Viewing Stereo
Active Stereo
Users of active stereo systems wear special glasses (sometimes called shutter glasses) that can open and close shutters over the left and right eyes very rapidly under computer control. The computer presents the left eye image on the shared screen and simultaneously opens (closes) the left (right) eye shutter. It then displays the right eye image and simultaneously opens (closes) the right (left) eye shutter. Cycling this process at typical display refresh rates gives the user the sensation of seeing a true 3D scene in front of their eyes.
While reproducing the effect of a true 3D scene quite well, active stereo approaches do suffer from some serious drawbacks. Most notably, the glasses tend to be fairly expensive, and they can be somewhat fragile and bulkier than those used for passive stereo.
