Bonelab plans to implement the inside-out upper body tracking feature of Quest 3 & 3S.
Stress Level Zero's Brandon J Laatsch described inside-out body tracking as "the most game changing feature of VR hardware since tracked controllers in 2016", and said "Other hardware players either need to step up and develop it or concede the space to those who do because it will create an insurmountable divide."
Laatsch says inside-out body tracking will arrive in Bonelab in either Patch 7 or Patch 8. Patch 6 released in August, following Patch 5 in July and Patch 4 in June, which brought Quest 3 enhancements and major physics upgrades. There's no timeline for Patch 7 yet.
Inside-Out Body Tracking (IOBT) is a Meta feature that leverages the side cameras of Quest 3 and Quest 3S, which face downward, to track your wrist, elbows, shoulder, and torso using advanced computer vision algorithms. It prevents the issues with inverse kinematics (IK) estimated arms, which are often incorrect and feel uncomfortable because the system is just making guesses from the location of your head and hands. When developers integrate IOBT, you see your arms and torso in their actual positions - not an estimate.
IOBT shipped in December. However, almost a year later it's still only used by a tiny handful of standalone apps, including Swordsman VR, Drunkn Bar Fight, XRWorkout, and FastHands. In fact Meta's own new avatar system doesn't even use IOBT.
Given Bonelab's focus on physics-based full body interactivity with the virtual world, using IOBT could make it a significantly less janky experience, bringing a quality of embodiment that the game was clearly designed for but mainstream VR hardware couldn't deliver until recently. As such, it's easy to understand why Laatsch is so excited to bring IOBT to Bonelab.