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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<ul><li><p>- 1 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>Virtual Reality (VR)</p><p>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.</p><p>Questions:1. What is VR now?2. What might it become?3. What technology problems </p><p>need to be solved?</p><p>June 6, 2003</p><p>- 2 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>What is Virtual Reality?</p><p> A medium composed of interactive computer simulations giving users the feeling of being present in the simulations.</p><p> 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.</p><p> Virtual reality is an artificial world generated by a computer. Participants can observe the world and interact with the simulated environment. </p><p> 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.</p><p> An immersive interactive system VR is about Fooling the mind</p><p>- 3 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>Key Elements</p><p> Real-time graphics framerate: 30 frames/sec polygons: 50K/frame (more would be nice) resolution: as much as you can get </p><p> Low latency time lag between sensing a change and updating the picture 1 ms latency =&gt; 1 mm error (at common head/hand speed)</p><p> Interactive manipulation possible? response times</p><p> Multi-sensory vision sound force feedback</p><p>Real-time graphics:- You do it really fast- You do it slightly slower- You do it ok- You do it badly</p><p>Real-time programming:- You do it = you succeed- You dont do it</p><p>- 4 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>Applications</p><p> 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)</p><p>VR Systems were not developed to meet aspecific need; they were developed becausethey were possible - John Vince</p></li><li><p>- 5 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>History (very incomplete)</p><p> 1957 Morton Heilig invented the Stereoscopic TV </p><p>Apparatus for Individual Use. (Patented 1960) 1960</p><p> The Boeing Corporation coined the term computer graphics.</p><p> 1963 Ivan Sutherland submitted his doctoral thesis </p><p>SKETCHPAD: A man-machine graphical communication system.</p><p> 1965 Ivan Sutherland published The Ultimate Display.</p><p> 1968 Ivan Sutherland published A Head-mounted Three </p><p>Dimensional Display. 1989</p><p> Jaron Lainer coined the term virtual reality. 1993</p><p> SGI announced the Reality Engine.</p><p>- 6 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>VR Systems</p><p> VR Systems can be divided intothree groups</p><p> non-immersive systems (like workstations) immersive systems (like HMD or CAVE) hybrid systems (graphics on top of real world)</p><p> also called: augmented reality systems</p><p> The following conditions are important to experience full immersion: </p><p> Full field of vision display, usually produced by the wearing of a Head Mounted Display. </p><p> Tracking of the position and attitude of the participant's body. </p><p> Computer tracking of the participant's movements and actions. </p><p> Negligible delay in updating the display with feedback from the body's movements and actions. </p><p>- 7 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>A Generic VR System</p><p>Physical simulationand animation</p><p>Illumination model</p><p>Objects (geometry&amp; other properties)</p><p>Collision detection</p><p>visual</p><p>audio</p><p>haptic</p><p>hand position</p><p>head position</p><p>Inputs OutputsThe VE</p><p>- 8 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>VR Technology</p><p> Input devices 3D Trackers 3D Mice (or Joystick) Data gloves</p><p> Output devices Head-mounted displays (HMDs) Headphones Haptic devices</p><p> force feedback</p><p> CAVEs Surround projection technology A room with walls and/or floor formed by rear </p><p>projection screens Turning your head doesnt necessitate redraw Investment cost is very high</p></li><li><p>- 9 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>A Simple VR System</p><p> You can experience a virtual environment using a typical personal computer and a few items of specialized hardware: </p><p> for a non-immersive system: a 3D graphics card, a 3D sound card, </p><p> an immersive system also requires a head-mounted display (HMD) a 6D tracker. Some force feedback input device</p><p> You can get a HMD for less than $____</p><p>- 10 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>Image Generation Problems</p><p> Only 1/60 of a second available per image.</p><p> The geometry of realistic VE is very complex.</p><p> New approaches needed: Image-based rendering Organization of scene data Hidden surface removal</p><p>VR might lead us to a new generation of computer graphics algorithms.</p><p>- 11 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>VR Research</p><p> VR is a convergence of many disciplines</p><p> Important subjects Psychological factors Interactive devices Man-machine interaction Distributed virtual environments Real-time rendering algorithms Simulation Collision detection Database design Artificial life</p><p>- 12 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>The Future of VR</p><p> Virtual Reality is a growing industry</p><p> PC and specialized hardware are gettingbetter, faster and cheaper</p><p> Maybe 3D user interfaces will replace the windows based ones?</p><p> Far reaching ideas The retinal display Tracking based on the nervous system</p><p>So a virtual reality is a synthetic sensory experience which may one day be indistinguishable from the real physicalworld - Kalawsky, R.S. (1993)</p></li><li><p>- 13 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>VR and the Internet?</p><p> Virtual Reality Modeling Language (VRML)</p><p> VRML97 has been accepted as an ISO Standard</p><p> VRML neither requires nor imposes immersion.</p><p> Not VR?</p><p> What is VRML? A 3D interchange format A 3D analog to HTML A technology to integrate 3D, 2D, text and </p><p>multimedia into one coherent model.</p><p> Extensible 3D (X3D) Graphics Extending and upgrading the geometry </p><p>and behavior capabilities of the VRML97 using XML. </p><p>- 14 - Thomas Larsson, IDtMlardalens hgskolaIntroduction toVirtual Reality</p><p>References</p><p> Understanding Virtual Reality, Sherman and Craig, Morgan Kaufmann, 2003.</p><p> Virtual Reality Systems, John Vince, Addison-Wesley, 1995</p><p> The Computer Image. Alan Watt, Fabio Policarpo, Addison-Wesley, pp. 541-590, 1998</p><p> Virtual Reality, Zheng, Chan, Gibson, IEEE Potentials, pp. 20-23, April-May 1998.</p><p> Whats Real About Virtual Reality, Brooks, IEEE Computer Graphics and Applications, pp. 16-27, November/December 1999</p><p> The Virtual Reality Modeling Language Explained, Carey, IEEE Multimedia, pp.84-93, July-Sept. 1998</p><p> Web3D Consortium</p></li></ul>


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