5 Generative Audiovisual Systems

The above sections have discussed several genres of audiovisual software artworks, including systems that use music to generate aesthetic or analytic visualizations, artworks that map real-world data signals to graphics and sound, and artworks that use human performances to govern the synthesis of animation and music. A fourth significant genre of audiovisual software artworks, known as generative artworks, produces animations and/or sound autonomously—from their own intrinsic rule-sets. These rules may range from trivial forms of randomness to sophisticated algorithmic techniques that simulate complex organic processes or that even implement artificial intelligence models of visual and musical composition. One influential example of such an autonomous artwork is Scott Draves’s Bomb (1993–1998), a free software system that produces fluid, textured, rhythmic, animated, and generally non-representational visual music.^[29] Bomb uses recursive and nonlinear iterated systems, such as cellular automata algorithms (often used to simulate animal population behavior), reaction-diffusion equations (used to simulate organic pattern formations, such as leopard spots and zebra stripes), and video feedback. According to Draves, one of the most important innovations in Bomb was the idea of having multiple CA [cellular automaton] rules interacting with each other, which allowed the program to generate and evolve a truly vast range of organic graphic configurations.^[30]

Whereas Bomb is silent, Antoine Schmitt’s Nanoensembles (2002) uses simple generative techniques to produce both sound and animation simultaneously.^[31] Small animated visual elements move back and forth across the canvas in Nanoensembles, each at their own rate, each producing a simple looping sound whose volume is related to their speed and position. Because each element has its own unique cycle period, the motions of each eventually go out of phase—as do the sounds of each. The result is an ever-changing and effectively endless audiovisual composition.