Page 150 - Intelligent Communication Systems

CHAPTER 1 /TELESENSATION 1 29
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The shutter glasses provide a stereoscopic view. On the basis of the movement
information, the images of the virtual person or object is deformed and displayed
on the screen to match the viewer's perspective.
In the conventional video conference system, participants can meet face to
face. However, it is very difficult to make eye contact and to have different views
of objects according to the viewer's perspective. In the real world, a viewer can
take a side view of an object just by moving to the side of the object. In the vir-
tual space teleconferencing system, participants can make eye contact and take
different views of the object to match their perspective. In the conventional video
conference system, a participant cannot go inside the scene displayed on the
screen, whereas in the virtual system he or she can enter the virtual space, walk
through it, and grasp a virtual object by means of hand gesture, even feeling the
heft of the object. To summarize, a viewer in the virtual world, can have a stereo-
scopic view of an object. This is called stereoscopic display. The viewer can
enter the virtual world and walk through it. This is called walk-through. The
viewer can take different views of the object according to his or her viewpoint.
This is called interaction. The viewer can touch and grasp a virtual object and
feel its heft. This is called force feedback. In the virtual world, even a collision
can be detected.
To accomplish these functions, the viewer wears shutter glasses or a head-
mounted display; this gives a stereoscopic view of the object, because the right
image of the object enters the right eye and the left image enters the left eye.
When the technologies of the lenticular screen and holography have been devel-
oped enough, viewers should be able to have a stereoscopic view with the naked
eye. This involves detecting the viewer's viewpoint via a sensor attached near
the viewer's eye and, based on this information, adjusting, the object's display
on the screen. Object handling with hand gesture is accomplished by means of
a data glove with sensor, that detects hand shape and hand motion. Again, this
information is used to adjust display of the object. The technology for detect-
ing hand motion and hand shape without use of a data glove is currently under
study.

11.2 HISTORY OF VIRTUAL REALITY

Research into VR started in the 1960s. I.E. Sutherland developed a prototype of
the head-mounted display. Dr. G. W. Furnes of Washington University developed
a virtual flight simulator in the 1970s. An interactive art theater was developed
in which a human being enters into a virtual scene as an actor or actress. Tele-
existence research has also been conducted. A viewer enters a virtual space for
training or operation of equipment as if he or she were there. The VPL company
of the United States developed a system with a head-mounted display and a data
glove for commercial purposes.