From: rwzobel@unity.ncsu.edu (Rick Zobel)
Newsgroups: sci.virtual-worlds
Subject: SCI: More Vr and Psychology
Date: 13 Nov 92 16:58:54 GMT
Article-I.D.: u.1992Nov14.011705.12007
Organization: North Carolina State University Computing Center
Originator: hlab@stein.u.washington.edu


I am currently working on my Masters thesis (in architecture), which
deals with the representation of the experiential qualities of
architecture, and have had some interesting findings which relate
to this psychology thread.

I have modelled a building which already exists here in Raleigh, NC
and put it into the immersion equipment at UNC's graphics lab. (My
point was not to do a direct comparison, but rather to use this as
a "control" model off which another model could be tested.) I had
a friend who had never seen the building before come with me and 
he walked through the "virtual" building for about half an hour. We 
then happened to have the time to go see the actual building, and 
found some interesting things relating to his perception of the
space in VR versus in reality. Comments similar to these have been
echoed by others who have toured the virtual building. Following
is a brief compilation of these discussions, as well as some
random thoughts which relate:

Flying:  The ability to fly around the space rather than walking,
distorts the perception of size and scale. Spaces separated
vertically (balconies, other floors, clearstory windows) are
no longer perceived as separate due to the ability to move vertically
as easily as horizontally. Also, the ability to fly through or
over walls/doors/windows and other space containing elements
gives the feeling that the building is no longer "solid". 
Wayfinding takes on a whole new meaning, with direct paths from
point A to point B taken through walls, floors or anything else
to aid in the immediacy of getting there. Due to this style of
movement, I find myself frequently repeating interesting phrases
such as "You are inside the wall"; "Fly down, you are in the
roof"; "Look around, your world is out there somewhere"; "look
straight up, you have flown through the floor the ground and are 
currently under everything"; and "Your head is just barely sticking 
through the floor." Interestingly enough, the one thing you 
really don't need in VR, a stairway, is the favorite test area 
for honing flying skills. 

Combinations of virtual and physical movement I have found is
difficult for people to use logically. The magnetic tracker allows
for a reasonably large degree of movement (about a 6' diameter
sphere) for stepping forward, kneeling down, moving around small
objects etc., but typically, only head movement is used until after
I tell them several times to "move your feet to look around that
object." This does not suprise me, since it is two very different
systems of movement, but it is still interesting.

Scale:  About a year ago, I posted a fleeting thought that scale,
in immersive systems, was a completely new dimension in which people
could move. (goto x=500, y=10020, z=23145 and scale=.000001 and
you will find my "house") (goto the corner, go left and go three
blocks. Grab the signpost and scale up 50,000x and I'll be there
waiting for you...) I am convinced of this now, after watching
person after person (myself included) get "lost" in scale and 
having to quit rather than deal with getting back roughly to
1 to 1 scale. (No, the softwate didn't have a return to scale
feature as such, unfortunately.) Scale is of paramount importance
in architecture, and if you cannot determine your scale relative
to a space, the true feeling of the space will be lost.

It is difficult to determine the difference between having an object
scaled way down, and being positioned a good distance away. Without
having some scale reference of your body in the virtual world, it
is impossible. The proprioceptive sense as well as reach of the
arms are the clues that are available in this system. (ie. reach
out with the pointer, if the arrows goes through the building, it
is scaled down, if it doesn't touch it, you are moved away from it.)
There are other, more subtle clues such as paralax (sp?), but this
is not helpful for determining exact scale. Problems such as being
the size of a mouse (reach) and having a 6 foot eye level cause
very strange perceptual understandings... Also, if there is no way
to keep a constant distance between the floor and your eye, it is
difficult to keep movement correct to keep perception consistant
and you end up with misunderstandings of the size of the building
relative to yourself.


I appologize for the rambling nature of this post, but it was meant
only as a series of somewhat connected ideas that might lend
themselves toward discussion individually later on.

Rick Zobel
NCSU School of Design
rick@oscar.sod.ncsu.edu