The EPlex group specializes in several key areas:

  • Hypercube-based Neuroevolution of Augmenting Topologies (HyperNEAT): HyperNEAT  is a method for evolving neural networks with large numbers of nodes and connections that was created here in the EPlex group at UCF.  It uses connective CPPNs to generate regular connectivity patterns that can be produced at scalable resolutions.  HyperNEAT in effect  turns the original NEAT into a special kind of indirect encoding for large-scale neural networks.  It exploits the fact that connectivity patterns are isomorphic to spatial patterns in a higher-dimensional space.

  • Group Behavior and Multiagent Learning: In natural evolving populations there is often group interaction during evolutionary evaluation (i.e. during life).  This interaction often leads to complex role assignment and cooperation.  We are also exploring multiagent learning through the new multiagent HyperNEAT algorothm invented at EPlex..

  • Novelty Search: Novelty search is a new algorithm invented at EPlex that abandons the idea of searching for higher fitness with respect to an objective and instead searches for novel behavior alone.  The surprising effect of such a process is that it often evolves objectively superior behaviors to evolution that is rewarded explicitly for searching for the objective!  Novelty search raises important philosophical questions about the basis of evolutionary progress and also opens new opportunities for evolutionary algorithms.
  • Complexification: Complexification is the process through which new genes are added to the genome over generations, thereby gradually increasing the dimensionality of the search space, and hence the potential complexity of the phenotypes.  Complexification is a means to find solutions in high-dimensional spaces even if it is not practical to start searching directly in such spaces.

  • Indirect Encoding, Developmental Encoding, and Gene Reuse: If genes can be reused in the mapping between genotype and phenotype, then the genotype space can contain far fewer dimensions than the phenotype space, making the search for high-level complexity tractable.  For example, the 30,000 genes in the human genome produce a brain with 100 trillion connections through a process of development.

  • Compositional Pattern Producing Networks (CPPNs): CPPNs are a novel abstraction of biological development developed here in the EPlex group.


  • NeuroEvolution of Augmenting Topologies (NEAT): The NEAT method (created by EPlex director Kenneth Stanley) is the first principled implementation of complexifying evolution.  We utilize the general principles of NEAT as an underlying methodology for our evolutionary experiments.

NEAT network

  • Artificial Neural Networks (ANNs): Our long-term goal is to evolve extremely complex ANNs.  Through complexification and indirect encoding an intermediate goal is to evolve useful ANNs with tens of thousands of neurons or more.

  • Music Generation.  EPlex is developing new methods for generating music and assisting musicians based on the scaffolding theory introduced in NEAT Drummer.

  • Competitive Coevolution: In sophisticated competitive domains in which it is difficult to formalize a fitness function, the only way to spark a chain of increasing evolutionary complexity may be through a direct competition among evolving individuals.

  • Video games, simulation, rtNEAT, and cgNEAT: The real-time NEAT algorithm can be used to evolve intelligent non-player-characters (NPCs) and novel content in video games and training applications in real time.  The newer cgNEAT algorithm evolves video game content to satisfy the players, as demonstrated in Galactic Arms Race . As new methods for evolving complexity are developed, they can be applied to video games and simulation by integrating them with such approaches in the future, creating opportunities for new kinds of games.  The pictures below show the NERO video game, which uses rtNEAT to allow players to train robots in real time to perform tasks, and Galactic Arms Race, which evolves its own unique spaceship weapons.

     NERO  GAR Screenshot