Understanding Free Roam VR Tracking and Calibration
Introduction This article is a work in progress and will be receiving updates Standalone VR headsets use a tracking technique called visual simultaneous localization and mapping (vSLAM)*. The exterior cameras on your headset create a map of your surroundings, and the headset estimates it’s position based on its approximate distance to various landmarks in your map. *To learn more about SLAM, visit: https://www.mathworks.com/discovery/slam.html How Does Free Roam VR Tracking Work? When you are drawing the “boundaries” on your standalone VR headset, you are drawing the SLAM boundaries. When an headset is reporting its position, it reports its position relative to the SLAM boundaries. SLAM creates a “map” file. When all the HMDs have the same SLAM map: This is how it is kept accurate for everyone. Advantages and Drawbacks of Different Headset Choices HTC VIVE Focus 3, Pico Neo 3 Pro, Pico 4 Enterprise have superior tracking accuracy for Free Roam VR These headsets have superior tracking accuracy, because of a feature called boundary sharing. This means, you can draw the boundary on just 1 of the headsets -> then export that boundary file -> and import it into the other headsets. Then they have exactly the same SLAM map. As long as they are physically in the same space, it is very accurate. Meta Quest Disadvantages Meta does not allow boundary sharing and there is no way to export/import a SLAM map onto multiple headsets. Therefore, your tracking accuracy is determined by how well you are able to replicate and redraw your boundary on each headset, one at a time. Headset Calibration HTC VIVE Focus 3, Pico Neo 3 Pro, Pico 4 Enterprise When you are using HTC VIVE Focus 3, Pico Neo 3 Pro, or Pico 4 Enterprise, there is no need to calibrate your setup. Meta Quest When using Quests, calibration is needed. The calibration is like this: If, during gameplay, a player performs the quick recalibration (by holding the Oculus button for 3 seconds), then the HMD has to be recalibrated at the X spot.