Top  Previous  Next

The first method of generating three-dimensional images is called "Two Color Mode." Technically, it also called "Anaglyphic" 3D. In this mode, two images of the cave, each in a different color, are plotted on top of each other. These images are viewed through special glasses that have lenses that match the image colors. Each lens only allows a single color to pass. For example, if you view red and blue lines with a red lens, only the red line will be visible. Because the red lens only allows red light to pass, blue lines will appear to be black. Thus, if background is black, the blue lines will disappear. By having a different color lens for each eye, each eye sees a different image.


3D Glasses. In order to view two-color images, you must have a pair of two-color glasses. You can sometimes find them in toy stores, hobby shops or as a part of various games, TV shows and magazine promotions. They are supplied with every COMPASS registration and extra pairs are available from


When you look at the screen with the two-color glasses on, you should see a three-dimensional image of the cave. It may take a few seconds for your eye to adjust to the image, before you can see the 3D effect. If you have trouble seeing the stereo effect, or have any other problems, refer to the Stereo Viewing Tips section.


Reversed Images. If the 3D effect seems to be backward so that distant parts of the cave appear to be close and vice versa, reverse the glasses. You get the best 3D effect if you use a black background and the color red for your right eye and blue for your left eye. (If your left eye is dominant, reverse the colors.) I find that viewing the cave in profile, with the plot pitched slightly toward the screen, gives the best effect. Also, if you put the Viewer in Hidden Refresh mode, and you use small increments, you get a very powerful illusion of actually moving around a three dimensional image of the cave.


Printing Two-Color Images. You can also print two-color images but it works a little differently. On a black background, a red lens makes the blue lines disappear. But on white background, a red lens makes the red line blend with the background and blue lines appear black. As a result, you either have to reverse glasses or reverse the color scheme.. It also helps to lighten the colors when printing.