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.


  • 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.
  • Utrecht crowd simulation software enters market

    We will develop a crowd simulation engine for game developers and companies specialised 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.
  • 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.

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.

I supervise three PhD students and many MSc students. 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/Zuidlijn in Amsterdam.