FYI Syphon (which is used to link OBS to CamTwist) stop working since MacOS 10.15 since their "hack" that was making the whole thing work, stopped working.

For "light" shenanigans, install: http://camtwiststudio.com/

On the mac, Version 3.4.3 is working fine with Catalina (10.15.4).

It adds in a virtual camera interface and you can configure a pipeline of sources or pipelines.

An easy setup is: - Webcam (set to FaceTime HD Camera) - Matrix effect

A more complex one is: - Add webcam - Select "movie" but press PIP - In the PIP Movie settings, "Swap with Video Source" - Mess with the Chroma key settings (you need a solid background color) for Chroma to work. I use a bed sheet :)

I'll circle back with the OBS/Syphon Pipeline/CamTwist shortly as it was much more involved!

yes, seconding this