SDK for stop-motion mannequin tracking?

Hi all,

I am looking for a Unity SDK that can track a real-life humanoid mannequin with passive trackers at the end of its joints, using ONLY a built-in mobile device camera. From a technical point of view, essentially I want to achieve the same functionality as presented in this video: https://www.youtube.com/watch?v=KyO5FNhoApw

If I could find an SDK that does this or at least does similar stuff, I could build upon that I think. The important part is to avoid using Kinect and only utilize the camera of the mobile device that runs the application.

Do you have any starting points in mind, maybe an SDK that might be helpful to check out?

Thank you so much in advance! L