Can I use a virtual camera with Head Tracking?

The TLDR is that we do not recommend using virtual cameras with Head Tracking; you should always select a physical web camera instead. But if you're interested in knowing more, here's why:

Head Tracking feature uses a camera to detect your head movements, modify the game's audio accordingly and send it to your headsets so that you have the impression of being in the game! 

One of the most critical aspects of Head Tracking is ensuring that the sound reacts in real-time to your head movements. For that purpose, we minimize any item that can cause latency to the audio response, which would end up ruining your immersive experience. A virtual camera is created from a software application. So, compared to a physical web camera, the virtual camera video feed has some additional delay compared to the one coming directly from the web camera. As little as this delay will be, it will have a negative impact on the Head Tracking perception.