Full Body Tracking

Overview

Full body tracking (FBT) lets Basis drive your avatar's hips, feet and limbs from physical trackers rather than estimating them from your head and hands alone. Basis reads trackers through OpenXR (including the HTC Vive tracker profile), and works out which tracker belongs on which part of your body automatically from a single calibration pose.

The roles Basis can assign a tracker to are:

• Hips and Chest
• Left / Right Foot and Left / Right Toes
• Left / Right Lower Leg (shins)
• Left / Right Shoulder
• Left / Right Lower Arm (forearms)

Calibrating

Basis uses constellation calibration: you stand in a T-pose and it classifies each free tracker by where it sits in space relative to your headset, then assigns it to the closest matching body role.

1. Put on your headset and trackers and make sure each tracker is tracking.
2. Open the tracker calibration option in Settings.
3. Stand in a T-pose — feet roughly shoulder-width apart, arms straight out to the sides.
4. Trigger calibration and hold the pose until it completes.

Your avatar is put into a reference T-pose during calibration, the trackers are classified, and the FBT roles bind to your avatar's bones.

Tracker pairing

Symmetrical tracker setups (for example a pair of ankle trackers) can be paired so Basis treats them as a linked set during classification. Pairings are saved to disk and reused, so you don't have to re-pair them every session.

Manual role overrides

If the automatic classifier keeps misassigning a particular tracker — common with unusual mounting positions — you can force a tracker to a specific role. An override skips the scoring step for that tracker and assigns it directly, so the rest of the constellation still calibrates around it.

Like pairings, overrides persist between sessions, so a setup you've tuned once keeps working on the next launch with the same trackers.