From: Bruce Cohen Subject: Re: Polarized light 3D systems: info wanted Date: 17 May 91 19:54:37 GMT Organization: Tektronix Inc. In article <1991May17.030937.9450@milton.u.washington.edu> buckland@ucs.ubc.ca (Tony Buckland) writes: >>Enclosed is the posting I planned to put on nn. > > The traditional polarized-light 3-D system is appropriate for > movies, but not for systems involving viewing computer displays. > In the case of movies, two separate streams of light are directed > at the screen, one containing the right-eye image and one the > left-eye image. They pass through separate polarizing filters. > Each audience member's goggles contain correspondingly-oriented > polarizing filters so that only the right-eye image reaches the > right eye, and only the left-eye image the left eye, even > though both photon streams are bouncing off the same place on > the theatre screen. > > The key is the polarization of the photon stream which each eye > sees. Achieving this with a computer display would involve [ lines missing ? ] > is to view. To make a similar scheme work with left-eye and > right-eye images coming from the same display would involve > having a mechanical device rotating 90 degrees in front of the > display every 1/60th second or faster, while the displayto ows > alternating views for each eye. This is a big mechanical [ lines missing ...] There has been at least one 3D viewing system for computer displays on the market which does very well with the simple glasses and which does *not* use a mechanical shutter. Rather, there's an LCD shutter, as you describe for the synchronized glasses system. This shutter system was developed by Tektronix and marketed on their 3D terminals adnd workstations. Now that Tek has introduced a Pex terminal I expect that they'll be putting the shutter on it some day. Note that though I work for Tek, I no longer work in the graphics division, and have no official or unofficial knowledge of product plans; I'm just speculating on my own hook. The displays the system was used on put up 60 frames/sec, alternate frames for each eye with the polarization rotated by the shutter. I've used the shutter on several different displays (I worked on some of the internal display firmware for 3D interaction using tablets and dialboxes and such), and the stereo effect seemed quite good to me. At least I was able to do reasonably accurate tracking of a cursor in 3D without needing other depth cues like depth shading or color desaturation. -- ------------------------------------------------------------------------ Speaker-to-managers, aka Bruce Cohen, Computer Research Lab email: brucec@rl.labs.tek.com Tektronix Laboratories, Tektronix, Inc. phone: (503)627-5241 M/S 50-662, P.O. Box 500, Beaverton, OR 97077