Interlocked chains of spherical pearls move along 3D Lissajous curves, like the two chains of a zipper. In a 2D projection, it is often difficult to understand the spatial relationships. For a better impression, we use two stereoscopic perspective pictures.
This Demonstration is an example of a simple method to realize spatial vision without the help of glasses. You must squint so that the right eye looks at the left image and the left eye looks at the right image. To do this, look at one finger half the distance between eyes and screen.
Let the process run in either forward or backward mode to see a nice animation. 3D computer graphics make it possible to expand a division of fine arts: that of mobiles. The resulting objects are no longer bound to physical laws, but give a realistic view and allow spatial presentations that are are not possible in reality. This allows you to have a special kinematic impression, characterized by high aesthetic value. The free-floating beads are an example of such an entirely new experience.
H. W. Franke, Computer Graphics, Computer Art, London: Phaidon, 1971.
H. W. Franke, Animation mit Mathematica, Berlin: Springer, 2002.