From: stone@kobra.usc.edu (Chris Stone)
Subject: TECH: VPL Polhemus Sensor
Date: 11 Jun 1992 13:38:29 -0700
Message-ID: <l3fee5INNcp5@kobra.usc.edu>
Organization: University of Southern California, Los Angeles, CA



Hi everyone, I am fairly new to this news group so I don't know
if this discussion has come up before. Anyway, I am working with
VPL's dataglove (model III, I think) and my question has to
do with the polhemus sensor. For some reason the polhemus
sensor does not have negative z-values, and to the best of my
knowledge there is no way to distinguish which side of the
z=0 plane your hand is on.  I also noticed that when the
glove is behind (z < 0) the sensor that the x and y values
get reversed (that is, the positives go to negatives and vice
versa). Why is it set up in this way?? And is there any way
to be *completely* sure whether or not the glove is in
front or in back of the sensor (without adding a second
additional sensor)??? I hope that there is some logical reason
why the polhemus sensor works in this way, and if there is
I would certainly like to know it. Thanks for you help.

-chris