A huge challenge is to simulate tens of thousands of agents in real-time where they pro-actively and realistically avoid collisions with each other and with obstacles present in their environment, especially near narrow passages where cooperative behavior is required. This environment contains semantic information, such as roads or dangerous areas, is usually three-dimensional and can dynamically change.

We study how we can automatically create a data structure that represents the walkable surfaces in virtual environments, and how it can be updated dynamically and efficiently when it changes. We refer to this structure as a navigation mesh. This mesh enables efficient crowd simulation, which is our next topic of research. We study and develop a crowd simulation framework and its components, which ranges from global planning to local animation. We create models for realistic crowd behaviors, which includes studying how people and groups of people move and avoid collisions in such environments, based on agent profiles and semantics.

We continuously integrate our research into our UU Crowd simulation software which is used by many research institutes and companies. We run simulations in realistic environments and game levels to study the effectiveness of our methods.


Click on the pictures for more information.

  • Summerschool Utrecht - Introduction to Complex Systems

    I'll give a lecture on crowd simulatation on the SUMMERschool Utrecht 2017 themed Introduction to Complex Systems. The summer school takes place from 3 to 7 July in 2017.
    The motions of the crowd in the Love parade is an example of a complex system.
  • Summerschool Utrecht - Multidisciplinary Game Research

    We'll give a masterclass on crowd simulation using our Unity3D plugin. The summer school takes place from 21 to 25 August in 2017.
    A crowd in Unity3D generated by our crowd simulation plugin.


  • Bessensap 2007

    I've given a presentation during Bessensap 2017, which is organised by NWO and the Vereniging voor Wetenschapsjournalistiek en –communicatie Nederland. The presentation is entitled (in Dutch): De meute ontrafeld: simulatie en beheersing van mensenmassa's.
    Bessensap 2017.
  • Boosting academic start-ups

    We've discussed how barriers can be taken away which are experienced by start-ups when they go from academia to their spin out. We hope to increase the potential of knowledge utilisation from within universities under the guidance of StartupDelta and Constantijn van Oranje.
    Discussions about start-ups and knowledge utilization.
  • PhD defense Wouter van Toll

    My PhD student, Wouter van Toll, has successfully finished his PhD thesis entitled 'Navigation for Characters and Crowds in Complex Virtual Environments' at Utrecht University.
    Phd thesis of Wouter van Toll: Navigation for Characters and Crowds in Complex Virtual Environments.
  • Research finds its way to society via UtrechtInc

    We followed a 4 months program at incubator UtrechtInc to build the blueprint of our startup (in formation), uCrowds. Here, we offer a software engine for simulating crowds in big infrastructures, events or computer games. We presented ourselves in front of an independent jury and audience, and obtained the possibility to get a starting capital of 18K Euro.
    Our startup, uCrowds, meets prince Constantijn. We offer a software engine for simulating crowds in big infrastructures, events or computer games.
  • Collaboration Utrecht University and Movares

    We signed a collaboration agreement about crowd simulation between Utrecht University and Movares. "It is not only about safety, but also about experience."
    Collaboration Utrecht University and Movares.
  • Visit EU ambassadors

    We have given an augmented-reality crowd simulation demo to all EU ambassadors and policy makers who paid a visit to Utrecht on May 20, 2016. The demo displays a simulation inside a part of this city. Users can interact with the simulation by inserting or removing illuminated blocks. This allows them to play with different scenario's in an interactive and intuitive way.
    Visit EU ambassadors
  • Utrecht crowd simulation software enters market

    We will develop a crowd simulation engine for game developers and companies specialized in simulating large flows of people. We have recently received a grant of 150,000 Euros from the STW technology foundation's Demonstrator Programme. The simulation software is much more advanced than the packages currently available on the market. In a conjunction with consulting and engineering bureau Movares the software was used by the city of Utrecht to prepare for the start of the Tour de France.
    Utrecht crowd simulation software enters market
  • Virtual polka dots predict spectator flows for Grand Départ

    The Grand Départ of the Tour de France is expected to draw anywhere from 600,000 to 800,000 spectators to Utrecht. Simulations in a virtual Utrecht support the municipal government in planning the surroundings of the cycling course and testing the prognoses for the flows of the spectators. These innovative simulations in an unprecedentedly detailed virtual world were the result of collaboration between computer scientists at Utrecht University and the engineering and consulting bureau Movares.
    Virtual polka dots predict spectator flows for Grand Départ

About me

I am an assistant professor at the Virtual Worlds group in the Department of Information and Computing Sciences at Utrecht University in the Netherlands. There, I obtained my PhD on sampling-based motion planning techniques. In addition, I studied quality aspects of paths and roadmaps. My current research focuses on path planning and crowd simulation in games and virtual environments. I currently teach a course on crowd simulation. I have organized the Creative Game Challenge and I am one of the cofounders of the annual Motion in Games conference.

We have created a software package for efficient crowd simulating in multi-layered 3D dynamic environments. We use the package for e.g. preparations of the Grand Départ of the Tour de France, and for evacuation studies in the Noord/Zuid-lijn in Amsterdam.