From: owner-3dui@hitl.washington.edu on behalf of Doug Bowman
[bowman@vt.edu]
Sent: Wednesday, September 26, 2001 3:12 PM
To: Jian Chen; 3dui List
Subject: RE: Comparison of HMD and Dome

[Just a note to everyone; please remember to reply to the list,
not just to the person who sent the original message]

Jian,

I think this area (comparison of VE displays) is quite crucial.
It's obvious that not all VE displays are created equal, and it's
equally obvious that there is not one "best" display for all
VE applications.

I think that's why Chad was asking about what types of tasks and
applications you would be focusing on.

Let me just clarify what you're asking. I think you're asking
how to compare the two displays in a generic way so that you
can make a purchasing decision. Is that right?

If so, then I think you have to try to generalize the tasks that
users will be performing, similar to my "testbed evaluation" (see
Presence 10(1)). The complex interaction tasks such as 3D selection
and manipulation are likely to show the widest differences between
the displays. Another way to approach the problem is to think about
what outcomes are most important for the users of your system. Is
it task performance time, comfort, level of presence, or something
else?

Some fairly obvious observations:
-The dome requires the user to be seated. This might limit the amount
of natural head/body motion. The HMD can be used standing or seated.

-The dome has a physical screen in space. This might be a problem in
certain 3D selection tasks if the virtual object is behind the screen
and the user is trying to reach for it.

-The dome probably has a much wider field of view.

-The HMD is more portable.

-Setting orientation: the dome lends itself to a vehicle metaphor, where the
user stays stationary and rotates the world, while the HMD lends itself
to a natural/physical turning of the body to orient the viewpoint.

Those are my initial thoughts.

--Doug

--
Doug A. Bowman, Ph.D. (540) 231-2058
Assistant Professor   (540) 231-6075 (fax)
Computer Science      bowman@vt.edu
Virginia Tech       www.cs.vt.edu/~bowman/