Virtual Reality

INTRODUCTION:				Human vision provides the most of information
What is virtual reality?				passed to our brain and captures most of our
Virtual reality (VR) is a technology which allows a				attention. Therefore the stimulation of the visual
user to interact with a computer-simulated				system plays a principal role in “fooling the
environment, whether that environment is a				senses” and has become the focus of
simulation of the real world or an imaginary world.				research.
It is an artificial environment that is created with				VIRTUAL REALITY TRACKING SYSTEMS:
software and presented to the user in such a				Tracking devices are intrinsic components in any
way that the user suspends belief and accepts it				VR system. These devices communicate with the
as a real environment. On a computer, virtual				system's processing unit, telling it the orientation
reality is primarily experienced through two of the				of a user's point of view. In systems that allow a
five senses: sight and sound				user to move around within a physical space,
Most current virtual reality environments are				trackers detect where the user is, the direction
primarily visual experiences, displayed either on a				he is moving and his speed. There are several
computer screen or stereoscopic displays, but				different kinds of tracking systems used in VR
some simulations include additional sensory				systems, but all of them have a few things in
information, such as sound through speakers or				common. They can detect six degrees of
headphones.				freedom (6-DOF) -- these are the object's
Virtual reality can be divided into:				position within the x, y and z coordinates of a
- The simulation of a real environment for training				space and the object's orientation. Orientation
and education.				includes an object's yaw, pitch and roll.
- The development of an imagined environment				From a user's perspective, this means that when
for a game or interactive story.				you wear an HMD, the view shifts as you look up,
HISTORY:				down, left and right. It also changes if you tilt your
The concept of virtual reality has been around for				head at an angle or move your head forward or
decades, even though the public really only				backward without changing the angle of your
became aware of it in the early 1990s.				gaze. The trackers on the HMD tell the CPU
Mid of 1950: Cinematographer Named Morton				where you are looking, and the CPU sends the
Heilig & Device: Sensorama				right images to your HMD's screens
Envisioned a theatre experience that would				Every tracking system has a device that
stimulate all his audiences’ senses, drawing				generates a signal, a sensor that detects the
them in to the stories more effectively. He build a				signal and a control unit that processes the signal
console in 1960 called the Sensorama that included				and sends information to the CPU. Some systems
a stereoscopic display, fans, odor emitters, stereo				require you to attach the sensor component to
speakers and a moving chair. He also invented a				the user (or the user's equipment). In that kind of
head mounted television display designed to let a				system, you place the signal emitters at fixed
user watch television in 3-D. Users were passive				points in the environment. Some systems are the
audiences for the films, but many of Heilig’s				other way around, with the user wearing the
concepts would find their way into the VR field.				emitters while surrounded by sensors attached to
In 1961: Philco Corporation engineers &				the environment.
Device: Headsight				The signals sent from emitters to sensors can
Developed the first HMD in 1961, called the				take many forms, including electromagnetic
Headsight. The helmet included a video screen and				signals, acoustic signals, optical signals and
tracking system, which the engineers linked to a				mechanical signals. Each technology has its own
closed circuit camera system. They designed the				set of advantages and disadvantages.
HMD for use in dangerous situations -- a user				ELECTROMAGNETIC TRACKING SYSTEMS:
could observe a real environment remotely,				Magnetic trackers are the most often used
adjusting the camera angle by turning his head.				tracking devices in immersive applications.Measure
Bell Laboratories used a similar HMD for helicopter				magnetic fields generated by running an electric
pilots. They linked HMDs to infrared cameras				current sequentially through three coiled wires
attached to the bottom of helicopters, which				arranged in a perpendicular orientation to one
allowed pilots to have a clear field of view while				another. Each small coil becomes an
flying in the dark.				electromagnet, and the system's sensors
In 1965: A Computer Scientist Named Ivan				measure how its magnetic field affects the other
Sutherland				coils. This measurement tells the system the
Envisioned what he called the “Ultimate				direction and orientation of the emitter. A good
Display.” Using this display, a person could look				electromagnetic tracking system is very
into a virtual world that would appear as real as				responsive, with low levels of latency.
the physical world the user lived in. This vision				One disadvantage of this system is that anything
guided almost all the developments within the field				that can generate a magnetic field can interfere in
of virtual reality. Sutherland’s concept included:				the signals sent to the sensors.
- A virtual world that appears real to any				ULTRA SONIC TRACKERS:
observer, seen through an HMD.				Emit and sense ultrasonic sound waves to
- A computer that maintains the world model in				determine the position and orientation of a target.
real time.				Most measure the time it takes for the ultrasonic
- The ability for users to manipulate virtual				sound to reach a sensor. Usually the sensors are
objects in a realistic, intuitive way.				stationary in the environment -- the user wears
For years, VR technology remained out of the				the ultrasonic emitters. The system calculates the
public eye. Almost all development focused on				position and orientation of the target based on
vehicle simulations until the 1980s.				the time it took for the sound to reach the
In 1984: Michael McGreevy & Device:				sensors.
Human-Computer Interface (Hci)				Disadvantages: Sound travels relatively slowly, so
Began to experiment with VR technology as a				the rate of updates on a target's position is
way to advance human-computer interface (HCI)				similarly slow. The environment can also adversely
designs. HCI still plays a big role in VR research,				affect the system's efficiency because the speed
and moreover it lead to the media picking up on				of sound through air can change depending on the
the idea of VR a few years later.				temperature, humidity in the environment.
In 1987: Jaron Lanier coined the term Virtual				OPTICAL TRACKING DEVICES:
Reality in 1987.				Use light to measure a target's position and
VIRTUAL REALITY ENVIRONMENT:				orientation. The signal emitter in an optical device
Other sensory output from the VE system				typically consists of a set of infrared LEDs. The
should adjust in real time as a user explores the				sensors are cameras that can sense the emitted
environment. Sensory stimulation must be				infrared light. The LEDs light up in sequential pulses.
consistent if a user is to feel immersed within a				The cameras record the pulsed signals and send
VE. If the VE shows a perfectly still scene, you				information to the system's processing unit.
wouldn’t expect to feel gale-force winds.				Disadvantages: Infrared radiation can also make a
Likewise, if the VE puts you in the middle of a				system less effective.
hurricane, you wouldn’t expect to feel a				MECHANICAL TRACKING SYSTEM:
gentle breeze or detect the scent of roses.				Rely on a physical connection between the
Lag time between when a user acts and when				target and a fixed reference point. A common
the virtual environment reflects that action is				example of a mechanical tracking system in the
called latency. Latency usually refers to the delay				VR field is the BOOM display. A BOOM display is
between the time a user turns his head or moves				an HMD mounted on the end of a mechanical arm
his eyes and the change in the point of view,				that has two points of articulation. The system
though the term can also be used for a lag in				detects the position and orientation through the
other sensory outputs. Studies with flight				arm. The update rate is very high with mechanical
simulators show that humans can detect a				tracking systems, but the disadvantage is that
latency of more than 50 milliseconds. When a user				they limit a user's range of motion.
detects latency, it causes him to become aware				VIRTUAL REALITY APPLICATIONS:
of being in an artificial environment and destroys				As the technologies of virtual reality evolve, the
the sense of immersion.				applications of VR become literally unlimited. It is
An immersive experience suffers if a user				assumed that VR will reshape the interface
becomes aware of the real world around him.				between people and information technology by
Truly immersive experiences make the user				offering new ways for the communication of
forget his real surroundings, effectively causing				information, the visualization.
the computer to become a non entity. In order to				Two approaches to current VR development:
reach the goal of true immersion, developers				- Modeling The Real World
have to come up with input methods that are				- Abstract Visualization.
more natural for users. As long as a user is				MODELLING THE REAL WORLD:
aware of the interaction device, he is not truly				ARCHITECTURE:
immersed.				An area in which virtual reality has tremendous
TYPES OF VIRTUAL REALITY:				potential is in architectural design. Already being
- Immersive virtual reality				created are architectural that allow designers and
- Non immersive virtual reality				clients to examine homes and office buildings,
- Semi immersive virtual reality				inside and out, before they're built. With virtual
IMMERSIVE VIRTUAL REALITY:				reality, designers can interactively test a building
In a virtual reality environment, a user				before construction begins.
experiences immersion, or the feeling of being				MILITARY:
inside and a part of that world. He is also able to				The military have long been supporters of VR
interact with his environment in meaningful ways.				technology and development. Training programs
The combination of a sense of immersion and				can include everything from vehicle simulations to
interactivity is called telepresence.				squad combat. On the whole, VR systems are
Computer scientist Jonathan Steuer defined it as				much safer and, in the long run, less expensive
“the extent to which one feels present in the				than alternative training methods. Soldiers who
mediated environment, rather than in the				have gone through extensive VR training have
immediate physical environment.” In other				proven to be as effective as those who trained
words, an effective VR experience causes you to				under traditional conditions.
become unaware of your real surroundings and				ANXIETY THERAPY:
focus on your existence inside the virtual				For years now, virtual environments have been
environment				used to treat anxiety problems with exposure
Jonathan Steuer proposed two main components				therapy. Psychologists treat phobias and post
of immersion:				traumatic stress disorder by exposing the patient
- Depth of information				to the thing that causes them anxiety and letting
- Breadth of information.				the anxiety dissipate on its own. But this proves
Depth of information refers to the amount and				difficult if your stressor is a battlefield in Iraq.
quality of data in the signals a user receives when				Military psychologists use simulated Iraq war
interacting in a virtual environment. For the user,				situations to treat soldiers. Other therapeutic VR
this could refer to a display’s resolution, the				uses include treating a fear of flying, fear of
complexity of the environment’s graphics,				elevators, and even a "virtual nicotine craving"
and the sophistication of the system’s audio				simulator for smoking addiction.
output.				VR TRAINING PROGRAMS:
Breadth of Information as the “number of				Virtual reality environments have also been used
sensory dimensions simultaneously presented.”				for training simulators. The earliest examples were
A virtual environment experience has a wide				flight simulators ("Microsoft Flight Simulator"), but
breadth of information if it stimulates all your				VR training has expanded beyond just that. There
senses. Most virtual environment experiences				are many modern military examples, including Iraqi
prioritize visual and audio components over other				cultural situations and battlefield simulators for
sensory-stimulating factors, but a growing number				soldiers.
of scientists and engineers are looking into ways				Flight simulators are a good example of a VE
to incorporate a users’ sense of touch.				system that is effective within strict limits. In a
Systems that give a user force feedback and				good flight simulator, a user can take the same
touch interaction are called haptic systems.				flight path under a wide range of conditions. Users
NON IMMERSIVE VIRTUAL REALITY:				can feel what it's like to fly through storms, thick
Non-immersive systems, as the name suggests,				fog or calm winds. Realistic flight simulators are
are the least immersive implementation of VR				effective and safe training tools, and though a
techniques. Using the desktop system, the virtual				sophisticated simulator can cost tens of thousands
environment is viewed through a portal or window				of dollars, they're cheaper than an actual aircraft
by utilizing a standard high resolution monitor.				(and it's tough to damage one in an accident). The
Interaction with the virtual environment can occur				limitation of flight simulators from a VR
by conventional means such as keyboards, mice				perspective is that they are designed for one
and trackballs or may be enhanced by using 3D				particular task. You can't step out of a flight
interaction devices.				simulator and remain within the virtual
SEMI-IMMERSIVE VIRTUAL REALITY:				environment, nor can you do anything other than
- A large screen monitor				pilot an aircraft while inside one.
- A large screen projector system				VIRTUAL REALITY IN EDUCATION:
- Multiple television projection systemssimilar to				Virtual reality (VR) can be described as a
the IMAX theatres sing a wide field of view,				cutting-edge technology that allows students to
these systems increase the feeling of immersion				step through the computer or television screen
or presence experienced by the user				into a three dimensional, computer-simulated world
Semi-immersive systems therefore provide a				to learn.
greater sense of presence than non-immersive				MULTIPLAYER ONLINE GAMING:
systems and also a greater appreciation of scale.				One result of virtual-reality research is the
In addition, images can be provided that are of a				existence of entirely separate virtual worlds,
far greater resolution than HMDs and this				inhabited entirely by the avatars of real world
implementation provides the ability to share the				users. These worlds are sometimes referred to
virtual experience. This may have a considerable				as massively multiplayer online games, and the
benefit in educational applications as it allows				World of Warcraft is the largest virtual gaming
simultaneous experience of the VE which is not				world in use now, with 11.5 million subscribers.
available with head-mounted immersive systems.				THE NINTENDO WII:
VIRTUAL REALITY INTERACTIVITY:				Probably the most successful cousin of virtual
Immersion within				reality on the market today is the Nintento Wii.
a virtual environment is one thing, but for a user				The Wii owes its motion capture and intuitive
to feel truly involved there must also be an				interaction concepts to the virtual reality
element of interaction. Early applications using the				technologies of the past. The controller is basically
technology common in VE systems today allowed				a simplified version of the "virtual reality glove."
the user to have a relatively passive experience.				Both the Wiimote and the Wii Fit offer users
Users could watch a pre-recorded film while				another way of interacting with their virtual
wearing a head-mounted display (HMD). They				environment without having to wear any bulky
would sit in a motion chair and watch the film as				equipment.
the system subjected them to various stimuli,				MEDICAL PROCEDURES:
such as blowing air on them to simulate wind.				Modern medicine has also found many uses for
While users felt a sense of immersion,				virtual reality. Doctors can interact with virtual
interactivity was limited to shifting their point of				systems to practice procedures or to do tiny
view by looking around. Their path was				surgical procedures on a larger scale. Surgeons
pre-determined and unalterable.				have also started using virtual "twins" of their
Interactivity depends on many factors. Steuer				patients, to practice for surgery before doing the
suggests that three of these factors are speed,				actual procedure. In medicine, staff can use virtual
range and mapping. Steuer defines speed as the				environments to train in everything from surgical
rate that a user's actions are incorporated into				procedures to diagnosing a patient. Surgeons have
the computer model and reflected in a way the				used virtual reality technology to not only train
user can identify by means of senses. Range				and educate, but also to perform surgery
refers to how many possible outcomes could				remotely by using robotic devices.
result from any particular user action. Mapping is				Researchers are using virtual reality technology to
the system's ability to produce natural results in				create 3-D ultrasound images to help doctors
response to a user's actions.				diagnose and treat congenital heart defects in
Navigation within a virtual environment is one kind				children.
of interactivity. If a user can direct his own				ABSTRACT VISUALISATION:
movement within the environment, it can be				The other most commonly found approach to
called an interactive experience. Most virtual				VR application is in those areas where large
environments include other forms of interaction,				quantities of abstract data need to be
since users can easily become bored after just a				manipulated, examined or accessed. Such
few minutes of exploration.				visualizations range from common datasets such
Computer Scientist Mary Whitton points out that				as maps, to micro and macro structures such as
poorly designed interaction can drastically reduce				molecular architecture or social networks. By
the sense of immersion, while finding ways to				combining VR with Geographical Information
engage users can increase it. When a virtual				Systems (GIS), geographical information can be
environment is interesting and engaging, users are				explored in three dimensions or the information
more willing to suspend disbelief and become				contained within a computer database can be
immersed.				visualized and navigated.
True interactivity also includes being able to				Almost any situation that requires interaction with
modify the environment. A good virtual				information (even mathematical algorithms can
environment will respond to the user's actions in a				benefit from VR visualization. Users are able to
way that makes sense, even if it only makes				visualize and interact with information through
sense within the realm of the virtual environment.				multi-dimensional graphical representations
If a virtual environment changes in outlandish and				(combined with text clues). Such representations
unpredictable ways, it risks disrupting the user's				increase users' ability to analyze the underlying
sense of telepresence.				data by negating the need for them to construct
VIRTUAL REALITY INTERFACES:				their own mental image of the data.
DATAGLOVES:				VIRTUAL REALITY FORMATS:
Data gloves offer a simple means of gesturing				As the number of applications of virtual reality
commands to the computer. Rather than punching				(VR) has grown, there have also been changes in
in commands on a keyboard, which can be tricky				the different formats of VR-type software. Each
if you're wearing a head-mounted display or are				format has differing approaches to, and varying
operating the BOOM, you program the computer				degrees of, three-dimensionality, immersion and
to change modes in response to the gestures				interaction.
you make with the data gloves.				VIRTUAL REALITY & INTERNET:
Pointing upwards may mean zoom in; pointing				Some programmers envision the Internet
down, zoom out. A shake of your fist may signal				developing into a three-dimensional virtual space,
the computer to end the program. Some people				where you navigate through virtual landscapes to
program the computer to mimic their hand				access information and entertainment. Web sites
movements in the simulation; for instance, to see				could take form as a three-dimensional location,
their hands while conducting a virtual symphony.				allowing users to explore in a much more literal
WANDS:				way than before. Programmers have developed
Wands, the simplest of the interface devices,				several different computer languages and Web
come in all shapes and variations. Most incorporate				browsers to achieve this vision. Some of these
on-off buttons to control variables in a simulation				include:
or in the display of data. Others have knobs, dials,				- Virtual Reality Modeling Language (VRML) - the
or joy sticks. Their design and manner of				earliest three-dimensional modeling language for
response a re tailored to the application.				the Web.
Most wands operate with six degrees of				- 3DML - a three-dimensional modeling language
freedom; that is, by pointing a wand at an object,				where a user can visit a spot (or Web site)
you can change its position and orientation in any				through most Internet browsers after installing a
of six directions: forward or backward, up or				plug-in.
down, or left or right.				- X3D - the language that replaced VRML as the
STAIR STEPPERS:				standard for creating virtual environments in the
Stair steppers are an example of the limitless				Internet.
manifestations of interface devices. As part of a				1. X3D superseded VRML97. Since VRML97 is a
simulated battlefield terrain, engineers from an				subset of the X3D standard, VRML files
army research lab outfitted a stair stepper with				can still be processed by newer X3D browsers.
sensing devices to detect the speed, direction,				- Collaborative Design Activity (COLLADA) - a
and intensity of a soldier's movements in				format used to allow file interchanges within
response to the battlefield scenes projected onto				three-dimensional programs.
a head-mounted display. The stair stepper				DEVELOPMENT DIFFICULTIES
provided feedback to the soldier by making the				- Bottleneck of transmission bandwidth
stairs easier or more difficult to climb.				- 3-D visualization technology closely integrated
VIRTUAL REALITY SYSTEMS:				with the data warehouse
HEAD-MOUNTED DISPLAY:				- Preserve the integrity of the database in a
Looking like oversized motorcycle helmets,				shared user environment
head-mounted displays are actually portable				APPLICATION IN THE INTERNET
viewing screens that add depth to otherwise flat				- Virtual Theme Park
images. If you look inside the helmet you will see				- Virtual Shopping Mall
two lenses through which you look at a viewing				- Real-time Conferencing
screen. As a simulation begins, the computer				- Flight Simulation
projects two slightly different images on the				- Gaming Experience
screen: one presenting the object as it would be				POTENTIAL VR FOR E-COMMERCE:
seen through your right eye, the other, through				Three-dimensional (3-D), multi-user, online
your left. These two stereo images are then				environments constitute a revolution of
fused by your brain into one 3D image.				interactivity by creating a compelling online
To track your movements, a device on top of				experience.
the helmet signals your head movements relative				VE offers e-shoppers the ability study the
to a stationary tracking device. As you move				product carefully.
your head forwards, backwards, or sideways, or				Provides the e-shoppers confidence that what
look in a different direction, a computer continually				they see is actually what they will get. Give better
updates the simulation to reflect your new				description on product.
perspective.				VIRTUAL REALITY FOR
Because head-mounted displays block out the				TELECOMMUNICATION:
surrounding environment, they are favored by VR				Tele-education, telemedicine, Tele-banking,
operators who want the wearers to feel				Tele-work becomes possible. It improves new
absorbed in the virtual environment, such as in				ways for people to interact with each other and
flight simulators. And as you might expect, these				computer.
displays also are popular with the entertainment				Application of VR and Telecommunication
industry.				- Telemedicine
Data gloves and wands are the most common				- Tele-education
interface devices used with head-mounted				- Tele-training
displays.				- Tele-banking
BOOM:				- Tele-work
The Binocular Omni Orientation Monitor, or BOOM,				VR TECHNOLOGY IN TELECOMMUNICATION:
is similar to a head-mount except that there's no				Using VR to manage Broadband
fussing with a helmet. The BOOM's viewing box is				Telecommunication Networks
suspended from a two-part, rotating arm. Simply				- VR user interfaces for broadband network
place your forehead against the BOOM's two				- Allows network structure, information flow to
eyeglasses and you're in the virtual world. To				be visualized
change your perspective on an image, grab the				- So, immediately responds through VR, reduce
handles on the side of the viewing box and move				error
around the image in the same way you would if it				- Act as though in the real world using data
were real: Bend down to look at it from below;				gloves.
walk around it to see it from behind. Control				VIRTUAL REALITY CHALLENGES AND
buttons on the BOOM handles usually serve as				CONCERNS:
the interface although you can hook up data				Most of today’s VR applications do not
gloves or other interface devices.				conform to reality and have poor quality, but are
				still very useful but must be improved a lot to
CAVE:				allow more comfortable and intuitive
One of the newest, most "immersive" virtual				Interaction with virtual worlds.
environments is the CAVE (CAVE Automatic				The big challenges in the field of virtual reality are
Virtual Environment).				developing better tracking systems, finding more
It provides the illusion of immersion by projecting				natural ways to allow users to interact within a
stereo images on the walls and floor of a				virtual environment and decreasing the time it
room-sized cube. Several persons wearing				takes to build virtual spaces. While there are a
lightweight stereo glasses can enter and walk				few tracking system companies that have been
freely inside the CAVE.				around since the earliest days of virtual reality,
SENSUAL TECHNOLOGIES:				most companies are small and don’t last very
A variety of input devices like data gloves,				long.
joysticks, and hand-held wands allow the user to				The major interest was paid to visual feedback
navigate through a virtual environment and to				and visual display technologies resolution is
interact with virtual objects. Directional sound,				Significantly below eye’s resolving capability,
tactile and force feedback devices, voice				luminance and color ranges do not cover the
recognition and other technologies are being				whole eye’s perception range (brightness
employed to enrich the immersive experience and				range and gamut respectively), and finally the field
to create more "sensualized" interfaces.				of
SHARED VIRTUAL ENVIRONMENTS:				View is relatively narrow. All these disadvantages
Three networked users at different locations				make virtual worlds appear “artificial” and
(anywhere in the world) meet in the same virtual				unreal, which severely contributes to the simulator
world by using a BOOM device, a CAVE system,				sickness.
and a Head-Mounted Display, respectively. All				Without well-designed hardware, a user could
users see the same virtual environment from				have trouble with his sense of balance or inertia
their respective points of view. Each user is				with a decrease in the sense of telepresence, or
presented as a virtual human (avatar) to the				he could experience cyber sickness, with
other participants. The users can see each other,				symptoms that can include disorientation and
communicated with each other, and interact with				nausea. Not all users seem to be at risk for cyber
the virtual world as a team.				sickness -- some people can explore a virtual
HUMAN FACTORS:				environment for hours with no ill effects, while
As virtual environments are supposed to simulate				others may feel queasy after just a few minutes
the real world, by constructing them we				Some psychologists are concerned that
musthave knowledge how to “fool the				immersion in virtual environments could
user’s senses” This problem is not a trivial				psychologically affect a user.
taskand the sufficiently good solution has not yet				CONCLUSION:
been found: on the one hand we must give				Technology has transformed the world in which
theuser a good feeling of being immersed, and on				we live, changing how we spend our time, how
the other hand this solution must be feasible.				we understand ourselves, and how we interact
• Sight................. 70 %				with others. Technological innovation results in
• hearing.............. 20 %				social and economic change. Thus, VR will lead to
• smell ..................5 %				the development of a Virtual World. And it is the
• touch..................4 %				Virtual World that promises to restructure human
• taste ...................1 %				life and activity.

Sims Divine

Virtual Reality

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