Implicit crowds: Optimization integrator for robust crowd simulation

Ioannis Karamouzas, Nick Sohre, Rahul Narain, Stephen J Guy

Research output: Contribution to journalConference article

23 Scopus citations


Large multi-agent systems such as crowds involve inter-agent interactions that are typically anticipatory in nature, depending strongly on both the positions and the velocities of agents. We show how the nonlinear, anticipatory forces seen in multi-agent systems can be made compatible with recent work on energy-based formulations in physics-based animation, and propose a simple and effective optimization-based integration scheme for implicit integration of such systems. We apply this approach to crowd simulation by using a state-of-the-art model derived from a recent analysis of human crowd data, and adapting it to our framework. Our approach provides, for the first time, guaranteed collision-free motion while simultaneously maintaining high-quality collective behavior in a way that is insensitive to simulation parameters such as time step size and crowd density. These benefits are demonstrated through simulation results on various challenging scenarios and validation against real-world crowd data.

Original languageEnglish (US)
Article number136
JournalACM Transactions on Graphics
Issue number4
StatePublished - Jan 1 2017
EventACM SIGGRAPH 2017 - Los Angeles, United States
Duration: Jul 30 2017Aug 3 2017


  • Crowd simulation
  • Implicit integration
  • Physics-based animation

Fingerprint Dive into the research topics of 'Implicit crowds: Optimization integrator for robust crowd simulation'. Together they form a unique fingerprint.

  • Cite this