From: scivw@hitl.washington.edu
Subject: DIGEST: Virtual-worlds Info Booth [04.33]
Date: December 31, 1996
Organization: Human Interface Technology Laboratory, U of Washington, Seattle



Virtual-worlds Info Booth Digest
volume 04, number 33

Contents:
INFO: VR Video
INFO: Virtual Reality Headsets/Tracking

See the Sci.Virtual-Worlds FAQ, posted monthly
http://www.hitl.washington.edu/projects/knowledge_base/virtual-worlds/readfirst-faq.html,
for more details on the organization of this newsgroup.  There is also
a home page for the ftp site: URL:

	     ftp://ftp.hitl.washington.edu/pub/scivw/WWW/scivw.html

This Digest is archived at the sci.virtual-worlds archive site, URL:

	        ftp://ftp.hitl.washington.edu/pub/scivw/Digests/

Toni Emerson                                         
Moderator, sci.virtual-worlds               

                      <scivw-request@hitl.washington.edu>
                http://www.hitl.washington.edu/people/diderot

---------------------------------START OF DIGEST------------------------------ 

From: Alain Grumbach <grumbach@inf.enst.fr>
Date: Tue, 24 Dec 1996 16:08:56 +0100 (MET)
Message-Id: <199612241508.QAA07716@golicha.enst.fr>
Newsgroups: sci.virtual-worlds
Subject: INFO: VR Video

Dear Sir,

I am creating a new course on VR for French students.
Video is a good way to interest them, and to illustrate VR.
Do you know some videos showing VR realizations,
which could be used for such a purpose (free or not) ?

Thanks.

             iii Merry virtual Xmas iii

                             *** Happy new real year ***


Alain Grumbach


---------------------------------------

From: Anthony Breckner <abreck@globalnet.co.uk>
Newsgroups: sci.virtual-worlds
Subject: INFO: Virtual Reality Headsets/Tracking
Date: Tue, 24 Dec 1996 00:01:41 +0000
Message-Id: <32BF1D65.7FB1@globalnet.co.uk>


Does anybody know how a VR headset can tell the position and direction 
of the user's head? I have a sneaking suspicion that magnetic fields are 
involved. If you do know, could you just email me a basic idea of how it 
works (ie the basic concept)?
Cheers
Anthony Breckner


[Head tracking is done with position/orientation sensors.
These tracking devices can be electromagnetic, ultrasonic, mechanical,
inertial, or optical.

There are two (unfortunately, old) review article on trackers:

Meyer, K., Applewhite, H.L. and Biocca, F. A. (1992). A Survey of
Position Trackers.  Presence, 1(2), pp.
173-200.

Abstract

This paper is a survey of position-tracking technologies and their use
in virtual reality (VR) applications. A framework is established to
evaluate the suitability of a position-tracking implementation for
virtual reality use.  Mechanical, optical, magnetic, and acoustic
implementations are discussed with examples of each. Also, the effect
of position tracking on a virtual reality user is discussed,
especially with regard to the position tracker's role as a cause of
simulation sickness. A catalog of implementations and uses is included
in an appendix.

Bhatnagar,D.K. (1993) Position Trackers for Head Mounted Displays: A
Survey.  UNC technical Report TR93-010.  Available at the UNC WWW
site:

http://www.cs.unc.edu/Research/tech-reports.html

Partial Tracker List:

Intersense - InterGlide inertial tracking system:

http://www.isense.com

Ascension Technology

http://www.ascension-tech.com/

Polhemus - FastTrak

http://www.polhemus.com

General Reality - CyberTrack-II

http://www.genreality.com/

-T.E.]

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