Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!ogicse!milton!cdshaw@cs.ualberta.ca From: cdshaw@cs.ualberta.ca (Chris Shaw) Newsgroups: sci.virtual-worlds Subject: Re: Polhemous tracking devices Keywords: Flying Mouse, Ascension Technologies, I/O devices Message-ID: <8369@milton.u.washington.edu> Date: 27 Sep 90 08:49:28 GMT Sender: cyberoid@milton.u.washington.edu Organization: University of Alberta, Edmonton, Canada Lines: 76 Approved: hitl@hardy.u.washington.edu >In article jorice@maths.tcd.ie (Jonathan Rice) writes: >>*DC* field. >> The Bird (TM) 6D graphics input device The Bird uses a continuous version of electromagnetic sensing (what someone refers to as DC field), whereas the Polhemus uses some sort of pulsed sensing. I don't know the electronic details. >I was told at SIGGRAPH that The Bird also uses a Polhemus sensor. No. The Bird uses Ascencion's "own" sensor technology. >other hand, the blurb I've got in front of me touts it as "the only 6D >input system that works...near metal and other obstructions," True. However, when I used it, it seemed to me that the cable was artificially too short, and that the effective range of the Bird was about 2.5 feet, less than Polhemus' 4-5 feet. Also, either the demo program introduced lots of lag or the Bird was heavily lagged. Either way, I think that the Bird's metal immunity is bought at the expense of limited range and slow response time. >(maybe Polhemus makes both, now?) No. Although there's a legal battle underway. The president of Ascension is an ex Polhemus employee. You can guess the stolen technology arguments. >Also, the $5000 price tag is the single-unit price. 2-4 units saves 20%, > 75-99 saves >55%, >99 "consult Ascension." The Ascension guy's dreaming. He's got to get his software up to snuff first. Anyway, do you plan on buying more than 4? >>There's also this similar device called the Flying Mouse (TM): > >In my (humble) opinion, one big difference between these two devices is >ergonomic. Both are standard mouses on the ground, and 6D mouses in the >air. (I'm pretty sure) both have RS-232 interfaces. The Flying Mouse is a >largish thing, about like a DECStation mouse with wings that fit nicely under >the thumb and pinky, while The Bird is a tiny thing that made my hand cramp >just looking at it. I thought that the mouse sizes were about equal, but the SimGraphics thing was better because it fit the right hand better (or worse, if you're left handed). >Notice how everything using the Polhemus sensor has a pretty hefty price >tag on it? My guess is that nobody gets the sensors for less than $1K or so. >I'd like to know the single-unit price on it if anyone happens to know. Basic Polhemus Isotrak is $3000. That's one source & one sensor. If you're going to use more than one sensor, get one of the multi-sensor single source models. It's a lot more convenient, and you have only one reference frame instead of N for N sensors. >SimGraphics had an engineering proto of a Flying Mouse with a hacked-up >tactile sensing. Next year, maybe. Interesting, interesting... Actually, it was another company who was doing the Flying Mouse hack with Sim Graphics' help. Anyway, I think that SimGraphics' software is a whole lot better than what Ascension is offering. Ascension is offering some doofus serial line driver software for PC's I think (like Polhemus with Isotraks), while SimGraphics has integrated its Flying Mouse into the Iris GL Graphics Library, and other machines also, I'm told. You can get Flying Mouse events in the GL event queue if you want. That alone (i.e. painless system integration with no kernel hacks) is almost worth the price of admission. >John R. Murray | "They call me Mr. Know-it-all, I am so eloquent. -- Chris Shaw University of Alberta cdshaw@cs.UAlberta.ca Now with new, minty Internet flavour! CatchPhrase: Bogus as HELL !