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Colloquia

Self-Organizing Primitives for Automated Shape Composition

Dr. David E. Breen
Drexel University

September 11, 2008
Carnegie 112, 4:00 p.m. to 5:00 p.m.
Refreshments at 3:30 p.m.

Abstract:

Motivated by the ability of living cells to form into specific shapes and structures, we present a new approach to shape modeling based on self-organizing primitives whose behaviors are based on cell biology and derived via genetic programming. The key concept of our approach is that local interactions between the primitives direct them to come together into a macroscopic shape. The interactions of the primitives, called Morphogenetic Primitives (MPs), are based on the chemotaxis-driven aggregation behaviors exhibited by actual living cells. Here, cells emit a chemical into their environment. Each cell responds to the stimulus by moving in the direction of the gradient of the cumulative chemical field detected at its surface. MPs, though, do not attempt to completely mimic the behavior of real cells. The chemical fields are explicitly defined as mathematical functions and are not necessarily physically accurate. The explicit mathematical form of the chemical field functions are derived via genetic programming (GP), an evolutionary computing process that evolves a population of functions. A fitness measure, based on the shape that emerges from the chemical-field-driven aggregation, determines which functions will be passed along to later generations. This talk will describe the cell interactions of MPs and the GP-based method used to define the chemical field functions needed to produce user-specified shapes from simple aggregating primitives.

Bio:

Dr. David E. Breen is currently an Assistant Professor in the Computer Science Department of Drexel University. Before coming to Drexel he held research positions at the California Institute of Technology, the European Computer-Industry Research Centre, the Fraunhofer Institute for Computer Graphics, and the Rensselaer Design Research Center. His research interests include geometric modeling, scientific visualization, medical image analysis, and biological simulation. He has authored or co-authored over 70 technical papers, articles and book chapters on these subjects. He is the co-editor of the book "Cloth Modeling and Animation". Breen received a BA in Physics from Colgate University in 1982. He received MS and PhD degrees in Computer and Systems Engineering from Rensselaer Polytechnic Institute in 1985 and 1993.

Hosted by: Dr. Barb Cutler (x3274)

Last updated: September 3, 2008