Interaction Techniques for Locomotion in Virtual Reality

Transcript

1. Interaction Techniques for
   Locomotion in Virtual Reality
   DEI/CISUC Seminars, April 11, 2018
   Jorge C. S. Cardoso
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2. Contents
   ● Virtual Reality (VR)
   ● Locomotion
   ● Interaction techniques
   ● Interaction techniques for locomotion in VR
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3. 3
   Oculus Rift - 2011/2012
   HTC Vive - 2015 Google Daydream - 2016
   Google CardBoard - 2014
   Latest VR Wave
   

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4. 4
   Somniacs Birdly - 2014?
   Vituix Omni - 2013
   Latest VR Wave
   

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5. VR - A Growing Industry
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6. CAVE VR Systems
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7. Locomotion
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   Travel, or Viewpoint Motion Control, is one of
   the most basic and universal interactions found
   in virtual environment applications. We define
   travel as the control of the user’s viewpoint
   motion in the three-dimensional environment." --
   (Bowman, 1999, p. 26)
   

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8. Interaction Technique
   By interaction technique we mean the
   combination of physical devices, the physical
   or mental actions one must perform while
   using those devices, and the system's
   response -- be it physical or purely digital --
   including the feedback necessary for the user
   to understand the result of his actions.
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9. Interaction Technique
   The analysis is not focused on any particular
   type of VR application
   Techniques are not appropriate for all
   applications
   Techniques are not mutually exclusive
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10. 10
    Classification of Interaction Techniques for Locomotion
    

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11. Real Locomotion
    In real locomotion users have to physically
    move from one point to another (translational
    movement) in the real world to affect
    movement in the virtual environment. Real
    locomotion is generally accomplished through
    walking, but other means of physical
    locomotion can also be used (vehicles).
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12. Real Locomotion
    Real locomotion in VR systems produces the
    same proprioceptive, vestibular, cues as
    walking in the real world.
    Visual, auditory, tactile cues may differ...
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13. Positional Tracking Systems
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    ● Specific to VR
    ○ Valve Lighthouse (HTC Vive)
    ○ Oculus Room Scale
    ● Generic
    ○ Optical / Magnetic
    ○ Inside-out / Outside-in
    ● Important to have 6 DOF
    ○ Head tracking
    

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14. Real
    Locomotion
    Techniques
    Unmediated
    Warning
    Resetting / Reorienting
    Scaling
    Redirecting
    Dynamic VE
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    Sub-categories distinguish
    between different system’s
    response to the user’s
    locomotion
    

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15. Unmediated
    In unmediated locomotion, the physical
    position/orientation is directly mapped to a
    virtual position/orientation. The behavior of the
    system does not change in response to
    physical movement. This means that the
    system has no knowledge of the physical
    space and cannot enforce any restrictions on
    where users (try to) go. 15
    

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16. Unmediated
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    ● VE most be built according to the
    available physical space
    ● Issues
    ○ Typically small tracking areas
    (and hence VEs)
    ● Used only in very specific
    (controlled) situations
    Bruder, Interrante, Phillips, & Steinicke (2012)
    

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17. Unmediated
    ● Mobile VR (6DOF) systems increase
    mobility
    ● Expensive, not yet for generalized
    personal consumption
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18. Real
    Locomotion
    Techniques
    Unmediated
    Warning
    Resetting / Reorienting
    Scaling
    Redirecting
    Dynamic VE
    18
    Sub-categories distinguish
    between different system’s
    response to the user’s
    locomotion
    

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19. Warning
    To increase the safety of the VR experience,
    many real locomotion techniques implement
    various kinds of warnings to alert the user
    when he approaches the edges of the physical
    room or tracking area.
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20. Warning
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    https://www.digitaltrends.com/virtual-reality/osvr-protector-roomscale/
    ● Top: Boundary grid in OSVR,
    similar grid used by SteamVR
    ● Bottom: Warning system used by
    Greuter & Roberts (2014)
    ○ Users in red bounding area are
    alerted with a text message over a
    blurred display
    Greuter & Roberts (2014)
    

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21. Warning - Magic Barrier
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    Cirio, Marchal, Regia-Corte, & Lécuyer. (2009)
    ● Yellow tape shows boundary
    at all times
    ● Red tape appears when
    close to the boundary
    ● Hybrid locomotion - the tape
    can be pushed in the
    direction of intended
    locomotion
    ○ Rate-controlling manner
    

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22. Warning - CloudWalker
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    ● Warnings can be multi-modal
    ● Vibrotactile belt with 8 tactors
    around the waist
    ● Auditory feedback for the
    footsteps with different sounds
    for the center and for the edges
    of the cloud
    ● Different physical textures for
    the floor - the center of the cloud
    feels different than the edges.
    Wang, Leach, & Lindeman (2013)
    

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23. Real
    Locomotion
    Techniques
    Unmediated
    Warning
    Resetting / Reorienting
    Scaling
    Redirecting
    Dynamic VE
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    Sub-categories distinguish
    between different system’s
    response to the user’s
    locomotion
    

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24. Resetting / Reorienting
    Reorientation or resetting techniques try to
    semi-automatically reorient the user when he reaches the
    boundary of the tracked area. Reorientation can work either
    by making the user physically rotate so that he faces away
    from the boundaries of the tracked area, or by making the
    user physically translate to the center of the tracking area.
    The user is aware of the reorientation or resetting process.
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25. Resetting / Reorienting: Freeze - Backup
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    1. User reaches the boundaries
    2. Computer informs (text in HMD)
    of need to reset
    3. Tracking system is disabled
    (user’s position in the VE is no
    longer updated).
    4. User is instructed to take steps
    backwards (orientation is active
    so user can look around in the
    VE).
    5. When enough steps are taken, the
    computer indicates for the user to
    stop, displays are unfrozen, user
    is allowed to continue along the
    path
    Williams, Narasimham, Rump, McNamara, Carr,
    Rieser, & Bodenheimer. (2007)
    

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26. Resetting / Reorienting: Freeze - Turn
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    1. User reaches the boundaries
    2. Computer informs of need to
    reset by turning around.
    3. The display of the HMD is frozen,
    freezing the participant’s position
    and yaw angle in virtual space
    4. User turns 180 degrees.
    5. The display is unfrozen, tracking
    is updated, and the subject is
    able to continue traveling along
    his route. Williams, Narasimham, Rump, McNamara, Carr,
    Rieser, & Bodenheimer. (2007)
    

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27. Resetting / Reorienting: 2:1 - Turn
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    1. User reaches the boundaries
    2. Computer informs user should
    turn and keep turning until
    completing a visually full turn in
    the virtual environment.
    3. The rotational gain of the yaw
    angle during this turn is scaled by
    two, such that the user rotates
    180◦ in the physical environment,
    but rotates 360◦ in the virtual
    environment.
    Williams, Narasimham, Rump, McNamara, Carr,
    Rieser, & Bodenheimer. (2007)
    

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28. Resetting / Reorienting: Variations
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    ● Head turns with audio
    instructions
    ● Head turns with visual
    distractors
    ● Rotational gains are applied
    ○ The user turns 180º
    physically , but 360º
    virtually
    ● The purpose is to reduce the
    break in the feeling of
    presence typically
    introduced by the resetting
    process
    Peck, Fuchs, & Whitton (2009)
    

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29. Real
    Locomotion
    Techniques
    Unmediated
    Warning
    Resetting / Reorienting
    Scaling
    Redirecting
    Dynamic VE
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    Sub-categories distinguish
    between different system’s
    response to the user’s
    locomotion
    

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30. Scaling
    Scaling changes the mapping between physical
    and virtual translations so that a small physical
    translation corresponds to a large virtual
    translation. This allows users to travel large
    distances in the virtual environment while
    confined to a relatively small physical area.
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31. Simple scaling
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    Williams, Narasimham, McNamara, Carr, Rieser &
    Bodenheimer. (2006)
    ● Scale translation uniformly on all 3 axis
    ● Always on
    ● Scaling up to 10:1 have been tried
    ● Not adequate for small spaces
    ● Amplifies lateral and vertical head movements
    

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32. Scaling
    Seven League Boots - Interrante, Ries & Anderson. (2007)
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    ● Scaling only on the locomotion axis
    ○ Avoids discomfort caused by amplification of
    small lateral and vertical head movements
    ● Direction of movement
    ○ Previous movement direction + gaze direction.
    ○ If previous displacement is very small: gaze
    direction weight is 1; gaze weight quickly falls to
    0 when moving.
    ■ Movement direction is the gaze direction when users are
    standing still
    ■ Movement direction is previous movement direction
    when users are walking
    ● Manual activation of boots: press a button on a
    controller
    

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33. Real
    Locomotion
    Techniques
    Unmediated
    Warning
    Resetting / Reorienting
    Scaling
    Redirecting
    Dynamic VE
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    Sub-categories distinguish
    between different system’s
    response to the user’s
    locomotion
    

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34. Redirecting
    Redirected Walking works by interactively rotating the virtual scene
    about the user, such that the user is made to continually walk towards
    the farthest “wall” of the tracker area. The user does not notice this
    rotation because the algorithm exploits the limitations of human
    perceptual mechanisms for sensing position, orientation and movement.
    The amount of rotational distortion injected is a function of the user’s
    real orientation and position in the lab, linear velocity, and angular
    velocity. -- Razzaque, Kohn, & Whitton (2001).
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35. Redirecting
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    Neth, Souman, Engel, Kloos, Bülthoff & Mohler (2012)
    

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36. Redirecting
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    ● Amount of rotational gain should be imperceptible
    ○ Physical area of 40m x 40x for generalized redirection
    ● Depends on moving speed
    ● Can be larger if user is rotating their head
    Razzaque (2005)
    

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37. Redirecting - Strategies
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    Hodgson, E., & Bachmann, E. (2013).
    

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38. Redirecting
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    Matsumoto, Ban, Narumi, Yanase, Tanikawa & Hirose (2016).
    

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39. Real
    Locomotion
    Techniques
    Unmediated
    Warning
    Resetting / Reorienting
    Scaling
    Redirecting
    Dynamic VE
    39
    Sub-categories distinguish
    between different system’s
    response to the user’s
    locomotion
    

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40. Dynamic VE
    Manipulate the environment itself to fit a
    predefined physical path. Unlike redirection,
    dynamic manipulation of the VE does not
    introduce any visual-vestibular conflict. It does,
    however, introduce physical incongruences in
    the structure of the VE making it physically
    impossible to create. The challenge is to make
    the changes as subtle as possible. 40
    

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41. Dynamic VE
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    Suma, Clark, Krum, Finkelstein, Bolas & Warte (2011)
    

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42. Dynamic VE
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    ● Explores “change
    blindness” effect
    ● Changes to the VE must
    be minimal and done
    carefully
    ● Users may notice the
    changes!
    ● Works for structured,
    closed environments
    

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43. Dynamic VE
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    If the purpose of the VE does not depend specifically on the spatial
    layout of the environment, we can relax the requirement for architectural
    conformity and allow more daring manipulations...
    Vasylevska, Kaufmann, Bolas & Suma (2013)
    

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44. Conclusion
    Various approaches for
    locomotion in VR
    We have seen just a few for
    “real locomotion”
    Knowing about these can help
    designers of VR systems /
    experiences choose or combine
    the best approaches
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45. Image credits (1/2)
    ● Oculus VR image (slide 3)
    ○ https://pixabay.com/en/man-black-virtual-reality-oculus-1416141/
    ● HTC Vive image (slide 3)
    ○ By Maurizio Pesce [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via
    Wikimedia Commons
    ● Google Cardboard (slide 3)
    ○ By Evan-Amos - Own work, Public Domain,
    https://commons.wikimedia.org/w/index.php?curid=45580283
    ● Daydream image (slide 3)
    ○ Maurizio Pesce, “Me wearing the Daydream View VR Headseet Made By Google”,
    https://www.flickr.com/photos/pestoverde/30120260726
    ● Virtuix Omni image (slide 4)
    ○ By Czar (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via
    Wikimedia Commons
    ● Cave system (slide 6 - left)
    ○ By User:Davepape (own work (self-photograph using timer)) [Public domain], via
    Wikimedia Commons
    ● Cave system (slide 6 - right)
    ○ sean dreilinger durak.org
    https://www.flickr.com/photos/tedxsandiego/11488707685/in/photostream/
    45
    

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46. Image credits (2/2)
    ● Slide 14 - top
    ○ T-tus at the English language Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or
    CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], from Wikimedia
    Commons
    ● Lighthouse (Slide 14 - bottom)
    ○ https://www.vrheads.com/least-painful-way-set-htc-vive-lighthouses
    ● Slide 21 - top
    ○ https://www.digitaltrends.com/virtual-reality/osvr-protector-roomscale/
    ● Slide 33
    ○ By Thijs Kinkhorst (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html),
    CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY 2.5
    (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons
    ● Slide 43
    ○ Change Blindness Redirection in Virtual Reality,
    https://www.youtube.com/watch?v=E_uZ6-0FsXo
    46
    

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47. References (1/2)
    47
    ● Bowman, D. A. (1999). Interaction Techniques for Common Tasks in Immersive Virtual Environments. Georgia
    Institute of Technology.
    ● Bruder, G., Interrante, V., Phillips, L., & Steinicke, F. (2012). Redirecting walking and driving for natural navigation
    in immersive virtual environments. IEEE Transactions on Visualization and Computer Graphics, 18(4), 538–545.
    https://doi.org/10.1109/TVCG.2012.55
    ● Cirio, G., Marchal, M., Regia-Corte, T., & Lécuyer, A. (2009). The Magic Barrier Tape: a Novel Metaphor for Infinite
    Navigation in VirtualWorlds with a RestrictedWalkingWorkspace. In Proceedings of the 16th ACM Symposium on
    Virtual Reality Software and Technology - VRST ’09 (Vol. 1, p. 155). New York, New York, USA: ACM Press.
    https://doi.org/10.1145/1643928.1643965
    ● Greuter, S., & Roberts, D. J. (2014). SpaceWalk : Movement and Interaction in Virtual Space with Commodity
    Hardware. Proceedings of the 2014 Conference on Interactive Entertainment, 1–7.
    ● Hodgson, E., & Bachmann, E. (2013). Comparing four approaches to generalized redirected walking: simulation
    and live user data. IEEE Transactions on Visualization and Computer Graphics, 19(4), 634–43.
    https://doi.org/10.1109/TVCG.2013.28
    ● Interrante, V., Ries, B., & Anderson, L. (2007). Seven league boots: A new metaphor for augmented locomotion
    through moderately large scale immersive virtual environments. IEEE Symposium on 3D User Interfaces 2007 -
    Proceedings, 3DUI 2007, 167–170. https://doi.org/10.1109/3DUI.2007.340791
    ● Matsumoto, K., Ban, Y., Narumi, T., Yanase, Y., Tanikawa, T., & Hirose, M. (2016). Unlimited corridor. In ACM
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    ● Neth, C. T., Souman, J. L., Engel, D., Kloos, U., Bülthoff, H. H., & Mohler, B. J. (2012). Velocity-dependent dynamic
    curvature gain for redirected walking. IEEE Transactions on Visualization and Computer Graphics, 18(7),
    1041–1052. https://doi.org/10.1109/TVCG.2011.275
    

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48. References (2/2)
    48
    ● Peck, T. C., Fuchs, H., & Whitton, M. C. (2009). Evaluation of Reorientation Techniques and Distractors for
    Walking in Large Virtual Environments. IEEE Transactions on Visualization and Computer Graphics, 15(3),
    383–394. https://doi.org/10.1109/TVCG.2008.191
    ● Razzaque, S., Kohn, Z., & Whitton, M. C. (2001). Redirected Walking. In Proceedings of EUROGRAPHICS (pp.
    289–294).
    ● Razzaque, S. (2005). Redirected walking. University of North Carolina at Chapel Hill. Retrieved from
    http://wwwx.cs.unc.edu/~eve/dissertations/2005-Razzaque
    ● Suma, E. A., Clark, S., Krum, D., Finkelstein, S., Bolas, M., & Warte, Z. (2011). Leveraging change blindness for
    redirection in virtual environments. In 2011 IEEE Virtual Reality Conference (Vol. 19, pp. 159–166). IEEE.
    https://doi.org/10.1109/VR.2011.5759455
    ● Vasylevska, K., Kaufmann, H., Bolas, M., & Suma, E. a. (2013). Flexible spaces: Dynamic layout generation for
    infinite walking in virtual environments. IEEE Symposium on 3D User Interface 2013, 3DUI 2013 - Proceedings,
    39–42. https://doi.org/10.1109/3DUI.2013.6550194
    ● Wang, J., Leach, O., & Lindeman, R. W. (2013). DIY World Builder: An immersive level-editing system. IEEE
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    https://doi.org/10.1109/3DUI.2013.6550245
    ● Williams, B., Narasimham, G., McNamara, T. P., Carr, T. H., Rieser, J. J., & Bodenheimer, B. (2006). Updating
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    ● Williams, B., Narasimham, G., Rump, B., McNamara, T. P., Carr, T. H., Rieser, J., & Bodenheimer, B. (2007).
    Exploring large virtual environments with an HMD when physical space is limited. Proceedings of the 4th
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