Augmented Reality Browser Survey - Institute for Computer Graphics
Realtime 3D Computer Graphics Virtual Reality
Transcript of Realtime 3D Computer Graphics Virtual Reality
Realtime 3D Computer GraphicsVirtual Reality
Virtual Reality Input Devices
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
VR input devices! Special input devices are required for interaction,navigation and
motion tracking (e.g., for depth cue calculation):
1. Motion Trackers: Position and orientation of a reference system in 3D requires to measure 6 Degrees of Freedom (DOFs).
2. 3D Mice/Wands etc. : Specialized devices for point and click WIMP1-style metaphors have to account for additional DOFs.
3. Joint sensors: Sensors which measure movement of user’s joints (Also possible with trackers and inverse kinematics).
4. Props: Real placeholders for virtual objects.5. Movement effect sensors: Measure the effect user movement
has to the surrounding (no kinematics involved).6. Skin sensors, neural interfaces, bio-sensors: Measure skin
resistance, brain activity and other body related data.
…and hybrid devices.1WIMP: Windows, Icons, Menu, Pointer
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
VR input devicesInput is measured by a multitude of physical and biological
principles, e.g.,1.electro-magnetism2.optics (marker/marker less, visible spectrum/infrared)3.electrics (voltage, impedance, electrical flow,…)4.acoustics (ultrasound,…)5.inertia
Input devices produce data...•...discrete event based
(buttons, state changers).•...continuously
(discrete but continuously sampled).
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
VR input devices
6DOF Magnetic tracker & DataGlove
• Electromagnetic tracker• used to be most common
see: “put-that-there” (Bolt, 1980)• Transmitter
• Creates three orthogonal low-frequency magnetic fields
• Short range version: < 1m• Long range version: < 3m
• Receiver(s)• Three perpendicular antennas. • Distance is inferred from the
currents induced in the antennas.
- Noisy – requires filtering.- Affected by metal – requires non-linear
calibration.- Wireless versions expensive.
Transmitter
Receiver
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
• Inertial trackers !(Intersense IS-300)
+ Less noise, lag- Only 3 DOFs (orientation)• Use gyroscopes and accelerometers
• Hybrid trackers(e.g.,Intersense IS-600/900)
• inertial (orientation)• acoustic (position)
• Acoustic trackers• Uses ultrasound• Typical setup for 3 DOF:
3 microphones and1 speaker• Distance is inferred from the
travel time of the sound+ No interference with metal+ Relatively inexpensive- Line of sight issues- Sensitive to air temperature
and certain noises Logitech Fly Mouse
VR input devices
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
VR input devices
• Optical marker based tracker• marker reflects IR light• Combined to unique spatial
configuration per tracked position+ No interference with metal+ Low latency+ High resolution- Line of sight issues
(more cameras help)
6DOF optical tracker by ART
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
• 3D mice/wands• Several buttons and sensors
for selection of binary states and/or continuous state changes (e.g., potentiometers).
• Often hybrid devices for additional position/orientation.
VR input devices
tracked wand
space orb
ring mouse
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
VR input devices• CubicMouseTM
• First 12 DOF input device• Tracks position and rotation of rods
using potentiometers• Other shapes and
implementationspossible
• Mini Cubic Mouse• …
pictures courtesy of IMK Fraunhofer Gesellschaft
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
Sensors: 20/suit
100 updates/sec3 meters rangefrom base unitResolution<2 mmand <.2 degrees
Electronic unit(2 hours battery life)
Wireless suit (Ascension Technology)
VR input devices• Data Gloves
• Used to track the user’s finger movements.
• For posture and gesture detection.• Almost always used with a tracker
sensor mounted on the wrist• Common types:
• Body suites • Used to track the overall body
movement• Angles measured by resistance or• by inverse kinematics based on certain
body points
5DT Glove (left)5/16 sensors
• CyberGlove (right)• 18/22 sensors
• here hybrid modification for flexion and pinch
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
Head-propCourtesy of Hinkley et al.
VR input devices
ShapeTape-propcourtesy of Balakrishnan et al.
Cyberglove with haptics
Treadmill types(e.g. bicycles)
! …all the preceding and/or Speech Input
• continuous vs. one-time recognition• choice and placement of microphone• training vs. no training• handling of false positive recognition• surrounding noise interference• Can complement other modes of interaction
! " multi-modal interaction (by, e.g., additionally including gesture processing which benefits from the VR sensory equipment)
Fiktion: Interaktion
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
The Ultimate Display
„The ultimate display would, of course, be a room within which the computer can control the existence of matter. A chair displayed in such a room would be good enough to sit in. Handcuffs displayed in such a room would be confining, and a bullet displayed in
such room would be fatal. With appropriate programming such a display could literally be the
Wonderland into which Alice walked.“
(Sutherland 1965)
Fiktion: Interface für das „Ultimate Display“?
Fiktion: Results of physical contact
Realtime 3D Computer Graphics / Virtual Reality – WS 2005/2006 – Marc Erich Latoschik
References• Bolt, R. A. (1980): Put That There: Voice and Gesture at the Graphics Interface.
In: Computer Graphics 14/3, (pp. 262-270)• Bühl, Achim (1997): Die virtuelle Gesellschaft. Politik, Ökonomie und Kultur im Zeichen des Cyberspace.
In: Gräf, Lorenz/ Krajewski, Markus (Hrsg.): Soziologie des Internet. Handeln im elektronischen Web-Werk, Frankfurt/M. /New York: Campus, 39-59.
• Gibson, William (1984): Neuromancer (first print)• Gibson, William (1999): Neuromancer, 9. Aufl., München: Heyne 1999 • Okoshi, T. (1976): Three-Dimensional Imaging Techniques, Academic Press, New York. • Peters, G. (2000). Theories of Three-Dimensional Object Perception - A Survey. Recent Research
Developments in Pattern Recognition, Transworld Research Network.• Sutherland, I.E. (1968): A Head-Mounted Three-Dimensional Display.
In: AFIPS Conference Proceedings, Vol. 33, Part I, pp. 757-764.