Object tracking is essential for a fully immersive virtual reality experience. In order to support interaction in the virtual space, the system needs to determine the location of the headset and peripherals, so as to realistically depict the virtual world. It can be said that tracking accuracy is an important puzzle for the persuasiveness and immersion of virtual reality.
A few days ago, the German organization Virtual Dimension Center (VDC) released a head-mounted display tracking system measurement report called "Head-Mounted Displays: Messung räumlicher Präzision bei VR-Trackingsystemen".
Virtual Dimension Center (VDC) is Germany's leading virtual engineering and virtual reality network organization. Since 2002, VDC, which includes members such as research institutions, technology suppliers, and service providers, has been cooperating on topics such as simulation, visualization, computer-aided engineering, and virtual reality.
For this experiment, the researchers attached the device to the robot arm and moved the virtual reality controller between two points 500 mm apart. The tracking performance of position 1 and position 2 will be measured by dedicated software and tools, and the results will be presented in the form of tables and graphs, including maximum deviation, average value and standard deviation.
As shown in the figure, at position 1 where the controller is closer to the VR headset, SteamVR Tracking (outward-inward tracking) is the most accurate tracking system, with a deviation between 084 and 0205 mm. Oculus Rift S (inside-out tracking), Oculus Quest (inside-out tracking) and WMR (inside-out tracking) are close to standard deviations. The error of Vive Cosmos is obviously higher: the deviation of more than 2 to 3 mm per axis is significantly higher than the average.
It should be noted that ART's ultra-precision tracking system is designed for professional application scenarios and is not sold to ordinary users. We can see that the deviation of this outward-inward tracking system is less than 0.1 mm.
For position 2 where the controller is farther away from the VR headset, the accuracy of the inside-out tracking system is significantly lower than that of the outside-in tracking.
According to the measurement results, the tracking system accuracy of Oculus Rift S is lower than that of Oculus Quest. This is a bit surprising, because the PC provides more computing performance, and Rift S is equipped with an additional tracking camera.
The researchers pointed out that there are significant differences in the accuracy of each tracking system: ART and SteamVR Tracking have sub-millimeter accuracy and are suitable for areas that require high-precision tracking, such as design, 3D modeling, medical technology and simulation.
However, since there is no need to install external sensors indoors, the use of inside-out tracking is more flexible. The research report stated that systems such as Quest have sufficient accuracy in collaborative applications and are suitable for use cases such as communication, meetings, training, and product demonstrations.