[sci.virtual-worlds] limiting human DEGREES?

almquist@brahms.udel.edu (Squish) (03/27/91)

Sorry to diverge from Woman in VR :-} BUT, in the process of developing 
a VR platform, I've come across an interesting question.  What are the 
human limiting degrees in vision and hearing?  What's that mean?  What
is our total range of vision? 180 degrees?  What about an individual
_human_ eye?  How much overlap is there between the two eyes?  How
about hearing?  Can each ear hear 360 degrees or does the meat get in
the way?  How much overlap is there between the ears as in the eyes?
I'm trying to figure this out so that information to a rendering system
can be reduced if I only want to render the right eye, etc.  As a
friend stated, "Good software will allow everything or better yet,
should be thought of NOT DISALLOWING ANYTHING!".  I need these values
so that the tests could be run using the senses I'm most familiar with
(mine) before I go onto FLY-like vision (-:  Any info would be greatly
appreciated.  THANKS!

- Mike (almquist@brahms.udel.edu)

straz@media-lab.MEDIA.MIT.EDU (Steve Strassmann) (03/30/91)

   >From: almquist@brahms.udel.edu (Squish)
   >Sender: hlab@milton.u.washington.edu (Human Int. Technology Lab)
   >Organization: *STUCK* at UofD for 3 mo' months

   >a VR platform, I've come across an interesting question.  What are the 
   >human limiting degrees in vision and hearing?  What's that mean?  What
   >is our total range of vision? 180 degrees?  What about an individual
   >_human_ eye?  How much overlap is there between the two eyes?  How
   >about hearing?  Can each ear hear 360 degrees or does the meat get in
   >the way?  How much overlap is there between the ears as in the eyes?

For the answers to all these questions and more, check out
"Humanscale" by Niels Diffrient, Alvin Tilley, and David Harman,
published by MIT Press, Cambridge, Mass.

It comes in several sets of books and nifty plastic rotary spinners
and detailed charts. The sets are available in threes: 1/2/3, 4/5/6,
and 7/8/9.

   1 Sizes of people
   2 Seating considerations
   3 Requirements for handicapped and elderly

   4 Human strength and safety
   5 Hand and foot controls and displays
   6 Head and vision, hands and feet

   7 Standing and sitting at work
   8 Space planning for the individual and public
   9 Access for maintenance, stairs, light, and color

It's incredibly detailed with all sorts of cool facts, tables, and
graphs, like "the human body acts as an antenna and has a resonant
frequency of about 70 megahertz", or a diagram indicating which angles
of rear illumination (approaching from behind your head, over your
ear) are likely to cause distracting reflections for people who wear
eyeglasses. 

Steve Strassmann
MIT Media Lab
straz@media-lab.media.mit.edu

sfp@mars.ornl.gov (Phil Spelt) (04/03/91)

>Subject: limiting human DEGREES?
>Message-ID: <1991Mar30.022253.25376@milton.u.washington.edu>
>Date: 27 Mar 91 01:10:37 GMT
>Sender: hlab@milton.u.washington.edu (Human Int. Technology Lab)
>Organization: *STUCK* at UofD for 3 mo' months

>Sorry to diverge from Woman in VR :-} BUT, in the process of developing 
>a VR platform, I've come across an interesting question.  What are the 
>human limiting degrees in vision and hearing?  What's that mean?  What
>is our total range of vision? 180 degrees? 

That depends on the person -- some of us have wider peripheral vision
than others.  Generally speaking, the monocular field of vision is about
90 - 115 degrees: about 60 degrees to the nasal side of the field, and about 85 
degrees to the ear (outside).  These last are maximum values.  Thus, 85 for
the left eye (to the left ear) plus 85 for the right eye (to the right ear)
gives about 165 degrees MAXIMUM peripheral vision (on the average, without
moving the eyeballs at all).  There is also about a 120 degree (60 degrees on ei
ther side of "dead ahead") for binocular overlap -- where both eyes "see"
the same things.

> What about an individual
>_human_ eye?  How much overlap is there between the two eyes?

I think I answered these questions above.

>How about hearing?  Can each ear hear 360 degrees or does the meat get in
>way?  (something about overlap inadvertently deleated).

Hearing is a different story, as the ear(s) do not have to be "pointed at"j the
source of sound.  Hearing is much less "spatial" than vision -- the sense
of hearing better integrates over time (vision integrates over space).  There is
 a complex wave-form analysis done by the ears in order to localize the source o
f sound.  Thus, when a sound source is  NOT "dead ahead", the sound waves reach
the two ears slightly out-of-phase.  This, plus the slight difference in 
loudness (actually, sound pressure on teh ear drunms) enables us to localize sou
nd spatially.  We are really pretty good at localizing sound this way, given
the fact that humans are primarily visual animals.

>can be reduced if I only want to render the right eye, etc.  As a
>friend stated, "Good software will allow everything or better yet,
>should be thought of NOT DISALLOWING ANYTHING!".  I need these values
>so that the tests could be run using the senses I'm most familiar with
>(mine) before I go onto FLY-like vision (-:  Any info would be greatly
>appreciated.  THANKS!

>- Mike (almquist@brahms.udel.edu)

I would suggest (RECOMMEND) a good text on human perception, followed by one
on human factors, before you get too far into your work.

Hope this helps.

=============================================================================
MIND.  A mysterious form of matter secreted by the brain.  Its chief activity
consists in the endeavor to asscertain its own nature, the futility of the
attempt being due to the fact that it has nothing but itself to know itself
with.   -- Ambrose Bierce
=============================================================================

Phil Spelt, Cognitive Systems & Human Factors Group  sfp@epm.ornl.gov
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Any opinions expressed or implied are my own, IF I choose to own up to them.
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