Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!psuvax1!swatsun!swatsun!gessel From: gessel@masada.cs.swarthmore.edu (Daniel Mark Gessel) Newsgroups: comp.graphics Subject: Re: checking whether 2 2D polygons overlap Message-ID: Date: 6 Dec 90 17:02:19 GMT References: <111@gem.stack.urc.tue.nl> <18082@netcom.UUCP> <7010@plains.NoDak.edu> <848@portnoy.megatek.uucp> Sender: news@cs.swarthmore.edu Organization: Swarthmore College, Swarthmore Pa. Lines: 25 In-Reply-To: toddh@megatek.UUCP's message of 6 Dec 90 14:15:12 GMT Nntp-Posting-Host: masada In article <848@portnoy.megatek.uucp> toddh@megatek.UUCP (Todd Heckel) writes: >Actually, the Z-buffer is a very brute force technique, one might even say "stupid". >It get's the job done, but it wastes a lot of time dealing with every pixel from >every polygon in the scene, whether or not it will be ultimately visible. It is >also is not compatible with any kind of real-time anti-aliasing technique. The >solution, of course, involves much more complex algorithms which perform various >types of culling operations in order to limit the number of pixels actually rendered. Todd Heckel, net neophyte. Actually, anti-aliasing a zbuffer is easy. But the technique I would use is as brute force and stupid as a z-buffer itself. Render the image into a buffer with twice the resolution in each direction (or more) and have video hardware that averages from 4 pixels (or more). This is probably the most general anti-aliasing technique, and I'd like to see it in things like display postscript and stuff. But it does use 4 (or more) times as much memory and processing power. Dan -- Daniel Mark Gessel Independent Software Consultant Internet: gessel@cs.swarthmore.edu and Developer I do not represent Swarthmore College (thank God). Brought to you by Super Global Mega Corp .com