Crowd simulation for virtual environments offers many challenges centered on the trade-offs between rich behavior, control and computational cost. In this paper we present a new approach to controlling the behavior of agents in a crowd. Our method is scalable in the sense that increasingly complex crowd behaviors can be created without a corresponding increase in the complexity of the agents. Our approach is also more authorable; users can dynamically specify which crowd behaviors happen in various parts of an environment. Finally, the character motion produced by our system is visually convincing. We achieve our aims with a situation-based control structure. Basic agents have very limited behaviors. As they enter new situations, additional, situation-specific behaviors are composed on the fly to enable agents to respond appropriately. The composition is done using a probabilistic mechanism. We demonstrate our system with three environments including a city street and a theater.

@Article{SGC04,
  author       = "Sung, Makyu and Gleicher, Michael and Chenney, Stephen",
  title        = "Scalable Behaviors for Crowd Simulation",
  journal      = "Computer Graphics Forum",
  number       = "3",
  volume       = "23",
  pages        = "519--528",
  year         = "2004",
  note         = "Proceedings {Eurographics} '06",
  ee           = "http://diglib.eg.org/EG/CGF/volume23/issue3/v23i3pp519-528.pdf",
  url          = "http://graphics.cs.wisc.edu/Papers/2004/SGC04"
}