In case you’ve ever wondered about the math behind placing, say, virtual spiders on my kid works, wonder no more: my teammates have published lots o’ details.

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.

You can play with the feature via Motion Stills for Android and Playground for Pixel phones.