artificial life

Chapter 6: Genetic Programming

6.6 Karl Sims

Perhaps the most vivid use of Genetic Programming as a form of Artificial Life is the work of Karl Sims. Sims was a student at MIT who began as a graphic designer. He developed several techniques for creating graphics using Genetic Algorithms and Genetic Programming. One of the first projects that Sims developed using genetic programming was a system that took user input to determine the most fit of a series of images. The user was presented with a population of computer-generated images and chose the most interesting images to generate a new population. In this project the user's aesthetic taste was the fitness function for the genetic algorithm. It is this project that has been emulated in the major application of this project [Sims, 1991].

After working with flat images, Sims moved on to 3D graphics by evolving virtual creatures. The creatures are placed in a virtual environment and their fitness is determined by their ability to complete certain tests. The simplest of these tasks requires the creatures to use some form of locomotion of move themselves through the environment. In some environments the creatures are made to swim in order to survive while other environments put the creatures on solid ground so that they would learn to walk. The fitness function of the creatures is a value proportional to the distance the creature traversed. Using this technique Sims is able to create several creatures that use novel techniques for locomotion. Sims continued to experiment with the creatures, having others specialize in different abilities such as jumping and following [Sims, 1994].