virtual reality service

8/9/2019 Virtual Reality Service

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WHAT IS VIRTUAL REALITY?

Virtual reality (VR) is a computer-simulatedenvironment, whether that environment is a simulation

of the real world or an imaginary world.

Most current virtual reality environments are primarilyvisual experiences, displayed either on a screenerthrough special or stereoscopic displays, but somesimulations include additional sensory information,such as sound through speakers or headphones.


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Three Key Elements inThree Key Elements in

ExperiencingExperiencing VRVRA virtual environmentA virtual environment

Diving (physical and mental) gives a sense of "presence" in the virtualDiving (physical and mental) gives a sense of "presence" in the virtual

environment, this can be a purely mental state or realized by physicalenvironment, this can be a purely mental state or realized by physicalmeansmeans

Feedback:Feedback:Sensory visual / auditory / tactile / ... sent to the user.Sensory visual / auditory / tactile / ... sent to the user.

Interactivity:Interactivity:An experience of virtual reality, participants can move and changeAn experience of virtual reality, participants can move and change

perspectiveperspective


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ComponentsComponents of Immersive VRof Immersive VR

Immersive VR: A human user placed in a virtual

environment


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Typical Components of VRTypical Components of VR

Base System:Base System:ComputerComputer

HeadHead--Mounted Display (HMD)Mounted Display (HMD)HandHand--tracked device (VR Glove or Wand)tracked device (VR Glove or Wand)

3D graphics rendering system3D graphics rendering system

3D sound, space ball, etc.3D sound, space ball, etc.


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Typical Computer used for VRTypical Computer used for VR

SGIs Onyx 2 (4 CPUs, 2

Infinite Reality Pipelines)

The SGI Onyx2, code name

Kego, is a family of

visualization systems

developed andmanufactured by SGI,


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HEADHEAD MOUNTEDDISPLAYMOUNTEDDISPLAY

Small displays mounted on the

head completely immersive, they

need a tracker to track theposition and orientation of the

head


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Stereoscopy

Stereoscopy is a technique that creates the illusion

of depth 'in an image.

The illusion of depth 'in a photograph, film or other

2D and' created by two slightly different images for

each eye.


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3D Tracking Paradigm

One or more sensors determine the position andOne or more sensors determine the position andorientation in relation to a sourceorientation in relation to a source

The sensor (s) receives a signal from the source andThe sensor (s) receives a signal from the source andprovides both position and orientationprovides both position and orientation

Source and sensor can be fixed or mobileSource and sensor can be fixed or mobile

DiverseDiverse technologies: Ultrasonic, Electromagnetic,technologies: Ultrasonic, Electromagnetic,OpticalOptical


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Localization by Ultrasound

A source (issuer) issues a signal (ultrasound)

to the glove, which contains 2-3 receivers

The time that elapses between the emission and

reception determines the distance between

sender-receiver


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Localization by UltrasoundLocalization by Ultrasound

Emitter

Ultra sound wave

Finger flexion sensor

Spatial sensorposition


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Ultrasonic Tracking AdvantagesUltrasonic Tracking Advantages

andand DisadvantagesDisadvantagesBenefitsBenefits

Low CostLow Cost

Easy to implementEasy to implement

No obstacles between transmitter and receiverNo obstacles between transmitter and receiver

Disadvantages

Very short range (Few Feet)

Strongly dependent on temperature and air humidity


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Localization by Electromagnetic (EM) PulsesLocalization by Electromagnetic (EM) Pulses

Three antennas emit radio pulses in sequence

Three antennas receive pulses and determine

the signal strength along the axes

The global power of the three antennas give the

distance from the source station


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Localization by EM PulsesLocalization by EM Pulses

Receiverweak signal

Emitter

strong

signal


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EM Advantages andEM Advantages and

DisadvantagesDisadvantages

AdvantagesAdvantages

Facilities management trackingF

acilities management tracking There may be barriers between source and sensorThere may be barriers between source and sensor

Mature technologyMature technology

DisadvantagesDisadvantages Errors in trackingErrors in tracking

Short rangeShort range

Highly sensitive magnetic materials and metal objects inHighly sensitive magnetic materials and metal objects inenvironmentenvironment


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Localization by OpticalLocalization by Optical

CorrelationCorrelation Stereoscopic analysis, correlation pixels to twoStereoscopic analysis, correlation pixels to two

images from two camerasimages from two cameras

Items allow the triangulation of the positionsItems allow the triangulation of the positions(3D)(3D)

The triangulation is based on the correspondenceThe triangulation is based on the correspondenceof similar points on two different images takenof similar points on two different images taken


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Localization by OpticalLocalization by Optical

CorrelationCorrelation


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Optical Advantages and DisadvantagesOptical Advantages and Disadvantages

AdvantagesAdvantages

Very good quality signal trackingVery good quality signal tracking

One of the most accurateOne of the most accurate

No obstacles between transmitter and receiverNo obstacles between transmitter and receiver

DisadvantagesDisadvantages

Difficult to achieveDifficult to achieve


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Cave Automatic Virtual Environment (CAVE)Cave Automatic Virtual Environment (CAVE)

The CAVE is a largeThe CAVE is a large

theatre that sits in a largertheatre that sits in a larger

room measured a variedroom measured a varied

size. The walls of thesize. The walls of the

CAVE are made up ofCAVE are made up of

rearrear--projection screens,projection screens,

and the floor is made of aand the floor is made of adowndown--projection screen.projection screen. A virtual reality CAVE display

projecting images on to the floor,

walls and ceiling to provide full

immersion


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CAVECAVE

Completely immersiveCompletely immersive

Maximum cost solutionMaximum cost solution

Centralized facilityCentralized facility

Not MobileNot Mobile

Goals that inspiredC

AVEEngineering

1. The desire for higher-resolution color

images and good surround vision without

geometric distortion

2. Less sensitivity to head-rotation inducederrors

3. The ability to mix virtual reality imagery

with real devices (like one's hand, for

instance)

4. The need to guide and teach others in a

reasonable way in artificial worlds


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Cave Applications

architectural walkarchitectural walk--throughthrough

evaluation of engineering designs (virtual prototyping)evaluation of engineering designs (virtual prototyping)

driving simulatorsdriving simulators

training for dangerous situations and other scenariostraining for dangerous situations and other scenarios molecular modelingmolecular modeling

virtual reconstruction of archeological sitesvirtual reconstruction of archeological sites

medical and biological visualizationmedical and biological visualization

artistic expression of ideas, and more ...artistic expression of ideas, and more ...


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Cave ApplicationsCave Applications


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Applications of VRApplications of VR

simulationsimulation

games, military, traininggames, military, training

VR holidaysVR holidays

rainforest, safari, surf, ski and moon walkrainforest, safari, surf, ski and moon walk all from your own armchair all from your own armchair

medicalmedical

surgerysurgery scans and xscans and x--rays used to build modelrays used to build model

then practice operationthen practice operation force feedback bestforce feedback best

phobia treatmentphobia treatment

virtual lifts, spiders, etc.virtual lifts, spiders, etc.


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IMPORTANCEIMPORTANCE OF VIRTUAL REALITYOF VIRTUAL REALITY ININ

SURGICAL FIELDSURGICAL FIELD

The main advantages of virtual reality in surgery are:The main advantages of virtual reality in surgery are:

Intelligent computer backup minimizes the number of mistakes.Intelligent computer backup minimizes the number of mistakes.

More effective use of minimalMore effective use of minimal--access surgical technique, which reducesaccess surgical technique, which reducesthe long length of hospital stays and rest of postoperativethe long length of hospital stays and rest of postoperativecomplications.complications.

Better training in anatomy and surgical skill, with reduced need forBetter training in anatomy and surgical skill, with reduced need forcadavers.cadavers.


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AugmentedAugmented Reality (AR)Reality (AR)

Unlike virtual reality, augmented reality refers to situations in which theUnlike virtual reality, augmented reality refers to situations in which theaim is to integrate the user's perception of the real world by adding virtualaim is to integrate the user's perception of the real world by adding virtualobjectsobjects

AR and 'technology or an environment where the additional informationAR and 'technology or an environment where the additional informationgenerated by a computer, and' inserted in the user view a scene of realgenerated by a computer, and' inserted in the user view a scene of realworldworld

AR are two main category of HMD-basedAR systems often make use ofhead mounted displays (HMD)

Other systems:OpticalSee-ThroughAugmented RealityVideo-basedAugmented Reality


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What is Augmented Reality?What is Augmented Reality?

A combination of a real scene viewedA combination of a real scene viewedby a user and a virtual scene generatedby a user and a virtual scene generatedby a computer that augments the sceneby a computer that augments the scenewith additional information.with additional information.

Create a system such that no userCreate a system such that no userCANNOT tell the difference betweenCANNOT tell the difference between

the real world and the virtualthe real world and the virtualaugmentation of it is the ultimate goalaugmentation of it is the ultimate goalof augmented realityof augmented reality


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Augmented Reality v/s Virtual Reality

Augmented RealityAugmented Reality

System augments the realSystem augments the realworld sceneworld scene

User maintains a sense ofUser maintains a sense ofpresence in real worldpresence in real world

Needs a mechanism toNeeds a mechanism to

combine virtual and realcombine virtual and realworldsworlds

Virtual Reality:Virtual Reality:

Totally immersive environmentTotally immersive environment

Visual senses are under control ofVisual senses are under control ofsystem (sometimes aural andsystem (sometimes aural andperceptive senses too)perceptive senses too)


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Optical seeOptical see--throughthrough

Partially transparent optical combiners arePartially transparent optical combiners are

placed in front of the eyes, let them seeplaced in front of the eyes, let them seethe reflection of virtual imagesthe reflection of virtual imagesrepresented on a small displayrepresented on a small display

ADVANTAGE :

Simplicity

Resolution

No eye offset


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VideoVideo--basedbased

It uses small video cameras to

capture the vision of the real world

that would be seen through the

eyes. The real images are combined

with virtual ones, created by the

computer to create id in the ImageAR that appear on a typical HMD

ADVANTAGE: Flexibility in

composition strategies

Wide field of view

Real and virtual view delays can be

matched


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ApplicationsApplications

MedicalMedical

EntertainmentEntertainment

MilitaryT

rainingMilitaryT

raining Engineering DesignEngineering Design

Robotics andTeleRobotics andTele

roboticsrobotics

Manufacturing,Manufacturing,

Maintenance, andMaintenance, and

RepairRepair

Consumer DesignConsumer Design

Hazard DetectionHazard Detection

AudioAudio


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A

RA

R--based Videoconferencingbased Videoconferencing


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A

V-based videoconferencing


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