contents 1. introduction introduction 2. virtual reality (vr) virtual reality (vr) 3. vr v/s ar vr...
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Contents1. Introduction2. Virtual Reality (VR)3. VR v/s AR4. Need for Augmented Reality (AR)5. Design6. Challenges7. Applications8. Future Prospects9. Conclusion10.References
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1. IntroductionAugmented Reality :
An Augmented Reality system generates a composite view for the user. It’s a combination of the real scene viewed by the user and a virtual scene generated by the computer that augments the scene with additional information.
AR systems have the following three properties:1. Blends real and virtual, in real environment2. Interactive in real time 3. Registered in 3D
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1.1 AR View
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2. Virtual Reality (VR)“A computer generated, interactive, three-
dimensional environment in which a person is immersed.”
Requires high performance computer graphics to provide an adequate level of realism
Blocks out all the external world and present to the wearer a view that is under the complete control of the computer
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3. VR v/s AR
Virtual RealityTotally immersive
environment.Completely immersed
in an artificial world and becomes divorced from the real environment
Visual senses are under control of system
Augmented RealitySystem augments
the real world sceneUser maintains a
sense of presence in real world
Needs a mechanism to combine virtual and real worlds
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3.1 Reality-Virtuality Continuum
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Milgram’s Reality-Virtuality Continuum
The real world and a totally virtual environment are at the two ends of this continuum with the middle region called Mixed Reality. Augmented Virtuality -> systems which are mostly synthetic with some real world imagery
4. Need for ARFor some applications, it may be desirable to
use as much as possible real world in the scene rather creating a new scene using computer imagery. Eg. Medicine and telerobotics
Can maintain the high-level of detail and realism that one finds in the real world.
AR enhances real world, while VR replaces or simulates the real world
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5. DesignThe four components of any AR system are
5.1 The Display System (usually an HMD)5.2 The Tracking System5.3 Mobile Computing Power5.4 Input device (usually a wrist mounted keyboard)
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5.1 The Display SystemAllows the user to see the image and text
created by the Augmented Reality SystemsThere are basically two types of display systems:
5.1.1 Optical see-through5.1.2 Video see-through
5.1.1 Optical see-through displays• Direct viewing of real world through naked eye• Uses optical combiners- partially reflective,
partially transmissive• Similar to HUDs used in military aircrafts
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5.1.1 Optical see-through display
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5.1.2 Video see-through displayCombination of closed-view HMD and one or
more head-mounted video camerasVideo from camera combined with graphic
images created by the scene generator
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Advantages of Optical see-through displaySimplicity- cheap and simple (one video stream).Resolution- user’s real world view is not retardedSafetyNo eye offset
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Advantages of Video see-through display Flexibility in composition strategies Wide field of view Real and virtual view delays can be matched Additional registration strategies Easier to match brightness of real and virtual objects
5.2 The Tracking SystemUsed to find the position and orientation of the viewerWhere the user is located with respect to his
surroundingsMovement of user’s head
The two main functions of tracking system:Find the person’s position in space
Using the three Cartesian coordinates- x, y and zFind the direction in which the person is looking
Using three angles- pitch(or elevation), roll and yaw(azimuth)
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These are called six degrees of freedom (DOF)
Tracking System (contd)The six degrees of freedom
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•Positive pitch- upward head tilt•Positive roll- left head tilt•Positive yaw- left head rotation
2 conventional tracking devices used: Hi-ball Tracking System(for indoor applications) GPS (for outdoor applications)
5.3 Mobile Computing PowerIdeal computing device – wearable computers
Freedom in movementErgonomicsRuggedness (depends on the application)
Features: Portable while operational Hands-free use Attention getting Always ON
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Mobile Computing Power (contd)
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Eg. Xybernaut Wearable Computer
HMD CPU module Wrist-mounted Keyboard
6. Challenges/Design Issues6.1 Display Issues
Focus and contrast Eye offset Field of view
6.2 Registration Issues6.3 Tracking Issues
Sample rate Update rate Latency
6.4 Portability Issue
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6.2 Registration Issues
6.2.1 Static ErrorsOptical DistortionsMechanical misalignments Incorrect viewing parameters(FOV,
interpupillary dist.)
6.2.2 Dynamic Errors System lag (latency)
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6.3 Tracking IssuesSample rate- rate at which sensors are checked for dataUpdate rate- The rate at which the system reports new
position coordinates to the host computerLatency(or lag)- delay between the movement of the
remotely sensed object and the report of the new position
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6.4 Portability Issue The user moves around Ergonomics (when mounted and used for a long duration) The power consumption should also be at minimum since the system is to run on batteries to facilitate portability
7. Applications7.1 Medical
Training aid – Virtual instructions for a novice surgeon
Surgery – ultrasound imaging 7.2 Manufacturing and repair
Machine assembly – Instructions as 3-D drawings superimposed upon the actual equipment
7.3 MilitaryBARS- Battle Field Augmented Reality SystemMilitary Aircrafts-HUDs and HMSs
7.4 Annotation and VisualizationUsed in sports – to name or point out cars in a race
7.5 EntertainmentGames – the most recent one being an AR version
of the popular game Quake- ARQuake21
7.1 Applications: Medicine
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A tumor surgery
Laparoscopy
7.2 Applications: Manufacture/Repair
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Laser Printer Assembly
7.3 Applications: Military
BARS
7.4 Applications: Annotation
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8. Future Prospects
AR has a wide vista of applications in store for future:Medical: In minimal invasive surgeries,
endoscopy, laparoscopyCollaborative Applications: Military- BARSCommercial Applications: Ads, games and sports-
Race F/XTourism: ARCHEOGUIDE- helps tourists with info.
Implemented in Greece on a test basis.Multimodal displays (haptics and auditory
interactions)
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9. ConclusionAR systems are far behind VR systems in terms of maturity. Augmented Reality is a relatively new field, where most of the research efforts have occurred in the past few years. Because of the numerous challenges and unexplored avenues in this area, AR will remain a vibrant area of research for at least the next several years.
After the basic problems with AR are solved, the ultimate goal will be to generate virtual objects that are so realistic that they are virtually indistinguishable from the real environment.
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10. References[1] Ronald T. Azuma, “A Survey of Augmented Reality”,
Presence- Teleoperators and Virtual Environments, Volume 6, pp. 355-385, 1997
[2] Ronald T. Azuma, Yohan Baillot, Steven Feiner, Simon Julier, “Recent Advances in Augmented Reality”, IEEE Computers Graphics & Applications, Volume 21, November 2001
[3] Claudio Kimer,Ezequiel R. Zorzal, Tereza G. Kirner, “Case Studies on the Development of Games Using Augmented Reality”, IEEE International Conference on Systems, Man and Cybernetics, October 2006
[4] Lyu M. R, King I, Wong T. T, “ARCADE: Augmented Reality Computing Arena For Digital Entertainment”, Aerospace Conference 2005
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THANK YOU…..
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