Virtual Reality (VR) What is Virtual Reality? - PCU ?? You can experience a virtual ... – The retinal display ... Introduction to Virtual Reality References • Understanding Virtual Reality, ...

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  • - 1 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    Virtual Reality (VR)

    Ivan Sutherland about computer generated illusion:The screen is a window through which one sees a virtual world. The challenge is to make that world look real, act real, sound real, feel reel.

    Questions:1. What is VR now?2. What might it become?3. What technology problems

    need to be solved?

    June 6, 2003

    - 2 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    What is Virtual Reality?

    A medium composed of interactive computer simulations giving users the feeling of being present in the simulations.

    Virtual Reality is a way for humans to visualize, manipulate and interact with computers and extremely complex data - The Silicon Mirage: The Art and Science of Virtual Reality.

    Virtual reality is an artificial world generated by a computer. Participants can observe the world and interact with the simulated environment.

    Many of the experts in the field consider the description Virtual Reality to be inappropriate. Virtual Environments (VE) is thought to be a more accurate description.

    An immersive interactive system VR is about Fooling the mind

    - 3 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    Key Elements

    Real-time graphics framerate: 30 frames/sec polygons: 50K/frame (more would be nice) resolution: as much as you can get

    Low latency time lag between sensing a change and updating the picture 1 ms latency => 1 mm error (at common head/hand speed)

    Interactive manipulation possible? response times

    Multi-sensory vision sound force feedback

    Real-time graphics:- You do it really fast- You do it slightly slower- You do it ok- You do it badly

    Real-time programming:- You do it = you succeed- You dont do it

    - 4 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    Applications

    architectural walkthroughs rapid prototyping data visualization medical modeling weather simulations sound simulations traffic simulations true 3D user interfaces high risk job training entertainment flight simulation teleoperation of robots communication (virtual meetings)

    VR Systems were not developed to meet aspecific need; they were developed becausethey were possible - John Vince

  • - 5 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    History (very incomplete)

    1957 Morton Heilig invented the Stereoscopic TV

    Apparatus for Individual Use. (Patented 1960) 1960

    The Boeing Corporation coined the term computer graphics.

    1963 Ivan Sutherland submitted his doctoral thesis

    SKETCHPAD: A man-machine graphical communication system.

    1965 Ivan Sutherland published The Ultimate Display.

    1968 Ivan Sutherland published A Head-mounted Three

    Dimensional Display. 1989

    Jaron Lainer coined the term virtual reality. 1993

    SGI announced the Reality Engine.

    - 6 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    VR Systems

    VR Systems can be divided intothree groups

    non-immersive systems (like workstations) immersive systems (like HMD or CAVE) hybrid systems (graphics on top of real world)

    also called: augmented reality systems

    The following conditions are important to experience full immersion:

    Full field of vision display, usually produced by the wearing of a Head Mounted Display.

    Tracking of the position and attitude of the participant's body.

    Computer tracking of the participant's movements and actions.

    Negligible delay in updating the display with feedback from the body's movements and actions.

    - 7 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    A Generic VR System

    Physical simulationand animation

    Illumination model

    Objects (geometry& other properties)

    Collision detection

    visual

    audio

    haptic

    hand position

    head position

    Inputs OutputsThe VE

    - 8 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    VR Technology

    Input devices 3D Trackers 3D Mice (or Joystick) Data gloves

    Output devices Head-mounted displays (HMDs) Headphones Haptic devices

    force feedback

    CAVEs Surround projection technology A room with walls and/or floor formed by rear

    projection screens Turning your head doesnt necessitate redraw Investment cost is very high

  • - 9 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    A Simple VR System

    You can experience a virtual environment using a typical personal computer and a few items of specialized hardware:

    for a non-immersive system: a 3D graphics card, a 3D sound card,

    an immersive system also requires a head-mounted display (HMD) a 6D tracker. Some force feedback input device

    You can get a HMD for less than $____

    - 10 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    Image Generation Problems

    Only 1/60 of a second available per image.

    The geometry of realistic VE is very complex.

    New approaches needed: Image-based rendering Organization of scene data Hidden surface removal

    VR might lead us to a new generation of computer graphics algorithms.

    - 11 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    VR Research

    VR is a convergence of many disciplines

    Important subjects Psychological factors Interactive devices Man-machine interaction Distributed virtual environments Real-time rendering algorithms Simulation Collision detection Database design Artificial life

    - 12 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    The Future of VR

    Virtual Reality is a growing industry

    PC and specialized hardware are gettingbetter, faster and cheaper

    Maybe 3D user interfaces will replace the windows based ones?

    Far reaching ideas The retinal display Tracking based on the nervous system

    So a virtual reality is a synthetic sensory experience which may one day be indistinguishable from the real physicalworld - Kalawsky, R.S. (1993)

  • - 13 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    VR and the Internet?

    Virtual Reality Modeling Language (VRML)

    VRML97 has been accepted as an ISO Standard

    VRML neither requires nor imposes immersion.

    Not VR?

    What is VRML? A 3D interchange format A 3D analog to HTML A technology to integrate 3D, 2D, text and

    multimedia into one coherent model.

    Extensible 3D (X3D) Graphics Extending and upgrading the geometry

    and behavior capabilities of the VRML97 using XML.

    - 14 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality

    References

    Understanding Virtual Reality, Sherman and Craig, Morgan Kaufmann, 2003.

    Virtual Reality Systems, John Vince, Addison-Wesley, 1995

    The Computer Image. Alan Watt, Fabio Policarpo, Addison-Wesley, pp. 541-590, 1998

    Virtual Reality, Zheng, Chan, Gibson, IEEE Potentials, pp. 20-23, April-May 1998.

    Whats Real About Virtual Reality, Brooks, IEEE Computer Graphics and Applications, pp. 16-27, November/December 1999

    The Virtual Reality Modeling Language Explained, Carey, IEEE Multimedia, pp.84-93, July-Sept. 1998

    Web3D Consortium http://www.web3d.org

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