Computer Graphics 2

In the name of God

Outline

• Introduction1. References2. Evaluation• |Introduction to Virtual Reality• History of Virtual Reality• Application • Virtual reality and virtual Environment• VR devices• Some example

References(1)• J. D. Foley, A.Van Dom, S. K. Feiner, J. F. Hughes,

Computer Graphics Principle and practice, Addison Wesley

, 1994.

• J. D. Foley, A.Van Dom, S. K. Feiner, J. F. Hughes, R.Philips, Introduction to computer Graphics, Addison Wesely,1990.

References(2)1. M. Maentylat, Solid Modeling, Computer Science press, Rockville

, 1988.

2. D.Roger and J.A. Adams, Mathematical Elements For Computer

Graphics, Mc Graw Hill 1979,New York.

3. A. Watt, M.Watt , Advanced Animation and Rendering Techniques,

Theory and Practice, Addison Wesley Publishing Company, 1994.

4. J. White, Designing 3D Graphics: How to create Real time 3D

Models For Games and Virtual Reality, John Wiley and sons.5. J. D. Foley, A.Van Dom, S. K. Feiner, J. F. Hughes, Computer Graphics Principle and practice C Version), Addison Wesley Publishing Company, 1996.

Evaluation

Midterm & Attendance 5 Marks

Final Exam 10 Marks

Programming Assignment 5 Marks

(Below 6 on the final exam means students have failed the

course, despite full marks on midterm and programming

assignment.)

Aims

• Introduce basic graphics concepts and terminology

• Base for development computer graphics programmes

OpenGL

C Programming Liner Algebra

Introduction

Virtual reality

Computer graphics(Photo realistic rendering,

Non photo realistic rendering)

Image processing

image

Interactive Computer Graphics

User

Application

Screen

input

image

VR Overview

• VR one of hottest research and development areas in computer industry today.

• VR not new technology, development dates back almost 50 years (first flight simulators during World War II).

• Potential applications: from medical imaging and interior design to intercontinental videoconferencing and

exploration of future worlds.

• VR often thought of as new technology, but development dates back almost 50 years to flight simulators built by aircraft industry and U.S. Air Force during and after World War II.

Triangle of Virtual Reality

Immersion

Real time

Interaction

• Immersion : Feeling to be in the 3D Virtual Space.

• Interaction :Possibility of moving in the 3D space and manipulate objects

• Real Time : Actions can immediately modify the state of the space .

History of Virtual Reality(1)

• Student pilots learned how to manoeuvre airplanes by manipulating controls in specially built airplane cockpits, removed from airplanes themselves, and mounted on movable platforms that tilted and rolled based on pilot's actions on controls.

• VR's future also influenced by film techniques in cinema, and several wide-screen systems that Hollywood filmmakers were experimenting with during the early 1950's.

First Link Simulator 1929

History of Virtual Reality(2)

• CINERAMA Cinerama, best-known of these technologies

by filling a larger portion of audience's visual field.

• 3 cameras, shooting from slightly different angles, used to film each scene in Cinerama movie.

• Film then synchronized and projected onto 3 large screens that curved inward, wrapping around audience's peripheral visual field.

• Technology proved too costly to be embraced by most commercial theaters, but theory of visual immersion becomes an important VR element ?

History of Virtual Reality(4)

• In the 1960s Raymond Goertz at Argonne National Laboratory in Argonne, Illinois demonstrated early versions of HMDs.

• Displaying images from remote, closed-circuit cameras, these were used for viewing inside "hot cells" where radioactive materials were handled experimentally or processed in small batches for use in nuclear power and medicine.

History of Virtual Reality(3)

Sensorama• in 1962, Sensorama: simulation of sensory

experiences of a motorcycle ride by combining 3D movies, stereo sound, wind, and aromas.

History of Virtual Reality(5)

The Aspen Movie Map developed by group of researchers including ScottFisher at MIT• showed video images of Aspen,Colorado• visitors could actually navigateby indicating their choices ontouch-sensitive display screen

History of Virtual Reality(6)

NASA• Mid-1980's: different technologies convergedto create first true VR system.

• Researchers at NASA' s Ames Research Centercharged with creating affordable pilot trainingsystem for manned space missions.

• People involved: Scott Fisher, Stephen Ellis,Michael McGreevy, and Warren Robinett.

• efforts led to development of Virtual InterfaceEnvironment Workstation.

• first system combined such standard VRelements as computer graphics and videoimaging, sound, voice recognition andsynthesis, and HMD.

History of Virtual Reality(7)

NASA (2)• data glove, based on invention designed to play air guitar, completed the system.

• 1984: Mike McGreevy and JimHumphries originators of VIVED(VIrtual Visual Environment Display).

• They evaluated potential ofmonochrome HMD system for futureastronauts.

• Later, VIEW (Virtual InteractiveEnvironment Workstation) projectdeveloped general-purpose,multi_sensory, personal simulator andtelepresence device.

VIVED

History of Virtual Reality(5)

Today• In recent years, VR devices have improved dramatically as result of various technological advances.

• Computers more powerful, higher memory capacity, smaller, and cost less than in the past.

• These developments + advent of small LCDdisplays that can be used in HMDs, have made it possible for scientists to develop VR simulations.

Flight simulators(1)

• Development of flight simulators hasmade very significant contributionsto development of VR.

• Much of technology needed for VRdeveloped for military flightsimulators.

• Advanced fighter cockpit wherefighter pilot wore HMD thataugmented out window view withgraphics.

• Graphics included identification, targeting information, threat information (e.g. ground based missile sites) and optimal flight path information

Flight simulators(2)

Cockpits real with theirinstruments, joysticks, levers,switches, buttons, sliders.

• Each instrument possessindividual mechanicalcharacteristics.

• Pilots constrained tofloor-mounted chairs, and duringtake-off and landing scenarios,restrained by seat belts.

• It would be ridiculous to build allinstruments and chairs in virtualworld.

Flight simulators(3)•fighter pilot operating under extremely high stress levels (both cognitive and physical), yet has to process masses of data.

• Unfortunately, commercial flight simulators cost millions of dollars each.

• For VR, we must achieve similar exactness at a tiny fraction of the cost.

Introduction to Virtual Environment

• A technology which is capable of shifting a subject into a different environment without physically moving him/her.

• the subject's sensory organs are manipulated in perceived environment is associated with the desired Virtual Environment (VE) and not with the physical one.

• The manipulation process is controlled by a computer model based on the physical description of the VE.

Virtual Reality (VR) & Virtual Environments (VEs)

• VR known as a new dimension in man-machine communication that combines real-time computer graphics and direct interaction in 3D space.

• VEs must improve man machine communication

• VEs should allow better and faster understanding of even complex applications and provide means for operations and control.

CAVE

The CAVE is a surround-screen, surround sound, projection-based VR system.

• The illusion of immersion is created byprojecting 3D computer graphics into a3mx3mx2.7m cube composed of displayscreens that completely surround theviewer.

• It is coupled with head and hand tracking systems.

• A sound system provides audio feedback.

Virtual Reality(1)

• The term "immersion" is a description of a technology, which can be achieved to varying degrees.

• For example, a head-mounted display with wide field of view, and at least head tracking would be essential.

• The degree of immersion is increased by adding additional, and consistent modalities, greater degree of body tracking, richer body representations, decreased lag between body movements and resulting changes in sensory data, and so on.

Virtual Reality(2)

• immersion as the feeling of a VR user, that his VE is real.

• Analogously to Turing's definition of artificial intelligence: if the user cannot tell, which reality is "real", and which one is "virtual", then the computer generated one is immersive.

• A high degree of immersion is equivalent to a realistic VE.

Virtual Reality(3)

• Presence is the psychological sense of "being there" in the environment based on the technologically founded immersive base.

• However, any given immersive system does not necessarily always lead presence for all people.

Virtual Reality Devices(1)

• Hand measurement devices must sense both the flexing angles of the fingers and the position and orientation of the wrist in real-time.

• The first commercial hand measurement device was the DataGlove from VPL Research.

• The DataGlove consists of a lightweight nylon glove with optical sensors mounted along the fingers.

Virtual Reality Devices(2)

• VR devices

Cyber Grasp

Virtual Reality Devices(3)

• 3D Mouse and SpaceBall• Some people have tried to extend the

concept of the mouse to 3-D.

• These are used to track the receiver position, orientation and movement. It provides proportional output in all 6 degrees of freedom: X, Y, Z, Pitch, Yaw, and Roll.

Virtual Reality Devices(4)

• SpaceBall®

2. Logitech 3D mouse

1. Space Ball

Virtual Reality Devices(5)

• VR devices

Use of CyberTouch

Head Mounted Diplay

VR Example(1)

VR Example(2)

Virtual Reality Applications

• VR may offer enormous benefits to many different applications areas.

• One main reason why it has attracted so much interest.

• VR currently used to explore and manipulate experimental data in ways that were not possible before.

Examples

Vehicle Simulation for Security

VR for Psychotherapy

•With advent of realistic virtual humans, possible to recreate situations in VE, immersing real patient into virtual scenes,

•

Fear of heights (acrophobia)

One of the very common phobias is thefear of heights.

• People are having extreme reactions onthe very notion of heights.

• Whereas in the real world it is difficultto control the surrounding and theheight the patient is exposed to, VRenables a therapist and a patient toachieve the complete control of thevirtual world.

Fear of spiders (arachnophobia)

created at the University of Washington

• After identifying a phobic patient,Spider World was created by placing virtualspiders in the virtual kitchen.

• Prior to treatment, the patient had beenclinically phobic for nearly 20 years and hadacquired a number of spider-related obsessive compulsive behaviors.

• During VR therapy, the patient was sometimesencouraged to pick up the virtual spider and/orweb with her cyber hand and place it inorientations that were most anxiety provoking.