Searching for references for markerless motion capture, how is it done

Hi all,

I am looking for details for the models used in motion capture that only leverages images, so photogrammetry.

There are a few companies doing this

Developers.move.ai theiamarkerless.ca

I would like to try this with animals. I assume the AI part helps with the point cloud interpretation but looking for a bit more context before starting my deep dive.

Really cool tech!