From: dstamp@watserv1.waterloo.edu (Dave Stampe-Psy+Eng)
Subject: Re: Viewing 3D images in a Head Mounted Display
Date: Tue, 14 Jan 1992 22:00:21 GMT
Message-ID: <1992Jan14.220021.4925@watserv1.waterloo.edu>
Organization: University of Waterloo



cs_d476@ux.kingston.ac.uk (pete leaback) writes:

>While using W Industries "Virtuality" head mounted display, I found
>it hard to fuse the two projected views of an object into one 3D object.
>
>I presume what was happening was that my eyes were refusing to go 
>cross-eyed enough to bring the object into true.
>
>Is this a common problem ? What stimulus does the eye/brain need to
>re-adjust the amount of cross-eyedness ? 

This is a common problem with all stereoscopic viewing stuff.  With
VR, you usually have a greater depth of view, so it's worse.  In
thery, blurry images should not increase the eyestrain, just lower
the depth resolution.

What really hurts is when the focal depth is different from the 
stereo (convergence) depth.  Most people can tolerate a certain
amount of disparity here, but 20% of the population cannot view
stereoscopic pictures properly anyway!

I suspect that part of the problem is that the Virtuality gear has no
way to adjust to different eye spacings.  If the optics are not built
to conpensate for this, image displacement will occur when the user's
interocular distance is different from the design distance.  So this
can exacerbate the problem.

I think that all VR systems should have a way to adjust this in software.
Also, there should be ways to compensate for display centering and
errors in magnification caused by nonideal fit.  Makes sense, but you
need a bit more setup time.

--------------------------------------------------------------------------
| My life is Hardware,                    |                              | 
| my destiny is Software,                 |         Dave Stampe          |
| my CPU is Wetware...                    |                              | 
| Anybody got a SDB I can borrow?         | dstamp@watserv1.uwaterloo.ca |
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