Paper
Introduction
In the not so distant past, all mechanical drawings and
blueprints were created by hand. Models of the parts were
then made, also by hand. Mistakes could cost a great deal of
time and money. Then the design world was revolutionized by
computer aided drafting. This new tool, along with the
addition of rapid prototyping, has saved industry a countless
amount of hours and money.
As efficient as the part modeling systems of today are,
a new tool is developing that may once again change the part
modeling process for good. Virtual reality systems can allow
a person to “walk” through a new building or examine a new
part before a mock up or model is ever made, allowing changes
to be implemented before anything is ever built. Although
only considered to be in its infancy stages, virtual reality
will soon become an integral part of the design process.
Virtual Reality Background
The term virtual reality describes a computer program
that stimulates some or all of the five senses in order to
create an “illusion of being somewhere or doing something”
(Bates 53). It can consist of programs that allow the user
to “fly through” a design, or it can be a room complete with
three dimensional graphics, sound, and the sense of touch.
In the world of virtual reality, there are six degrees-of-
freedom, or in other words, six different types of movement.
In addition to the normal up/down and left/right movements,
the user can also pitch up or down, angle left or right, move
forward or backward and rotate left or right. A normal
drawing from CAD can become a virtual environment that can
almost be percepted as real (Teschler 60).
Virtual Reality Applications
Numerous virtual reality applications are available on
the market, ranging from a price of several hundred dollars
to millions of dollars. As mentioned above, the simplest of
the virtual reality programs is the fly through program.
This type of application can be run from a personal computer
without the need of expensive hardware. Some of these
programs, such as ADAMS form Mechanical Dynamics and Working
Model from Knowledge Revolution allow designs to be subjected
to a kinematic analysis in order to see how parts will
perform. These types of applications are used extensively in
the automotive industry (Puttre 21).
Three Dimensional Graphics
The next step up is to make the virtual environment
three dimensional. This is done using a 3-D graphics
generator such as stereographic goggles, also known as head
mounted displays (HMD’s) (Derra 46). A simple movement of
the head will change the perspective seen through the
goggles, just as in real life.
Although the use of a HMD can provide a totally unique
perspective it increased cost must be considered. For
complicated, 3-D virtual systems, a graphics accelerator and
a six degree-of-freedom mouse are needed (Teschler 62).
These items coupled with the cost of the HMD can drive the
price up to around 130,000 dollars (Derra 46).
Virtual Touch
In addition to sight, virtual reality can also include
the sense of touch. Cybernet Systems Corporation has
developed a hand held system that will give the user a sense
of pressure when obstructions in the virtual room are
reached (Schut 23). Prosolvia Clarus of Sweden has developed
a pair of cybergloves that will produce a feeling of
restraint when trying to penetrate a barrier and a feeling
of weight when holding an object (Bates 54).
Advanced Virtual Reality Applications
The majority of virtual reality programs in industry
today are the fly through programs used with either normal
computer screens or goggles. However there are some advanced
virtual reality systems in use on a small scale. The two
systems in use today are the Cave Automatic Virtual
Environment (Cave) and Simulation Based Design (SBD) system.
These two cutting edge systems are very expensive and in use
mainly at universities and in the automotive and aerospace
industries.
The Cave system at the Argonne National Laboratory in
Argonne, Illinois is typical of most Cave systems. “Images
are projected onto the floor and on stretched Mylar screens
forming the front and two side walls for 180 (degree) of
immersed visualization” (Bates 55). Users wear special
goggles that cause depth perception, and the system is
controlled by mouse and joystick controls (Bates 55).
The Cave system is also employed at Caterpillar in
Peoria, Illinois. The virtual reality environment is created
by importing drawings from the Pro/Engineer CAD system. The
Cave system is equipped with a steering wheel, shifter, seat
and other controls so the imported design can actually be
“driven” (Teschler 62). Different environments, such as a
cornfield or a landfill, can be utilized during the
simulation. Managers of the new Caterpillar technology
believe that the device has significantly reduced product
development time (Bates 56).
Simulation Based Design (SBD) was started by the Defense
Advanced Research Projects Agency, in conjunction with
several private defense contractors. SBD combines CAD with
virtual reality and kinematic analysis to produce realistic
simulations. Using a SBD program, Lockheed Martin had
successfully produced simulations of Navy ship deck gun
firing arcs. As SBD technology continues to progress, design
times will decrease, physical prototypes will be eliminated,
and initial design quality will be improved (Puttre 22).
Although Cave and SBD systems are available, they are
not in use by many companies yet. Most companies refrain
from such a large system because of its high cost. The
initial cave system can cost around $400,000, and the
computers to run the graphic displays can cost an additional
$30,000 to $300,000 (Derra 46). It is not widely believed
that the benefits of these systems outweigh the initial costs
at this point in time.
Conclusion
Every new technology requires time before general
acceptance is achieved. Virtual reality technology has not
been around for long, so wide acceptance has generally not
been seen. However, as the technology continues to improve
and the cost decreases, virtual reality will find a home in
industry. In the not so distant future, virtual reality
simulations will be the norm and prototypes will be a thing
of the past.
Abstract
Virtual Reality technology is in the beginning stages,
but will soon have a large impact on product development.
Several different types of virtual technologies are available
today. The basic systems operate on normal computers. Three
dimensional systems are available, and some even offer the
sense of touch. Cave systems and SBD systems offer the most
options and best effects, but are costly and not in wide use.
More applications for virtual reality technology will seen as
the technology evolves.
Works Cited
Bates, Charles A. “Come on in, the VR is fine.” American
Machinist. v. 141, 1997. pp. 53-6.
Derra, Skip. “Virtual reality: development tool or research
toy?.” R & D Magazine. v. 40, 1998. pp. 45-50.
Dvorak, Paul. “Engineering puts virtual reality to work.”
Machine Design 29 Feb 1997. pp. 69-73.
Puttre, Michael. “Simulation-based design puts the virtual
world to work.” Design News v. 53, 1998. pp. 21-25.
Schut, Jan H. “Autofact showcases low-cost, high-function
software and the first touchy-feely CAD.” Plastics World
Jan 1997. pp. 22-26.
Teschler, Leland. “Walk-through realism slashes development
time.” Machine Design 25 May 1995. pp. 60-64.
Table of Contents
Abstract 1
Introduction 2
Virtual Reality Background 3
Virtual Reality Applications 3
Three Dimensional Graphics 3
Virtual Touch 4
Advanced Virtual Reality Applications 4
Conclusion 6
Works Cited 7
Appendix 8
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