1. Lecture1. Introduction to Virtual Reality CSE 425 Spring 2002
김 창 헌
Department of Computer Science
Korea University
cgvr.korea.ac.kr

2. Contents What is VR? Conceptual Model of VR VR Related Areas History
State of the Art and R&D Issues
Some Application Examples
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3. Computational Reality
Glove  CG Machine  HMD : This is not VR!
Studies on reality - computational reality
VR = computational reality
1) Seek for the computational model of reality
2) Apply the model to the VR system
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4. Science vs. Engineering
Analogous to AI
lots of hypes
AI as a science / engineering
science - computational model for intelligence
engineering - making “intelligent-looking” machines
The essence of science is the search for models.
Greek scholars
stars, sky (heavenly bodies)  astrology
nature (earthly bodies)  physics
human mind  philosophy
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5. VR Concept
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6. What is VR? Definition -1
Def 1 - Computer generated environment that is ...
Immersive, (like IMAX, dome projection)
Interactive, (like computer game)
Multi-sensory,
Viewer-centered,
3D,
and the combination of technologies required to build such environments.
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7. What is VR? Definition -2
Def 2 - Physical participation in the interactive simulation.
Virtual environment
A computational model or realization of it by VR techniques.
Cyberspace
A computer environment spanning - multiple computers, multiple users, multiple sets of data.
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8. VR as a computer Technology
Ultimate computer interface : human body and its sensor  To turn the whole body into an input device
Technological trends
Powerful  Supercomputing, parallel computing
Smart  AI
Physical  VR
Primary concern - S/W Other important issues - H/W, human factors, social issues, infrastructure
VR computer - interactive, multimodal, immersive
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9. Interacting with computers
World
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10. New Paradigm for HCI Conventional Computer VR-based Computer Computer
World
Conventional Computer
Computer
World
VR-based Computer
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11. VR Application VR application Education/ Training Design Entertainment
Engineering
Medicine
Scientific
Visualization
Entertainment
Communication
Products
Museum
Arts
VR application
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12. All technologies meet together at VR !!
VR technologies
Character CRT
Graphic CRT
Virtual console
Virtual Reality
Tele-conference
TV phone
Telephone
Keyboard
Mouse tablet
3D mouse
Computer
simulation/
visualization
Tele-Existence
Tele-Operation
graphics
Real time CG
Video arts
3D CAD
Aided Design
Virtual
products
design
All technologies meet together at VR !!
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13. VR Terminologies VR in Real World vs. Virtual World Virtual Reality
Standard
Tele-Existence
Augmented
Tele-Existence in
Real World
Size
Sensation
Time
Virtual Reality
Physical World
Quasi Physical World
Non Physical World
Tele-Existence in
Virtual World
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14. Contents What is VR? Conceptual Model of VR VR Related Areas History
State of the Art and R&D Issues
Some Application Examples
cgvr.korea.ac.kr

15. Conceptual Model of VR Display system Computer Simulation System
3D image
Large-scale display, Head Mounted Display
Sound field by DSP
Force beedback mechanism
Tactile display
Display system
Computer
Simulation
System
Sensing system
Human
Non-contact type
magnetic field
supersonic wave
infrared light
Contact type
optical fiber
strain gauge
potentio-meter
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16. Contents What is VR? Conceptual Model of VR VR Related Areas History
State of the Art and R&D Issues
Some Application Examples
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17. VR Related areas 1. Training simulation 2. Tele-operation
3. Computer graphics
4. Artificial intelligence
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18. 1. Training simulation Example – Flight Simulation
Modern flight simulator is considered to be the most sophisticated application of a virtual environment.
This photograph depicts a state-of-art, Boeing 777, full-flight simulator with a 6 DOF motion platform, panoramic collimated display, 3D sound system and force feedback flight controls with the ability to take-off or land at any international airport in the world.
(Courtesy Thomson Training & Simulation Ltd)
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19. 1. Training simulation (cont) Training simulation
Differences
Reconfigurable by changing software
May include highly unnatural environment
Highly interactive and adaptive
Use of a wide variety of human sensing modalities and sensori-motor systems
Highly immersive
Near-field is synthetic Far-field is synthetic
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20. VR Related areas 1. Training simulation 2. Tele-operation
3. Computer graphics
4. Artificial intelligence
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21. 2. Tele-operation
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22. 2. Tele-operation (con’t)
for at least 30 years.
Tele-operator
- directly (manually) controlled tele-operator
- tele-robot
Tele-operation vs. Virtual reality
Tele-presence vs. Virtual presence
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23. 3. Computer graphics Modeling Motion control (animation) Rendering
User interface
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24. 4. Artificial intelligence
Studies on perception and cognition
Tested for AI research
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25. Contents What is VR? Conceptual Model of VR VR Related Areas History
State of the Art and R&D Issues
Some Application Examples
cgvr.korea.ac.kr

26. History 1’st stage: some visionaries
- Morton Heilig : ExperienceTheatre(1962)
- Ivan Surtherland : Sketchpad(1963), HMD(1966)
- Myron Krueger : Artificial Reality(1972)
- William Gibson : “Cyberspace” in Neuromancer(1984)
2’nd stage: technology development for specific purposes
- training simulator : Earlier works
- space exploration : NASA for astronaut simulation
- tele-operation
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27. History (cont) 3’rd stage: VR as the general-purpose technology
- Jaron Lanier : VPL(1987) – Dataglove, EyePhone,VR system
- VR industry : Division Ltd. Sense8, WorldDesign (production house, W-Industry (game)
- VR academia : MIT, UNC, UW,Tokyo U.
Next stage: Toward a scientific discipline
- computational reality
- a new computing paradigm
- a new media
- a new art form
- representation, creation and operation of virtual worlds
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28. Contents What is VR? Conceptual Model of VR VR Related Areas History
State of the Art and R&D Issues
Some Application Examples
cgvr.korea.ac.kr

29. State of the Art & Issues
State of the Art and R&D Issues
State of the Art & Issues
Reference
-Virtual Reality: Scientific and Technological Challenges”, pp , National Research Council, National Academic Press, 1995.
Areas of the study
1. application domains
2. psychological issues
3. VR technologies
4. evaluation of VR systems
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30. 1. Application domains design, manufacturing & marketing
medicine, health care
hazardous operations
training
entertainment, military
experimental psychology
education
information visualization
Tele-communication, Tele-travel
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31. 2. Psychological issues human performance characteristics
alteration of sensori-motor loops
developing the cognitive model
cognitive side-effect
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32. 3. VR technologies (1) Human-Computer Interface
Gap between the current technology & the required technology
(exception - entertainment, tele-operation)
(1) Human-Computer Interface
(2) Computer Generation of VE
(3) Tele-robotics
(4) Network
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33. State of the Art and R&D Issues (con’t)
1. Application Domains
2. Psycological issues
3. VR technologies
(1) HCI (Human-Computer Interface)
(2) Computer Generation of VE
(3) Tele-robotics
(4) Network
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34. (1) Human-Computer Interface
3. VR technologies
3D image
Large-scale display, Head Mounted Display
Sound field by DSP
Force beedback mechanism
Tactile display
Simulation
System
Computer
Display system
Sensing system
Non-contact type
magnetic field
supersonic wave
infrared light
Contact type
optical fiber
strain gauge
potentio-meter
Human
cgvr.korea.ac.kr

35. (1) Human-Computer Interface (con’t)
visual channel
auditory channel
haptic channel
motion interface
position tracking
video camera
microphone
others
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36. (1)HCI – Visual Channel visual display HMD (Head-Mounted Display)
OHD (Off-Head Display)
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37. (1)HCI – Visual Channel (con’t)
research issues
- ergonomics
- improvement of resolution and FOV (field of view)
- wireless
- integration of visual, auditory, position tracking
- sun glass-like
- see-through option
exploiting FOV and peripheral vision
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38. (1)HCI – Auditory channel
Current hardware is adequate.
Research issues
perceptual issues
similar to the visual channel
use for sensory substitution (for visual, haptic)
auditory scene analysis
hear-through display
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39. (1)HCI – Auditory channel (con’t)
Traditional Stereo Sound
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40. (1)HCI – Auditory channel (con’t)
3D virtual Sound
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41. (1)HCI – Haptic channel Force, Pressure, Tactile Feedback
Unique characteristics
Haptic interface requires manipulation and sensing
Mechanism
body-based  glove, exoskeleton
ground-based  joystick
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42. (1)HCI – Haptic channel (con’t)
Research issues
haptic science = study on the human haptics (bio-mechanical, psychophysical, cognitive)
tool-hand system (which takes its metaphor from real tools)
creating the haptic illusion
the interaction effects of haptic and vision
texture, temperature devices
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43. (1)HCI – Haptic channel (con’t)
Haptic channel in Tele-operation
Haptic devices
Operator module
Work side module
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44. (1)HCI – Haptic channel (con’t)
Interaction of haptic and vision
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45. (1)HCI – Motion interface
whole-body motion
passive - e.g., motion platform
active - e.g., locomotion
part-body motion
passive
active
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46. (1)HCI – Motion interface (con’t)
motion cues
vestibular system - inertial
motor
visual
auditory
proprioceptive / kinesthetic - muscle
tactile
Inertia 관성의
Proprioceptive 감각 수용기의
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47. (1)HCI – Motion interface (con’t)
inertial system
moves the body (e.g., treadmill, motion platform)
non-inertial system
simulates motion
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48. (1)HCI – Position tracking and mapping
Tracking = finding a point
Mapping = finding a 3D surface
(e.g., environmental mapping)
Tracking mechanisms
Mechanical linkage
Magnetic
Optical
Acoustic
Inertial
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49. (1)HCI – Position tracking and mapping (con’t)
eye tracking
research issues
tracking
mapping
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50. (1)HCI – Other types of interfaces
olfactory (smell)
gustatory (taste)
heat, wind, humidity
speech
direct physiological sensing and control
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51. State of the Art and R&D Issues
1. Application Domains
2. Psycological issues
3. VR technologies
(1) human-machine interface
(2) computer generation of VE
(3) tele-robotics
(4) Network
cgvr.korea.ac.kr

52. Conceptual Model of VR Display system Computer Simulation System
3D image
Large-scale display, Head Mounted Display
Sound field by DSP
Force beedback mechanism
Tactile display
Simulation
System
Computer
Display system
Sensing system
Non-contact type
magnetic field
supersonic wave
infrared light
Contact type
optical fiber
strain gauge
potentio-meter
Human
cgvr.korea.ac.kr

53. Generation of VE(cont’)
(2) Computer Generation of VE
Generation of VE(cont’)
The core issue
General-purpose VR system?
Trade-off between realism and interactivity
Requirements
frame rate
response time
scene quality
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54. Generation of VE(cont’)
(2) Computer Generation of VE
Generation of VE(cont’)
hardware
interaction and navigation
VE management
-simulation
-rendering
modeling
autonomous agent
hypermedia interaction OS
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55. VE management - simulation
Task : simulating everyday world
Traditional simulation methods do not work.
 requires pre-processing
Need : “meta-modeling”
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56. VE management – Rendering
Issue : load balancing
1. partitioning VE
2. LOD
Much work has been done on static scene.
Research issues
1. dynamic scene
2. parallel rendering
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57. (2) Computer Generation of VEOS
real-time, multi-modal requirements
very high-resolution time slicing
atomic, transparent distribution of tasks
large number of light-weighted processors, communicating by means of shared memory
support for time-critical computing:
negotiated, graceful degradation
guaranteed frame rate, lag time
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58. State of the Art and R&D Issues
1. Application Domains
2. Psycological issues
3. VR technologies
(1) human-machine interface
(2) computer generation of VE
(3) tele-robotics
(4) Network
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59. (3) Tele-robotics Tele-robotics and VR Hardware Time-delay problem
Distributed Tele-robots
Operator - stays in a safe environment - guides the robot intelligently
Robot - works in the hazardous environment
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60. (4) Network The future is here! Applications current future
distance learning
group entertainment
distributed training
distributed design
current
future
What is needed
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61. Research Organizations
International Efforts
U.S.A. defense, space, visualization, medicine
U.K. education, training, entertainment
Germany
Japan VR as a logical extension of robotics, automation, HDTV.
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62. Academia HIT Lab, University of Washington
University of North Carolina
Media Lab, MIT
Georgia Institute of Technology
Naval Postgraduate School
University of Pennsylvania
University of California at Berkeley
University of Illinois - Chicago
Columbia University
University of Toronto
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