#tech
iPhone has 3D face recon system. And Unreal has a game engine.
And what Unreal did is use the 3D face recon system on iPhone to create a cheap face and head only motion detection system with facial expression.
Cool idea.
Real motion capture devices are pretty expensive and complex and I haven't seen any in real life.
This one sends data as points map file that one can use in application.
https://arstechnica.com/gadgets/2020/07/unreals-new-iphone-app-does-live-motion-capture-with-face-id-sensors/