This icosahedron is constructed as a stereopair, with the red image designed to be viewed with your left eye and the blue image with your right. (You'll need a pair of red/blue 3-D glasses or goggles to appreciate the effect.) The Picture, Horizon, and Ground points control the perspective projection of the 3-D model, using Cathleen Sanders's mechanical drawing techniques.
The Right and Left points control the degree of disparity between the projected stereo images. Dragging them far apart simulates the binocular vision of a rhinoceros, and dragging them close together the vision of a mouse. When the two points are coincident, the stereopair reduces to a monocular projection.
William F. Finzer, November, 1993, 1997