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From: cdshaw@cs.ualberta.ca (Chris Shaw)
Newsgroups: sci.virtual-worlds
Subject: Re: Cheap head-mounted display
Message-ID: <1991May16.055148.2358@milton.u.washington.edu>
Date: 15 May 91 06:24:00 GMT
References: <1991May10.205155.27367@milton.u.washington.edu>
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Organization: University of Alberta, Edmonton, Canada
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Steve Fenwick :

>In article cdshaw@cs.ualberta.ca (Chris Shaw) writes:
>>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.
>
>You're 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.
>Steve Fenwick

Perhaps I am, perhaps not.

The original post in this thread suggested that the Power Glove ultrasonic
trackers be used for head tracking. This means that you need to track
position and orientation, at all attitudes (no dead spots). For head tracking,
the data should also be low noise, else the jitter will "drive you nuts".
Ultrasonics are probably ideal for position-only tracking, but currently the
powerglove will give only roll-of-forearm data, and will only work when 
your arm is facing the sensor array. Of course, you COULD use this to detect
head-turn +/- 90 degrees, but that's all. No looking up or down with this 
setup. 

Ultrasound is certainly worth looking into, though, because it's got a 
big price advantage.
-- 
Chris Shaw     University of Alberta
cdshaw@cs.UAlberta.ca           Now with new, minty Internet flavour!
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