Events Calendar

CS Distinguished Lecture

Speaker: Dr. James O'Brien, UC Berkeley

Talk Title: Sparse Matrix Factorization, Mesh Modification, and Real-Time FEM Simulation

Abstract: This talk will discuss the use of dynamic remeshing and sparse matrix factorization in the context of real-time dynamics simulations. The first part of the talk will focus on two systems that have been developed for specific applications: destructible environments in "Star Wars: The Force Unleashed" and interactive modeling of prostate brachytherapy. Although dynamic remeshing is often dismissed as impractically slow, in both cases it plays a key part to making the simulations work effectively in a real-time setting. The second part of the talk will focus on an incremental update method for the Cholesky factors of sparse matrices that out-performs standard iterative methods for solving elastodynamic problems. The factors are not recomputed at each time step, but the nonlinearities that normally compel refactoring are not ignored either. Instead, the algorithm makes local incremental updates to the Cholesky factors to maintain error limits on the solution. The results presented will include captured footage from the live game, comparisons of simulated needle insertion to footage with gel tissue phantoms, and demonstrations of the sparse direct solver on large meshes.

Biography: James F. O'Brien is an Associate Professor of Computer Science at the University of California, Berkeley. His primary area of interest is Computer Animation, with an emphasis on generating realistic motion using physically based simulation and motion capture techniques. He has authored numerous papers on these topics. In addition to his research pursuits, Prof. O'Brien has worked with several game companies on integrating advanced simulation physics into game engines, and his methods for destruction modeling were recently used in the film Avatar. He received his doctorate from the Georgia Institute of Technology in 2000, the same year he joined the Faculty at U.C. Berkeley. Professor O'Brien is a Sloan Fellow and ACM Distinguished Scientist, Technology Review selected him as one of their TR-100, and he has been awarded research grants from the Okawa and Hellman Foundations. He is currently serving as ACM SIGGRAPH Director at Large. http://obrien.berkeley.edu/

Host: Prof. Jernej Barbic, USC

Location: Seaver Science Library (SSL) - 150

Audiences: Everyone Is Invited

Contact: Kanak Agrawal