Newsgroups: sci.virtual-worlds Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!batcomputer!cornell!uw-beaver!milton!hlab From: fenwick@clipper.ingr.com (Stephen Fenwick) Subject: Re: Cheap head-mounted display Message-ID: <1991May15.050816.28757@milton.u.washington.edu> Sender: hlab@milton.u.washington.edu (Human Int. Technology Lab) Organization: Intergraph Advanced Processor Division - Palo Alto, CA References: <1991May10.205155.27367@milton.u.washington.edu> Date: Tue, 14 May 91 16:07:08 GMT Approved: cyberoid@milton.u.washington.edu In article <1991May10.205155.27367@milton.u.washington.edu> cdshaw@cs. ualberta.ca (Chris Shaw) writes: >In article Greg ? writes: >>It seems to me that a powerglove could be used for the position sensor >>(just aim it backwards, and put the receivers behind you) and still >>let you use a power glove for a glove. > >The noisiness of the data given by the ultrasound sensors will drive you wild. >You'll probably have to use a Polhemus Isotrak for head tracking. Your tarring the whole technology with a too-broad brush. Ultrasonics can be used for reliable 2-d and 3-d positioning; I've done it. The project was a derivation of a head-mouse for the Mac (forgot the name) that used three receivers on a headband (one on top, one at each ear, all face forward) and a single transmitter in a base unit placed on top of the Mac. I'm not sure how much I can say about the techniques used (don't recall what non-disclosures were signed at the time), but it was quite possible to get reasonable 3-d positioning (one axis direct, two by translating rotations to translations) based on a single 68HC11, some cheap glue logic, and simple software. Very little filtering (s/w or h/w) was required. Send me e-mail for more details. Steve Fenwick -- Do you seriously think my company would let me speak for it? E-Mail routes: { uunet!ingr! } clipper!fenwick USPS: Intergraph APD, 2400 Geng Road, Palo Alto, California 94303 AT&Tnet: (415) 852-2325