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NASA Glenn has a lab where they have created a simple virtual-reality world using four 120 Hz CRT projectors and LCD shutter glasses. I was in some programs there, and got to meet the guy who puts this stuff together. There was also a remote with a three-axis accelerometer that could be used to interact with the game. This setup has been around for awhile, and I remember thinking about it when the Wii came out, because the user interface was very similar.

FYI, LCD shutter glasses are glasses with two LCDs as lenses, which are basically one pixel each. They receive a binary signal from an IR emitter connected to the computer or video source, which determines which lens is black and which one is clear.

Anyway, you could use LCD shutter glasses with a 120 Hz TV nowadays (the HD transition is causing them to become more common, especially because they enhance the picture quality of 24 fps movies) and use the same principle the glasses use, only instead of one lens darkening in each pair of glasses, both lenses in one pair would darken, then both lenses in the other pair would darken.

The problem with this situation is that you're only getting a 60 Hz refresh rate with darkness between, so the video quality suffers. Furthermore, you've gone to the trouble of developing a system that has everything present to enable the use of stereo gaming, but can't be used for it because head tracking only works for one person at a time, and dividing the refresh rate by the number of lenses (in this case, four) results in an unacceptably short amount of time for which the picture is displayed, followed by an unacceptably long amount of time when you're seeing nothing.