Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ames!uakari.primate.wisc.edu!aplcen!ginosko!uunet!mcsun!cernvax!unizh!wuethri From: wuethri@unizh.UUCP (Charles Wuethrich) Newsgroups: comp.graphics Subject: Re: Hexagonal Pixels Message-ID: <307@unizh.UUCP> Date: 15 Sep 89 14:21:35 GMT References: <2477@canisius.UUCP> <17400010@hpfcdj.HP.COM> Sender: Reply-To: wuethri@gorgo.UUCP (Charles Wuethrich) Organization: Inst. fuer Informatik, Univ. Zuerich, Switzerland Lines: 57 To: unizh!cernvax!mcsun!uunet!ginosko!usc!rutgers!tut.cis.ohio-state.edu!ucbvax!hplabs!hpfcso!hpfcdj!myers Subject: Re: Hexagonal Pixels Newsgroups: comp.graphics In-Reply-To: <17400010@hpfcdj.HP.COM> References: <2477@canisius.UUCP> Organization: University of Zurich, Dept. of Computer Science Cc: mckee@canisius.edu Bcc: myers%hpfcla@hplabs.hp.com In article <17400010@hpfcdj.HP.COM> myers@hpfcdj.UUCP writes: >>Just today I was discussing with a professor of mine about the use of >>hexagonal pixels. Someone that I had talked to at Siggraph this year >>was telling me about how "in France there are monitors which use >>hexagonal pixels", yet my prof still believes that if a hexagonal >>tessalation is used, it is most likely converted into rectangular >>pixels. Could anyone point me into the right direction on this >>subject? > >As far as the *monitor* is concerned, "hexagonal pixel" (or rectangular, for >that matter) is a meaningless phrase. All the monitor knows is that the >beam(s) in the CRT was turned on for X amount of time, during this particular >scan line. The rise/fall times of the video amplifier, plus the shape of the >beam itself (ignoring other shape-distoring items like geometry correction >magnets) determines the shape of the spot. The electron beam itself is most >often viewed as having a Gaussian cross-section; the best you can do, then >as far as actual pixel shape in concerned is a circular spot (which actually >falls off from the center in Gaussian manner along both axes). In reality, >the limits of rise and fall times tend to distort this slightly, which is why >single-pixel-wide vertical lines tend to be dimmer than single horizontal >lines, unless your display system is smart enough to "stretch" single pixels. The issue is right, but......... You are forgetting about LCD screen displays. There is the factual possibility of building a screen based on hexagonal pixels......... with hexagonal (really Hexagonal) pixels. On the other hand, even on a CRT with slight modifications you could build a screen with "circular" pixels, the centers of which lie as the centers of a set of hexagons, all adjacent to each other and all equal, which covers the plane. In this case the pixels are indeed circular but..... They lie on a hexagonal grid...... (very easy thing to achieve this one). >array of dots. (Unless there's somebody out there designing a REALLY funky >frame buffer! :-)) This is an interesting one though, I am working on this subject since 3 years and the buffer isn't too much complicated... you can still use Cartesian coordinates, though you'll need to choose them non-orthogonal. Drop me a note if you are interested........ > > >Bob Myers KC0EW HP Graphics Tech. Div.| Opinions expressed here are not > Ft. Collins, Colorado | those of my employer or any other >myers%hpfcla@hplabs.hp.com | sentient life-form on this planet. Charles Wuethrich, Dept. of Computer Sciences | wuethri@ifi.unizh.ch Univ. of Zurich, 8057 Zurich-Irchel, Switzerland | k114910@czhrzu1a.bitnet