Jump to content

Predictive tracking: Difference between revisions

No edit summary
No edit summary
Line 2: Line 2:
{{see also|Tracking}}
{{see also|Tracking}}
==Introduction==
==Introduction==
[[Predictive tracking]] is a fundamental technique used in both [[augmented reality]] (AR) and [[virtual reality]] (VR) systems that anticipates where a user's body parts or viewing direction will be in the near future. This computational method works by analyzing current motion patterns, velocity, and acceleration to estimate future positions before they occur<ref name="LaValle2016"></ref>. For example, when a VR game needs to display your virtual hand's position, it doesn't simply render where your hand currently is—it predicts where your hand will be several milliseconds in the future.
[[Predictive tracking]] is a fundamental technique used in both [[augmented reality]] (AR) and [[virtual reality]] (VR) systems that anticipates where a user's body parts or viewing direction will be in the near future. This computational method works by analyzing current motion patterns, velocity, and acceleration to estimate future positions before they occur<ref name="LaValle2016"></ref>. For example, when a VR game needs to display your virtual hand's position, it doesn't simply render where your hand currently is, it predicts where your hand will be several milliseconds in the future.


The primary purpose of predictive tracking is to combat [[latency]] issues inherent in AR and VR systems. Without predictive algorithms, users would experience a noticeable delay between their physical movements and the corresponding visual feedback on their displays. This delay creates a disconnection that not only diminishes the sense of [[immersion]] but can also contribute to [[motion sickness]] and general discomfort<ref name="Abrash2014"></ref>. Through predictive tracking, the system estimates your future orientation and position based on your current input data, significantly reducing perceived latency and creating a more natural and responsive experience.
The primary purpose of predictive tracking is to combat [[latency]] issues inherent in AR and VR systems. Without predictive algorithms, users would experience a noticeable delay between their physical movements and the corresponding visual feedback on their displays. This delay creates a disconnection that not only diminishes the sense of [[immersion]] but can also contribute to [[motion sickness]] and general discomfort<ref name="Abrash2014"></ref>. Through predictive tracking, the system estimates your future orientation and position based on your current input data, significantly reducing perceived latency and creating a more natural and responsive experience.
Line 18: Line 18:


==Latency Sources==
==Latency Sources==
Understanding the sources of latency in AR and VR systems is crucial to implementing effective predictive tracking solutions. A specialized device known as a [[latency tester]] measures "motion-to-photon" latency within a headset—the time delay between physical movement and the corresponding visual update on the display. The longer this delay, the more uncomfortable and less immersive the experience becomes.
Understanding the sources of latency in AR and VR systems is crucial to implementing effective predictive tracking solutions. A specialized device known as a [[latency tester]] measures "motion-to-photon" latency within a headset, the time delay between physical movement and the corresponding visual update on the display. The longer this delay, the more uncomfortable and less immersive the experience becomes.


Several distinct factors contribute to the overall system latency:
Several distinct factors contribute to the overall system latency:
Line 181: Line 181:
<ref name="Welch2002">Welch, G., & Foxlin, E. (2002). "Motion Tracking: No Silver Bullet, but a Respectable Arsenal." IEEE Computer Graphics and Applications, 22(6), pp. 24-38.</ref>
<ref name="Welch2002">Welch, G., & Foxlin, E. (2002). "Motion Tracking: No Silver Bullet, but a Respectable Arsenal." IEEE Computer Graphics and Applications, 22(6), pp. 24-38.</ref>
<ref name="Welch2006">Welch, G., & Bishop, G. (2006). "An Introduction to the Kalman Filter." University of North Carolina at Chapel Hill, Department of Computer Science, Technical Report 95-041.</ref>
<ref name="Welch2006">Welch, G., & Bishop, G. (2006). "An Introduction to the Kalman Filter." University of North Carolina at Chapel Hill, Department of Computer Science, Technical Report 95-041.</ref>
<ref name="Isard1998">Isard, M., & Blake, A. (1998). "CONDENSATION—Conditional Density Propagation for Visual Tracking." International Journal of Computer Vision, 29(1), pp. 5-28.</ref>
<ref name="Isard1998">Isard, M., & Blake, A. (1998). "CONDENSATION-Conditional Density Propagation for Visual Tracking." International Journal of Computer Vision, 29(1), pp. 5-28.</ref>
<ref name="LaViola2003">LaViola, J. J. (2003). "Double Exponential Smoothing: An Alternative to Kalman Filter-Based Predictive Tracking." Proceedings of the Workshop on Virtual Environments, pp. 199-206.</ref>
<ref name="LaViola2003">LaViola, J. J. (2003). "Double Exponential Smoothing: An Alternative to Kalman Filter-Based Predictive Tracking." Proceedings of the Workshop on Virtual Environments, pp. 199-206.</ref>
<ref name="Greer2020">Greer, J., & Johnson, K. (2020). "Multi-modal Prediction for XR Tracking." IEEE Conference on Virtual Reality and 3D User Interfaces (VR), pp. 161-170.</ref>
<ref name="Greer2020">Greer, J., & Johnson, K. (2020). "Multi-modal Prediction for XR Tracking." IEEE Conference on Virtual Reality and 3D User Interfaces (VR), pp. 161-170.</ref>