CHAPTER 14

INTRODUCTION TO VIRTUAL REALITY

T.J.Iskandar Abd AzizAdapted from Notes Prepared by:Noor Fardela Zainal AbidinRevised on Sept 2012

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CGMB113/ CITB 123: MULTIMEDIA TECHNOLOGY

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Objectives

At the end of this chapter, students should be able to:

• identify the terms and concept related to virtual reality

• describe the two approaches in Virtual Reality• describe the different types of Virtual Reality • understand how virtual reality can be applied in

everyday life

What is VR?3

Virtual reality (VR) refers to a set of techniques for creating synthetic, computer-generated environments in which human operators can become immersed.

Virtual Reality is a way for humans to visualize, manipulate and interact with computers and extremely complex data

What is VR4

"Virtual Reality (VR) is a technology that makes use of 3D graphics, simulation, and special interfacing devices .

VR is about using computers to create images of 3D scenes with which one can navigate and interact.

What is VR5

Virtual Reality is 3D computer Simulation Providing sensations (sight, sound, touch,

force feedback etc) Making you feel you are really in a “place”

Virtual Environment6

Virtual Environment or VE is Real-time simulation of real or imagined environment Experienced at least visually VE Supports navigation through VE Supports 3D pointing Supports interaction with dynamic scene elements.

Virtual Environment 7

Telepresence Experience of being present at virtual site

Immersion Sense of being surrounded by sensory experience

Virtual World Is large and unbounded VE with background like sky

Approach in VR8

1. Realist Approach2. Constructivist Approach

1) Realist Approach9

Uses VR as Recapitulation of Reality Means of making realities of situation manifest Medium for exploring possible realities

Example Computer aided design: living space design Distance learning: remote presentation Simulation: re-enactment of accident Training: flight simulators Modeling: Geographic information systems

2) Constructive Approach10

Use VR as Artificial construct Means of social interaction and cultural

expression Medium to be understood using theatre and film

conceptsExample

Creative Expression – Cyber Art Fantasy Gaming – Sim City, Quake Intellectual Aid – Information Visualisation Social Encounters - Cybermalls

Types of VR11

1. Window on World Systems (WoW)

2. Video Mapping 3. Immersive Systems 4. Telepresence 5. Mixed Reality

Types of VR12

Window on World Systems (WoW)

Some systems use a conventional computer monitor to display the visual world. This sometimes called Desktop VR or a Window on a World (WoW).

Quote "One must look at a display screen," he said, "as a window through which one beholds a virtual world.

The challenge to computer graphics is to make the picture in the window look real, sound real and the objects act real."

Types of VR13

Video Mapping A variation of the WoW approach

merges a video input of the user's silhouette with a 2D computer graphic.

The user watches a monitor that shows his body's interaction with the world.

Types of VR14

Immersive Systems

The ultimate VR systems completely immerse the user's personal viewpoint

inside the virtual world.

These "immersive" VR systems are often equipped with a Head Mounted

Display (HMD).

This is a helmet or a face mask that holds the visual and auditory displays.

The helmet may be free ranging, tethered, or it might be attached to some

sort of a boom armature.

A nice variation of the immersive systems use multiple large projection

displays to create a 'Cave' or room in which the viewer(s) stand.

The Holodeck used in the television series "Star Trek: The Next Generation" is

afar term extrapolation of this technology.

Types of VR15

Telepresence Telepresence is a variation on visualizing

complete computer generated worlds. This a technology links remote sensors in the real world

with the senses of a human operator. Fire fighters use remotely operated vehicles to handle

some dangerous conditions. Surgeons are using very small instruments on cables to do

surgery without cutting a major hole in their patients. Robots equipped with telepresence systems have already

changed the way deep sea and volcanic exploration is done. NASA plans to use telerobotics for space exploration.

Types of VR16

Mixed Reality Merging the Telepresence and Virtual Reality systems

gives the Mixed Reality or Seamless Simulation systems.

Here the computer generated inputs are merged with telepresence inputs and/or the users view of the real world.

A surgeon's view of a brain surgery is overlaid with images from earlier CAT scans and real-time ultrasound.

A fighter pilot sees computer generated maps and data displays inside his fancy helmet visor or on cockpit displays.

VR Advantages17

Better Communication. Enabling faster completion of projects

Presentation are usable for difference purposes

Able to view aspect that would either wise never show up or to late.

Usually more affordable than building a scale model or mock up.

Cost effective and safer. Ex: flight simulation

VR Dis-advantages18

VR world is visually unconvincing because there are sometimes low resolution, have limited field of view and exhibit noticeable head motion lags

VR world lack realism and cartoonishVR can make you sick because of motion

tracking and conflict in visual display VR is expensive to createDependent on rare and specialized display

devisesRequire special computing hardware.

VR TECHNOLOGY

Prepared by:Noor Fardela Zainal Abidin© UNITEN 2004/2005

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CITB 123: MULTIMEDIA TECHNOLOGY

BOOM Display20

Binocular Omni-Orientation MonitorPuts high resolution stereo display on

counterbalance arm.Is moves by hand grips or attached to user’s

headProvides accurate head trackingIs only single user experienceTethers and restricts range of movements

BOOM Display

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Desktop VR22

Provides VE display on desktop monitorUsually is not head trackingIs cheaper and accessibleIs not immersive (field of view limited)Is not encumberingReally enquires 3D pointer for interaction

Desktop VR23

Desktop VR can be delivered in a variety of modes Stereo to screen shutter glasses Stereo to polarized screen overlay and polarized

glasses Non stereo output to immersive wide screen display.

Desktop VR24

Goggles and Gloves25

Impressively integrates Stereoscopic viewing via LCD display Head and hand tracking Finger flexion input from data gloves

Is only single user experienceLimits corporal presence in VE to handSuffers from high latency & limited accuracy of

trackingIs encumbering: tethers user by wire or by IR

comms rangeHas health hazard: bumping & cybersickness

Goggles and Gloves

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VIRTUAL ROOM27

Cave Automatic Virtual Environment Is 10-foot-square room composed of projection

screens Use projectors to project stereo images on 3

walls & floor Gives perspective control to user with e-m

tracker & wand CAVE was 1st developed in 1991 at Electronic

Visualization Label Cave s unencumbering Sharable expensive

VIRTUAL ROOM28

HMD

Head Mounted Device Is any device which

literally mount on the head and displays an image viewable only by the wearer of the device.

It is used for a wide variety of commercial, industrial, medical and personal applications.

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INPUT DEVICES30

Mechanical Input Devices Boom trackers, feedback mice, joysticks, steering

wheel.

Electromagnetic Input Devices Transmitter generates magnetic field in 3

orthogonal coils Receiver picks up field emission Sensors are small and may be attached o body,

stylus, glove etc.

INPUT DEVICES31

Optical Input Devices Light sources tracked by sensors Either sources or sensors are mounted on tracked

objects Infra-red’s lack of visibility does not distract

Acoustic Input Devices Microphones received ultra-sound pulses sent by

emitters

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MSC – Virtual Reality Center

http://cmc.msc.com.my/

Reference33

Funding  A Revolution Government Support for Computing Research. Copyright 1999 National Academy Press http://www.nap.edu/readingroom/books/far/contents.html

http://www.isdale.com/jerry/VR/WhatIsVR/noframes/WhatIsVR4.1-VR.html

Hamish Taylor, lecture Notes Multimedia technology 12.5G2, Heriot-Watt University Scotland.