Scheduled for December, Quest 3 will gain features such as upper body tracking and artificial intelligence estimation of leg position through a software update.
Other major VR systems can only track your head and hands, some can also track your eyes, and a few can also track facial expressions. The Quest 3 doesn't have eye or face tracking, but it will get a tracking feature not found on other headsets to date.
Quest 3将能够利用其朝下的侧面摄像头，利用先进的计算机视觉算法追踪你的手腕、肘部、肩膀和躯干。Meta称之为内外部全身追踪（IOBT）。
This would solve problems caused by inverse kinematics (IK) estimated arms, as the system can only make guesses based on your head and hand position, which is often inaccurate and uncomfortable. After this update on Quest 3, when the app integrates the new SDK update, you should be able to see actual representations of your arms and torso, rather than estimates.
Upper body tracking also allows developers to position the sticks in the direction of your body, rather than just your head or hands, so you can lean over the edge of a cliff as if it were real.
Meta will also launch generative leg technology in December, which will use "cutting-edge" artificial intelligence models to estimate your leg position, the result of years of research by the company. On Quest 3, the generative leg technology will use upper body tracking as input to provide more realistic estimates, but on Quest Pro and Quest 2, it relies solely on the head and hands for estimation.
The generative leg system is only an estimator, not a tracker, so it can detect movements like jumping and squatting, but it cannot capture many actual movements like knee lifts.
Internal and external full-body tracking and generative leg technology enable full-body movement in virtual reality, called "full-body synthesis," without the need for external hardware.
Meta announced that full-body integration will be available on applications such as Supernatural, Swordsman VR, and Drunk Bar Brawl, and will make the SDK available to other developers in December.
EN_US 
ZH