From: Anders Backman [andersb@cs.umu.se]
Sent: Tuesday, August 17, 1999 8:02 AM
To: 3d-ui@hitl.washington.edu
Subject: Basic HMD question

Hi everybody.
I have a very basic HMD question.

I guess you all have experienced the problem with translation during
rotation using a tracker mounted on a HMD.

The problem arise when the tracker is mounted a bit from the eyes, on top,
on the side or on the back of the head.

I wonder if you have a simple solution for compensating this?
I have read the Viewing model for virtual environment displays by David A.
Southard.

But it didnt give me the practical stuff I need. (some code perhaps would
help?)


Also another problem (could be due to the above one).
It seems that humans are much more sensitive to tilting then for example
panning.

We have tested this on some persons.

A normal rotation or a elevation change (people shaking/nodding) doesnt
affect them so much.
But when they lay their head on the side (tilt) they report a strange
sensation.

Doing this in the real world, just gives you the feeling of your head being
tilted.
But in a HMD its like the world is tilting and you are standing straight.


Due to lag, wrong calibration, ...?

Comments on this too?


________________________________________________________________
 Anders Backman               Email:    andersb@cs.umu.se
 HPC2N/CUT                    Phone:    +46 (0)90-786 9936
 Umea university              Cellular: +46 (0)70-392 64 67
 S-901 87 UMEA SWEDEN         Fax:      +46 90-786 6126
                              http://www.cs.umu.se/~andersb