1. T.J. Hartnett CSE 704 Seminar Dr. Miller Spring ‘11 EVOLVING CREATURES

2. AGENDA Creatures Structure Creatures “Nervous System” Genetic Algorithms ODE Problems (NaN and Normalization) The Linear Complexity Problem Future Work

3. CREATURES STRUCTURE Each “Limb” is a box with random size dimensions A Creatures Skeleton modeled as a graph Connections made with ball joints and hinge joints

4. CREATURES NERVOUS SYSTEM Neural Nodes Two inputs with random weights Add, Log, Integrate, Oscillate 20 Function total Each Limb had 6 Nodes associated with it Received input joint feedback and output as forces on limbs

5. GENETIC ALGORITHMS Random Initial Population of 100 creatures Fitness evaluation of motion The fastest survive and reproduce Reproduce by tweaking neural input weights, neural input/output connections, addition and removal of limbs

6. OPEN DYNAMICS ENGINE Models Rigid Body Dynamics in 3 Dimensions Includes Collision Detection World, Bodies, Mass, Geoms, dWorldStep Parallel?

7. PARALLELIZATION OF ODE Example Code….

8. LINEAR COMPLEXITY PROBLEM http://en.wikipedia.org/wiki/Linear_complementarity_problem Matrix M vector q LCP seeks vectors z and w which satisfy the following constraints w = M z + q W >= 0 z >= 0 (each component) W i z i = 0 M must be symmetric positive definite matrix (zTMz > 0 for all non zero real z vectors) ODE Problem with objects colliding, should be positive ODE ERP and CFM

9. REFERENCES "Evolving Virtual Creatures" K.Sims, Computer Graphics (Siggraph '94 Proceedings), July 1994, pp.15-22 "Evolving Virtual Creatures"