> Motion is tracked using the laptop camera via optical flow and mapped to continuous control over dynamics, while the sound is generated in real-time.

No, it's a different method.

Author here. We checked for APIs like this at the time, but since approximately every laptop has a webcam, the cv approach is much more accessible. It would be a fun rewrite though; I’m sure polling this would be a few orders of magnitude more efficient. There was definitely lag if you ran the app on a very underpowered machine which did impact the “playability” of the velocity parameter.