The is done as though the camera points is at the crest of the pyramid. This is simple enough to do, and can be done using two multiplies, two adds, and two divides. For a given point to be correctly projected for a given eye, it must first be transformed to that eye's view space. Figures 3a and 3b show the left and right eye images generated using this method. Due to the fact that, when using stereoscopic projection, each eye needs to see a different image, some sort of special display hardware is needed.
Typical hardware ranges from the very cheep to the very very expensive.
This method involves covering one eye with a red filter and the other with either a green or a blue filter. This way the lenses will prevent either eye from seeing the other eye's image. That is, you get one hue that can vary intensities. Another method, that is a bit more expensive and can be dangerous, is the use of shutter glasses. Anyone who owned a Sega Master System in the 80's know what this device is.