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 1
2. Contents • Virtual Reality (VR) • Locomotion • Interaction techniques • Interaction techniques for locomotion in VR 2
3. 3 Oculus Rift - 2011/2012 HTC Vive - 2015 Google Daydream - 2016 Google CardBoard - 2014 Latest VR Wave
4. 4 Somniacs Birdly - 2014? Vituix Omni - 2013 Latest VR Wave
5. VR - A Growing Industry 5
6. CAVE VR Systems 6
7. Locomotion 7 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)
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. 8
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 9
10. 10 Classification of Interaction Techniques for Locomotion
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). 11
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... 12
13. Positional Tracking Systems 13 • Specific to VR ◦ Valve Lighthouse (HTC Vive) ◦ Oculus Room Scale • Generic ◦ Optical / Magnetic ◦ Inside-out / Outside-in • Important to have 6 DOF ◦ Head tracking
14. Real Locomotion Techniques Unmediated Warning Resetting / Reorienting Scaling Redirecting Dynamic VE 14 Sub-categories distinguish between different system’s response to the user’s locomotion
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
16. Unmediated 16 • 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)
17. Unmediated • Mobile VR (6DOF) systems increase mobility • Expensive, not yet for generalized personal consumption 17
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
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. 19
20. Warning 20 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)
21. Warning - Magic Barrier 21 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
22. Warning - CloudWalker 22 • 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)
23. Real Locomotion Techniques Unmediated Warning Resetting / Reorienting Scaling Redirecting Dynamic VE 23 Sub-categories distinguish between different system’s response to the user’s locomotion
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. 24
25. Resetting / Reorienting: Freeze - Backup 25 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)
26. Resetting / Reorienting: Freeze - Turn 26 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)
27. Resetting / Reorienting: 2:1 - Turn 27 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)
28. Resetting / Reorienting: Variations 28 • 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)
29. Real Locomotion Techniques Unmediated Warning Resetting / Reorienting Scaling Redirecting Dynamic VE 29 Sub-categories distinguish between different system’s response to the user’s locomotion
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. 30
31. Simple scaling 31 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
32. Scaling Seven League Boots - Interrante, Ries & Anderson. (2007) 32 • 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
33. Real Locomotion Techniques Unmediated Warning Resetting / Reorienting Scaling Redirecting Dynamic VE 33 Sub-categories distinguish between different system’s response to the user’s locomotion
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). 34
35. Redirecting 35 Neth, Souman, Engel, Kloos, Bülthoff & Mohler (2012)
36. Redirecting 36 • 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)
37. Redirecting - Strategies 37 Hodgson, E., & Bachmann, E. (2013).
38. Redirecting 38 Matsumoto, Ban, Narumi, Yanase, Tanikawa & Hirose (2016).
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
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
41. Dynamic VE 41 Suma, Clark, Krum, Finkelstein, Bolas & Warte (2011)
42. Dynamic VE 42 • Explores “change blindness” effect • Changes to the VE must be minimal and done carefully • Users may notice the changes! • Works for structured, closed environments
43. Dynamic VE 43 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)
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 44
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
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
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 SIGGRAPH 2016 Emerging Technologies on - SIGGRAPH ’16 (pp. 1–2). New York, New York, USA: ACM Press. https://doi.org/10.1145/2929464.2929482 • 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
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 Symposium on 3D User Interface 2013, 3DUI 2013 - Proceedings, 195–196. 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 orientation in large virtual environments using scaled translational gain. In Proceedings of the 3rd symposium on Applied perception in graphics and visualization - APGV ’06 (p. 21). New York, New York, USA: ACM Press. https://doi.org/10.1145/1140491.1140495 • 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 Symposium on Applied Perception in Graphics and Visualization - APGV ’07, 1(212), 41. https://doi.org/10.1145/1272582.1272590