Open-Ended Behavioral Complexity for Evolved Virtual Creatures

In the 19 years since Karl Sims' landmark publication on evolving virtual creatures [22], much of the future work he proposed has been implemented, having a significant impact on multiple fields including graphics, evolutionary computation, and artificial life. There has, however been one notable exception to this progress. Despite the potential benefits, there has been no clear increase in the behavioral complexity of evolved virtual creatures (EVCs) beyond the light following demonstrated in Sims' original work. This paper presents an open-ended method to move beyond this limit, making use of high-level human input in the form of a syllabus of intermediate learning tasks-along with mechanisms for preservation, reuse, and combination of previously learned tasks. This method (named ESP for its three components: encapsulation, syllabus, and pandemonium) is employed to evolve a virtual creature with behavioral complexity that clearly exceeds previously achieved levels. ESP thus demonstrates that EVCs may indeed have the potential to one day rival the behavioral complexity- and therefore the entertainment value-of their non-virtual counterparts.