Project_Virtual_reality_bak

8/7/2019 Project_Virtual_reality_bak

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ACKNOWLEDGMENT

It would be selfish on our part, if we do not thank the people wholend us their thoughts, ideas & gave immense invaluable

suggestions during the course of our design and development

process.

First and foremost we must thank Miss Sraboni Goswami, our

project advisor without whose constant support and advice the

project would not have been in today‟s position. We are thankful to

our friends, classmates and family members who gave us immense

support to complete the project successfully on time.

Finally, if there lies a driving force that kept us going, helped me

not to deviate from our goal, bear us with our long stints on the

computer, it is the constant support and blessing of our parents.



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CONTENTS

Content Page

Executive summary 3

Introduction 4

What is Virtual Reality 5

Origin of Virtual Reality 6

Virtual Reality: Modeling the real world 7

Four key elements in experiencing Virtual Reality 9

Four technologies that are critical for Virtual Reality 10

Four auxiliary technologies that are also important for VR 11

User interaction with Virtual Reality 12

Virtual Reality Devices 16

Levels of immersion within Virtual Reality 19

Applications of Virtual Reality 22

Advantages of Virtual Reality 27

Disadvantage of Virtual Reality 28

Recommendation 29

Conclusion 30

Bibliography 31



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EXECUTIVE SUMMARY

Virtual reality (VR) allows a user to interact with a computer-

simulated environment, be it a real or imagined one. Users can

interact with a virtual environment either through the use of

standard input devices. The simulated environment can be similar to

the real world. No matter how much people thrush out slogan, that

VR can present realistic scenarios, it can also be used to present

scenarios that otherwise would be impossible to experience. The

power of VR is that it can take the created world, real or fantastic,and allow a user to interact with it. VR can allow one or many

people to interact with computer-generated objects and worlds in

the way that they would interact with the real-world (or other)

equivalents. The VR world is effectively an interface that gives users

some feeling of existence within an artificial world created by

computer graphics. For this purpose a variety of visualization

systems and external hardware devices are used to enableinteraction with the VR world. Specialist hardware devices are

available that can give users a greater sense of immersion within

the world. Devices can also be designed to give users feedback from

the virtual world. The most important thing in VR since 1994 is not

the advance in the technologies, but increasing adoption of its

technologies and techniques to increase productivity, team

communication, and reduce costs. Thus VR is all in all a boom as VR

is now really real and is a multi-dimensional effort covering

everything from mechanical engineering and psychophysiology.



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INTRODUCTION

Virtual Reality is no more a dream or a science fiction story

anymore. It is a Reality, though Virtual, but hardly distinguishable

from the real or original. We can easily experience it and thoroughly

enjoy what it has to offer. Amazingly, Virtual Reality has found

widespread application and uses concerning the different facts in the

life of man. We often argue about the benefits of the advancement

of science and technology in various fields, but Virtual Reality needs

no corroboration for its positive uses and purposes. This is just the

beginning of the more far reaching progress that all of us are about

to witness in the sphere of Virtual Reality in future.

We have put in our best endeavor to apprise the reader about the

wonderfully amazing world of Virtual Reality and its uses and

applications. We hope that the reader shall find this project work

useful and informative.

VIRTUAL REALITY



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WHAT IS VIRTUAL REALITY?

Virtual reality (VR) is a technology which allows a user to interact

with a computer-simulated environment, be it a real or imagined

one. Most virtual reality environments are primarily visual

experiences, displayed either on a computer screen or through

special stereoscopic displays, but some simulations include

additional sensory information, such as sound through speakers or

headphones. Some advanced, haptic systems now include tactile

information, generally known as force feedback, in medical and

gaming applications. Users can interact with a virtual environment

either through the use of standard input devices such as a keyboard

and mouse, or through multimodal devices such as a wired glove,

the Polhemus boom arm, and/or omnidirectional treadmill. The

simulated environment can be similar to the real world.



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ORIGIN OF VIRTUAL REALITY

The origin of the term virtual reality is uncertain. It has been

credited to The Judas Mandala, a 1982 novel by Damien Broderick

where the context of use is somewhat different from todays Virtual

Reality. The VR developer Jaron Lanier claims that he coined the

term. A related term coined by Myron Krueger, "artificial reality",

has been in use since the 1970s. The concept of virtual reality was

popularized in mass media by movies such as Brainstorm and The

Lawnmower Man etc., and the VR research boom of the 1990s was

motivated in part by the non-fiction book Virtual Reality by Howard

Rheingold. The book served to demystify the heretofore niche area,

making it more accessible to less technical researchers and

enthusiasts, with an impact similar to what his book The Virtual

Community had on virtual community research lines closely related

to VR.

While virtual reality originally denoted a fully immersive tethered

system, the term has since been used to describe systems lacking

wired gloves, full body suits, etc., such as those driven by VRML and

X3D on the World Wide Web and occasionally even text-based

interactive systems such as MOOs or MUDs. Non-immersive virtual

reality uses a normal monitor, and the person manipulates the

virtual environment using a keyboard, a mouse, a joystick or a

similar input device. The term was used in the early 1990s to

denote 3D computer and video games, particularly first-person

shooters.



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VIRTUAL REALITY: MODELLING

THE REAL WORLD

Video or paintings can be used to represent certain limited

conditions, but a computer-based model is theoretically unbounded.

For example, the same model of an airport may be viewed under a

variety of programmed conditions (bad weather, night-time etc.).

The scope for designing worlds, and the objects within them, is

limitless as real-world constraints, such as gravity, dimension or

even common sense, do not have to apply.

Airplane simulator

Whilst VR can present realistic scenarios, it can also be used to

present scenarios that otherwise would be impossible to experience.A developer could construct a rocket for travel to distant galaxies,

or reconstruct the streets of ancient Pompeii. Theoretically such

boundless opportunity is available in any graphics medium,

dependent only on the skill and imagination of the illustrator. The

power of VR is that it can take the created world, real or fantastic,

and allow a user to interact with it. Interactivity is one of the core

elements of VR and separates it from other two and three-



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dimensional graphics mediums. VR can allow one or many people to

interact with computer-generated objects and worlds in the way

that they would interact with the real-world (or other) equivalents.

Users can apparently fly to distant galaxies or, if they so wish, stand

on the streets of Pompeii just before Vesuvius erupts!



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FOUR KEY ELEMENTS IN

EXPERIENCING

VIRTUAL REALITY

1. A virtual world an imaginary space, often (but not necessarily)

manifested through a medium.

2. Immersion (physical and mental) having a sense of “presence”

within an environment; this can be purely a mental state, or can be

accomplished through physical means Mental Immersion a state of

being deeply engaged, with suspension of disbelief [one can achieve

mental immersion with books, movies, … many different kinds of

media].

3. Physical Immersion bodily entering into a medium.

4. Interactivity in a virtual reality experience, participants are able

to move around and change their viewpoint, generally through

movements of their head.



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FOUR TECHNOLOGIES THAT

ARE CRITICAL FOR

VIRTUAL REALITY

1. The visual (and aural and haptic) displays that immerse the user

in the virtual world and that block out contradictory sensory

impressions from the real world.

2. The graphics rendering system that generates, at 20 - 30

frames/second, the ever-changing images.

3. The tracking system that continually reports the position and

orientation of the user‟s head and limbs.

4. The database construction and maintenance system for building

and maintaining detailed and realistic models of the virtual world.



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FOUR AUXILIARY

TECHNOLOGIES THAT ARE

ALSO IMPORTANT FOR VR

1. Synthesized sound, displayed to the ears, including directional

sound and simulated sound fields.

2. Display of synthesized forces and other haptic sensations to the

kinesthetic senses.

3. Devices, such as tracked gloves with pushbuttons, by which the

user specifies interactions with virtual objects.

4. Interaction techniques that substitute for the real interactions

possible with the physical world.



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USER INTERACTION WITH

VIRTUAL REALITY

The degree of interaction that users have in a VR world depends

loosely on engineering within the world itself and the hardware that

they use to interact with it. A VR world is effectively an interface

that gives users some feeling of existence within an artificial world

created by computer graphics. Users may be represented in the

world in a range of forms: as a complete virtual body, as a part of a

body such as a hand or as a controllable viewpoint. The world can

be engineered to give users control of elements within it, for

example a vehicle, and navigation can be enhanced by including

three-dimensional signposts, instruments or buttons. It is also

possible to add text or other two-dimensional graphic aids to a VR

world to assist users in their tasks.

A variety of visualisation systems and external hardware devices are

used to enable interactions with VR worlds. The level of 'immersion'

within a world is dependent upon the devices that are used, and the

sort of interactivity that is designed into the world. The most

common systems for viewing VR worlds can be summed up as



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• Projected

The user's field of vision is effectively filled by screens displaying

a projected virtual world. Projection may be onto large concave

screens in front of the user or within 'caves' or 'sheds' that users

walk into. The latter can fill a 360 degree field of vision.

• Headsets

Users wear stereoscopic glasses or head-mounted displays

(HMDs) which place small screens right in front of their eyes.

HMDs enhance users‟ feeling of immersion/interaction within a

world by excluding any glimpse of the real world and by revising

the view of the virtual world as the user move their head to look

around.



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• Desk-top.

The virtual world is projected onto the screen of a standard

computer monitor. This approach relies on interactive features

built into the world to provide a degree of immersion for users



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• Table-top

The virtual world is projected onto a horizontal table-top screen,

and is otherwise similar to the desk-top display. It allows

interaction in circumstances where a horizontal format is

appropriate. For example, a mechanic could learn how to fix a

virtual machine in a way that simulates working on a real table-

top.



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VIRTUAL REALITY DEVICES

Specialist hardware devices are available that can give users a

greater sense of immersion within the world. These devices include

the HMD and sensor or data-gloves, which are designed to allow

natural movements of the head or the hands in the real world to

control movements in a virtual world. However, the standard

computer keyboard, mouse, joystick or the more VR-specific

spaceball can enable a user to control a vehicle, avatar, tool or

viewpoint and offer a level of immersion within a virtual world.

Head Mounted Displays

Tiny displays, mounted in a helmet, suspended one in front of each

eye (in opaque HMDs), or projecting onto half-silvered mirrors in

front of each eye (in see-through HMDs)

Projection-Based Systems

A system in which the user is surrounded by images, projected onto

large screens. The prototypical example is the CAVE , developed by

Carolina Cruz-Neira et al. at the University of Illinois, Chicago, and

presented at SIGGRAPH in 1993.



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Comparison of HMDs and IPDs

IPDs offer:

1) A wide, surrounding field of view.

2) The ability to provide a shared experience to a small group

but, only one person (or none) in the group will be tracked

(1999) [now (2004), there are possibilities to track two

people].

Principal disadvantages of IPDs:

1) The cost of multiple image generation systems [now (2004),

this is not a serious limitation] space requirements for rear

projection [4-8 feet or more, depending on the size of the

screen]

2) Brightness limitations, due to large screen size [combined

with projector brightness limitations], which results in scenes

of approximately full-moon brightness, and hinders color

perception now (2004) companies like Christie Digital offerextremely high brightness projectors, such as the Mirage

10000 (10,000 lumens) but, these projectors, with native

stereoscopic capabilities, are extraordinarily expensive (MSRP

$150,000 each)

3) Corner and edge effects that intrude on displayed scenes [an

alternative: Dome systems, in which imagery is projected

onto a hemisphere surrounding the viewer(s)]

4) Reduced contrast and color saturation due to light scattering,

especially from opposing screens [this problem seems

inherent in the geometry; may be ameliorated by careful

choice of screen material.]



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Panoramic Displays

One or more screens arranged in a panoramic configuration; or a

single, curved screen, on which images from multiple projectors are

tiled together [issues: edge blending, on-the-fly color calibration,

viewpoint-dependent distortion correction, viewpoint-dependent

gain correction]

Workbenches

Flat, rear-projection screens that display images in stereo, and can

be set up in a horizontal or tilted position.

Boom

Developed by Fakespace a moveable, tracked stereoscopic display

that the viewer looks into.

Fishtank VR

A system in which images are displayed on a desktop monitor,

usually in stereo, and coupled to the location of the head, which is

tracked, resulting in the illusion of looking into a „fishtank‟. [stereo

is configured so that the displayed objects appear to be behind thescreen surface]



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Partially Immersive

The hardware that is used in these systems allows users to remain

aware of their real-world surroundings rather than being fully

immersed in the virtual world. For example, a partially immersive

system may include a sensor-glove and a virtual hand but use a

desk-top screen for visualisation. In this case, users are fully aware

of their surroundings but can interact with the world with natural

movements using the glove. Desk-top systems which allow users to

control movements using a standard mouse offer a lesser degree of

immersion

Data-Gloves



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APPLICATIONS OF VIRTUAL

REALITY

The most important thing in VR since 1994 is not the advances in

technologies, but the increasing adoption of its technologies and

techniques to increase productivity, improve team communication,

and reduce costs.

VR is now really real.Virtual reality has been described as a

'multidisciplinary effort covering everything from mechanical

engineering to psychophysiology'.Some of the more obvious applications of VR are those where a

computer permits simulations of the real world in a safe, controlled

or more economical environment.

• Demonstration



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• Pilot production - has real users but remains in the

developers‟ hands, under test

• Production - has real users doing real work, with the systemin the users‟ hands.



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• Vehicle simulation - vehicle crash testing or wind-tunnel

experiments

• Entertainment —virtual sets, virtual rides.



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• Vehicle design —ergonomics, styling, engineering

• Training - National Aeronautics and Space Administration,

vehicle, surgery etc.

• Medicine - psychiatric treatment.



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ADVANTAGES OF VIRTUAL

REALITY

It is cheaper, safer, and more efficient to train in a simulator than in

a real aircraft or ship; with VR, it is possible to simulate emergency

scenarios. Great gains were found in the effects on the design

process. In the ability to more efficiently and effectively

communicate ideas.

It is more useful in training and experience.

Examples: Astronaut training at NASA Psychiatric treatment atGeorgia Tech-Emory.

• Fear of flying.

• Fear of heights.

• Fear of public speaking.

• Post-traumatic stress disorders.

• Fear of spiders.

For NASA, it offers the ability to simulate alternative physics. For

psychiatry, it can save money, and offers a „safe‟ form of exposure

to traumatic stimuli.

What aspects of the VR make it work so well?

• Immersion is complete (or nearly complete).

• The near-field haptics are perfect.

What aspects of the VR are critical to success?

• Realism of the graphics.

• Realism of the sound.

• Realism of the haptics.

• Realism of the motion.

• Realism of the interaction. (how the displays respond to

user’s actions)

• True scale.



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DISADVANTAGE OF VIRTUAL

REALITY

Of course, Virtual Reality has some disadvantages as well. First,

there is the cost: A Virtually Reality devices sells for more than

$6,000 and requires a monthly licensing fee. That price tag doesn't

put it out of reach for most users, but it is a significant investment.

Also, the medicinal therapy does not work for everyone--and it

works better for some people than for others. Some studies havefound, for example, that people who are more hypnotizable or more

easily able to block out distraction and be absorbed in an activity

like reading are also more likely to benefit from virtual reality

exposure therapy.

Some of principle disadvantages are.

• System latency.

• The farther the design gets from its originator, the better the

visuals need to be, in order to enable the viewer to get an

accurate, internalized perception of the design.



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RECOMMENDATION

Our research on VIRTUAL REALITY has revealed many hot

and open challenges in this ever growing field.

Technological:

• Lowering latency.

• Rendering massive models in real time.

• Choosing which display best fits each application (HMD,

CAVE, panorama, bench).

• Producing satisfactory haptic augmentation for VR

illusions.

Systems

• Interactive more effectively with virtual worlds:

• Manipulation• Specifying travel

• Wayfinding

• Making model worlds efficiently

• Modeling the existing world

• Modeling non-existing worlds

• Measuring the illusion of presence and its operational

effectiveness.



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BIBLIOGRAPHY

We are really thankful to:

• http://www.google.com

• http://www.wikipedia.com

• www-vrl.umich.edu/intro/index.html

• www.vrealities.com/

• www.activeworlds.com/

• www.worldviz.com

• www.sciencedaily.com/news/computers_math/virtual_reality/

• http://www.lectlaw.com/files/lit04.htm

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