What is Virtual reality?
Virtual Reality is a computer generated, multi-
sensory information program which tracks a
user in real time i.e. computer system is used
to create an artificial world in which the user
has the impression of being in that world ,with
the ability to navigate through and manipulate
objects in that world.
History of VR
In 1950s, flight simulators were built by US
Air Force to train student pilots.
In 1965, a research program for computer
graphics called “The Ultimate Display” was
In 1988, commercial development of VR
In 1991, first commercial entertainment VR
system "Virtuality" was released.
Window on a world
Types of Virtual Reality
In a completely immersive system , the user
becomes part of the simulated world , rather
than the simulated world being a feature of
the user's own world.
Display devices like head-mounted display
and stereo spectacles ; provide a 3-D virtual
space in user's vision.
The first “immersive VR systems” have
been the flight simulators where the
immersion is achieved by mixture of real
hardware and virtual imagery.
Augmented reality (AR) is a term for a live direct or an
indirect view of a physical, real-world environment whose
elements are augmented by computer-generated sensory
input, such as sound or graphics, haptic feedback.
Augmented reality does not create a simulation of reality.
Instead, it takes a real object as the foundation and
incorporates technologies that deepen a person’s
understanding of the subject.
AR technology includes head-mounted
displays and virtual retinal displays for visualization
purposes, and construction of controlled environments
containing sensors and actuators.
The superimposing of physical reality windows
onto a virtual reality environment , such that
participants of the virtual reality also see the
physical reality object.
e.g. A The virtual environment is projected onto a
large display on a single surface or a multiple
projection “CAVE” from different directions,
which can serve a group of people viewing the
same content simultaneously.
Desktop-based virtual reality involves displaying
a 3-dimensional virtual world on a
regular desktop display without use of any
specialized movement-tracking equipment.
It is cost-effective when compared to the
However they lack the immersion quality,
Because there is no sense of peripheral vision,
limiting the user's ability to know what is
happening around them.
Devices used in VR
HMD(Head Mounted Display)
A head-mounted display is a device, worn on the
head that has a small display optic in front of one
eye (monocular HMD) or each eye (binocular
HMD) to reproduce a stereoscopic vision.
Training with HMDs involve a wide range of
applications from driving, welding and spray
painting, flight and vehicle simulators, dismounted
soldier training and medical procedure training.
Haptic technology is a tactile feedback
technology involving that the man-machine
interface system should be capable of recording
the movements of the human hand and also of
replicating virtual forces.
E.g. is Cyber Grasp: It is a haptic feedback
interface that enables; users are able to explore
the physical properties of computer-generated
3D objects and manipulate them in a simulated
and tactile feedback
(Cave Automatic Virtual Environment)
Surround-screen, surround-sound, projection-based VR
Illusion of immersion is created by projecting 3D computer
graphics into a cube composed of display screens that
completely surround viewer.
coupled with head and hand tracking systems.
Sound system provides audio feedback. Sensors within the
room track the viewer's position to align the perspective
Viewer explores virtual world by moving around inside
cube and grabbing objects.
A 3D scanner is a device that analyses a real-world
object or environment to collect data on its shape and
possibly its appearance (i.e. colour). The collected
data can then be used to construct digital, three
They are extensively used for the entertainment
industry in the production of movies and video games
, design , documentation of cultural artefacts involved
in the design.
The BOOM (Binocular Omni-Orientation
Monitor) is a head-coupled stereoscopic display
Screens and optical system are housed in a box
that is attached to a multi-link arm.
The user looks into the box through two holes,
sees the virtual world, and can guide the box to
any position within the operational volume of the
Head tracking is accomplished via sensors in the
links of the arm that holds the box.
The Data Glove consists of a lightweight nylon
glove with optical sensors mounted along the
fingers which accurately and repeatedly measure
the position and movement of the fingers and
Data gloves are commonly used in virtual
reality environments where the user sees an image
of the data glove and can manipulate the
movements of the virtual environment using the
The Projector has extremely demanding requirements
for its graphics hardware. It consists of 3D projection
system, mirrors and projection walls.
Shutter glasses enable us to view virtual image or video
more deliberately through them. Shutters in the glasses
are synchronized with the display system using Infrared
Motion tracking uses a combination of computer
chips, sensors and cameras to record humans in
motion and create digital doppelgangers that move
the same way.
Designed for head and hand tracking in VR games,
simulations, animations, and visualizations.
For example, Polhemus STAR*TRAK is a long range
motion capture system that can operate in a wireless
mode (totally free of interface cables) or with a thin
Electromagnetic tracking systems measure and sense
magnetic fields generated by running an electric current
through three coiled wires .The system's sensors measure
how its magnetic field affects the other coils. This
measurement tells the system the direction and orientation of
Acoustic tracking systems emit and sense ultrasonic sound
waves to determine the position and orientation of a target.
The system calculates the position and orientation of the
target based on the time it took for the sound to reach the
Mechanical tracking systems rely on a physical connection
between the target and a fixed reference point. E.g. is A
BOOM display is an HMD mounted on the end of a
mechanical arm. The system detects the position and
orientation through the arm.
Applications of VR
Rehabilitation and help to disable people
It is also possible to create dialogue based on hand
gestures between a deaf real human and a deaf virtual
human using Sign Language. Muscular dystrophy
patients can learn to use a wheelchair through VR.
With the advent of realistic virtual humans, it will be
possible to recreate situations in a Virtual
World, immersing the real patient into virtual scenes.
Therapists may also use VR to treat people who are
afraid of heights.
With the simulation of the entire physiology of the human
body , the effects of various illnesses or organ replacement will
be visible. The surgeon using an
HMD and Data Gloves may have a complete simulated view of
the surgery. For medical students learning how to operate, the
best way would be to start with 3D virtual patients.
Education and training
The most common example is the flight simulator . They
have lower operating costs and are safer to use than real
aircraft. They also allow the simulation of dangerous
scenarios not allowable with real aircraft.
Many areas of design are typically 3D for example, the design of
a car shape, where the designer looks for sweeping curves and
good aesthetics from every possible view.
Operations in dangerous environments
Workers in radioactive, space, or toxic environments could be
relocated to the safety of a VR environment where they could
'handle' any hazardous materials without any real danger.
Moreover, the operator's display can be augmented with
important sensor information, warnings and suggested
In this area, VR allows the future customer to “live” in his/her a
new house before it is built. He/she could get a feel for the
experiment with different lighting schemes, furnishings, or even
the layout of the house itself.
VRML (Virtual Reality Modeling Language)
standard language for interactive simulation within
the World Wide Web.
allows to create "virtual worlds" networked via the
Internet and hyperlinked with the World Wide Web.
Aspects of virtual world display, interaction and
internetworking can be specified using VRML
without being dependent on special gear like HMD.
VR models can be viewed by Netscape or IE with a
Virtual Reality Studio ($100)
Sense8 World Tool Kit (WTK) (over $1000)
Autodesk Cyberspace Development kit
available in market
Virtual Reality is at a critical design phase. The theories behind
its design and operation are still being written. There are 61,400
international commercial companies producing VR. There are
approximately 3,600 educational institutions which use VR.
Advantages of VR
Visualization of complicated, large data is helpful for
understanding and analysis.
VR offers us a new way to interact with computer.
VR enables us to experience the virtual world that is
impossible in real world.
VR is changing our life, eventually VR will
increasingly become a part of our life.