Here is what I have found after researching motion tracking in Touchdesigner
Please let me know if there are any others option I missed.
Software only:
Script TOP
Blob tracking
Silhouette
Using Google mediapipe via python: Face tracking , fingers etc
Complicated to set up and modify for beginners and sometimes quite resource heavy
MediaPipe in TouchDesigner 1 – Magic & Love Interactive -in-touchdesigner-1/
ZIGCAM iOS app
Using hardware dependent options:
Nvidia RTX:
Intel RealSense $259+
https://docs.derivative.ca/RealSense
Kinnect cheap off ebay but nearly 10 years old (must be windows compatible setup)
https://docs.derivative.ca/Kinect
Azure Kinect DK current but expensive Microsoft version $399