tailieunhanh - The Electric Sheep Screen-Saver: A Case Study in Aesthetic Evolution

More than eighty years later, it is not so much a utopian use of technical innova- tions that marks the current trend in lifestyle advertisement, but – on a deeper level – an aestheticisation of everyday experience that connects the commer- cials discussed here to the avant-garde movement of the 1920s. | The Electric Sheep Screen-Saver A Case Study in Aesthetic Evolution Scott Draves Spotworks San Francisco CA USA Abstract. Electric Sheep is a distributed screen-saver that harnesses idle computers into a render farm with the purpose of animating and evolving artificial life-forms known as sheep. The votes of the users form the basis for the fitness function for a genetic algorithm on a space of fractal animations. Users also may design sheep by hand for inclusion in the gene pool. This paper describes the system and its algorithms and reports statistics from 11 weeks of operation. The data indicate that Electric Sheep functions more as an amplifier of its human collaborators creativity rather than as a traditional genetic algorithm that optim izes a fitness function. 1 Introduction Electric Sheep 5 6 was inspired by SETI@Home 1 and has a similar design. Both are distributed systems with client server architecture where the client is a screen-saver installable on an ordinary PC. Electric Sheep distributes the rendering of fractal animations. Each animation is 128 frames long and is known as a sheep. Besides rendering frames the client also downloads completed sheep and displays them to the user. The user may vote for the currently displayed sheep by pressing the up arrow key. Each sheep is specified by a genetic code comprised of about 160 floating-point numbers. The codes are generated by the server according to a genetic algorithm where the fitness is determined by the collective votes of the users. This is a form of aesthetic evolution a concept first realized by Karl Sims 9 and analyzed by Alan Dorin 3 . This is how Electric Sheep worked until March 2004 when a new source of genomes appeared Apophysis 10 . Apophysis is a traditional stand-alone Windows GUI to the sheep genetic code primarily intended for still-image design but useful for key-frame animation. Besides a traditional direct manipulation interface where the user drags sliders and types numbers into .