In most body-movement-tracking VR systems, users have to wear sensors on various parts of their body, and/or they must remain within the confines of a base station. The free-roaming Surplex system, however, is claimed to track body movements via a single pair of high-tech shoes.
Currently the subject of a Kickstarter campaign, the Surplex VR Full-Body Tracking Shoes (as they're officially called) are claimed to work with all SteamVR-compatible headsets. And because they communicate with the user's gaming PC via Wi-Fi, they're not limited to use in one precisely defined physical space.
The insole of each shoes contains 240 pressure sensors. These detect the changes in foot pressure that occur not only as the user walks, runs or stands in place, but also as they move their upper body. The pressure data is combined with output from a 9-axis IMU (inertial measurement unit), reportedly allowing the system to continuously track the position and rotation of the user's feet, knees, waist, chest and elbows.
According to the designers, the system is accurate at gauging body position to within 5 cm (2 in), and has a latency rate of about 30 milliseconds. The fancier Pro version of the shoes has a claimed runtime of nine hours per charge, and an update rate of 60 Hertz – the Basic version goes for six hours at 30 Hertz.
Both models support user weights ranging from 50 to 120 kg (110 to 265 lb).
Assuming the Surplex VR shoes reach production, a pledge of US$169 will get you a pair of the Basics, with $199 required for a pair of the Pros – those figures are 25 percent off the planned retail price.
You can see the shoes in use, in the following video.
Sources: Kickstarter, Surplex