CAVE style VR suffers from the same problem if you don't want to use stereoscopic shutter glasses. You can track one user's head position and update the render

CAVE style VR suffers from the same problem if you don't want to use stereoscopic shutter glasses. You can track one user's head position and update the renderer's camera accordingly, but with multiple users you can't do that without shutter glasses. Even with shutter glasses, I'd think there must be some limit on how many users you could have at once without irritating flickering; with 3 users and six different perspectives to render, both displays on an individual user's glasses would be opaque 2/3 of the time, and each eye would see an image for 1/6 of every unit time.