Scalable optical tracking for navigating large virtual environments using spatially encoded markers

Abstract

In this paper we present a novel approach for tracking the movement of a user in a large indoor environment. Many studies show that natural walking in virtual environments increases the feeling of immersion by the users. However, most tracking systems suffer from a limited working area or are expensive to scale up to a reasonable size for navigation.Our system is designed to be easily scalable both in working area and number of simultaneous users using inexpensive off-the-shelf components. To accomplish this, the system determines the 6 DOF pose using passive LED strips, mounted to the ceiling, which are spatially encoded using De Bruijn codes. A camera mounted to the head of the user records these patterns. The camera can determine its own pose independently, so no restriction on the number of tracked objects is required. The system is accurate to a few millimeters in location and less than a degree in orientation. The accuracy of the tracker is furthermore independent of the size of the working area which makes it scalable to enormous installations. To provide a realistic feeling of immersion, the system is developed to be realtime and is only limited by the framerate of the camera, currently at 60Hz.

Tracking and Co-Location of Global Point Clouds for Large-Area Indoor Environments

“…When natural images features are not a strict requirement for the application at hand, a set of artificial features can be introduced consisting of bar codes, QR codes, ArUco (Garrido-Jurado et al, 2014) or alternatively designed custom markers (Jorissen et al, 2014). Maesen et al (2013) and Podkosova et al (2016) have laid the groundwork for this approach with their fundamental research on large-area tracking, but evaluation has only been performed in very constrained environments.…”

Mapping virtual and physical reality

“…However, real walking requires sufficiently large physical spaces, which are almost always in different (usually smaller) sizes and shapes from the corresponding virtual spaces (unless the latter are designed from the former, as in [Simeone et al 2015]). Techniques such as physical props [Cheng et al 2015], warped spaces [Suma et al 2012;Vasylevska et al 2013], and redirected walking [Razzaque et al 2001;Maesen et al 2013;Zmuda et al 2013;Nescher et al 2014] have been proposed to reconcile the virtual and physical worlds, and behavior studies have indicated that limited amounts of space distortion can be acceptable for VR navigation [Steinicke et al 2008;Zhang and Kuhl 2013;Nilsson et al 2014;Bruder et al 2015]. However, existing methods are not general enough to map between a given pair of virtual and physical environments.…”

Robust Global Tracking Using a Seamless Structured Pattern of Dots

“…This results in a system that can be easily extended to larger areas, but as a trade-off only returns a pose relative to the starting position and not to a fixed predefined coordinate system. Maesen et al [18] recently proposed a new system that encodes the position of the dots using De Bruijn codes and decodes the positions with the help of cross-ratios. This allows the tracker, contrary to their earlier system, to estimate the pose in relation to a predefined coordinate system.…”