIS MUST BE - (minus). where the operator @ is normal addition except that n@1 = 1. Regards, Tevfik Karagulle, UiO, Norway (Internet : tevfik%vision01@ifi.uio.no)