Mediapipe

MediaPipe is a cross platform Framework for building machine learning pipelines for processing time-series data like video, audio, etc. Amongst many other possibilities it turns your webcam into a depth/tracking camera.

Full documentation can be found here https://developers.google.com/mediapipe/ 

There are various ways to get Mediapipe set up in your computer;

When using Touchdesigner, have a look HERE

But also, be sure to check out Gazebo, a HKU built OSC tool, that also runs Mediapipe.