Cheap full-body VR tracking without base station for SteamVR and motion capture launches

Tracking hand movements in VR is now more or less an industry standard, which is helpful for immersion. More specialized systems can also track fingers or feet. As part of an ongoing Crowd Supply campaign, the SlimeVR Butterfly Trackers are now available and promise very accurate and almost full-body tracking.

These devices might be suitable for a wide range of use cases. VTubers could use it to control their avatars just as VR players could use it in games, and motion capture is also an option. Depending on the requirements, the Butterfly Trackers could also be useful in scientific contexts or for the motion analysis of athletes.

The system consists of multiple individual trackers. They can be attached to different parts of the body via a strap. The trackers themselves weigh less than 0.35 oz and are thinner than 0.28 inches, so they should be rather unobtrusive. The system utilizes IMU sensors to detect movement, and that data can be transmitted over distances of more than 33 ft, for example to a computer, smartphone or headset. The SlimeVR server combines data from these separate sensors.

Most notably, no base stations or cameras are required. The company claims 360-degree coverage since the sensors capture their own data and are not dependent on staying in the line of sight of a camera. Latency is listed as under 15 ms, and precision (or accuracy) is given as 0.39 to 1.97 inches. That likely means very subtle motions, such as trembling, can’t be detected.

According to the manufacturer, there is native support for SteamVR and thus for various games, as well as OSC and VMC. Motion capture in Blender and Unity is said to be rather straightforward with the corresponding plugins. Battery life is listed at more than 48 hours. Backers can reserve a bundle with six trackers for $279, but the usual risks of crowdfunding campaigns apply.