Writing a program for face / body recognition and further tracking of objects on the face / body (sort of like snapchat)?

Question

Programming

Good afternoon. In programming, unfortunately, not a guru yet. Mostly 3D.
I want to create a program that determines where the body / arms / legs are, and later, when selecting an object (in the program), this object ``ate`` on the part where it was indicated in the program. For example - it recognizes the head - I choose a hat (in the program) - a hat on the head. But it happens in real time.
Where should you start studying? What to study? Or you can modify the source codes or so.

Answer 1

opencv

Answer 2

I have been working with opencv on nodejs. The library itself https://www.npmjs.com/package/opencv4nodejs#examples , you can see examples