3D worked well enough on TT3D, no headache but a gloomy picture. I'm guessing therefore that the system is vertically and horizontally polarised light for the two pictures and indeed my glasses seemed just like sunglasses.
I'd thought the recent proliferation was due to some new digital trickery but I saw polarised at Futuroscope, Poitiers, France fifteen years ago. Also there the much superior LCD glasses which blacked out the left and right lenses alternately in sync with the film showing L & R frames. Why all the fuss now?