From: thinman@netcom.com (Lance Norskog)
Subject: TECH: Sci Am 5-92 and HMD's
Date: Mon, 18 May 92 09:34:43 PDT


The Scientific American of May 1992 contains two back-to-back
articles which are important reading for any HMD designer.

The first article is a "Science In Pictures (TM)" sort of
interactive science demonstration of interesting blind spot
effects.  Example: a wheel has spokes between inner & outer
circles.  If the inner circle is in your blind spot, you
"fill in" the spokes to the center of the missing circle.

The second article details a new kind of mirror made via
semiconductor etching techniques.  You custom-design a
field of diffraction gratings instead of shaping a smooth
curved shiny surface.  Apparently it doesn't have the
restrictions that mirror optics has, and it can do a
lot of things that you can't with mirrors.  

The first is important for helping to figure new tricks
that you can get away with; or if only to remind you that
visual perception is very complex.  The second is important
if you're designing HMD's with monitors hanging off the side
and reflected via mirrors in front of the eye.  It's quite
possible that you could composite the images seen by each eye
from an invariant background from one monitor and per-eye
views from another monitor...