  Augmented Reality (AR) brings immersive experiences to users. With recent
advances in computer vision and mobile computing, AR has scaled across
platforms, and has increased adoption in major products. One of the key
challenges in enabling AR features is proper anchoring of the virtual content
to the real world, a process referred to as tracking. In this paper, we present
a system for motion tracking, which is capable of robustly tracking planar
targets and performing relative-scale 6DoF tracking without calibration. Our
system runs in real-time on mobile phones and has been deployed in multiple
major products on hundreds of millions of devices.
