Intuitive Crowd Behaviour in Dense Urban Environments using Local Laws 

CÚline Loscos, David Marchal, Alexandre Meyer

Submission to EGUK 2003


In games, entertainment, medical and architectural applications, the creation of populated virtual city environments has recently become widespread. In this paper we want to provide a technique that allows to simulate up to 10,000 pedestrians walking in real-time. Simulation for such environments is difficult as a trade off needs to be found between realism and real-time simulation. This paper presents a pedestrian crowd simulation method aiming at improving the local and global reactions of the pedestrians. The method uses a subdivision of space into a 2D grid for pedestrian-to-pedestrian collision avoidance, while assigning goals to pedestrians to make their trajectories smoother and coherent. Goals are computed automatically and connected into a graph that reflects the structure of the city and triggers a spatial repartition of the density of pedestrians. In order to create realistic reactions when areas become crowded, local directions are stored and updated in real-time, allowing the apparition of pedestrians streams. Combining the different methods contributes to a more realistic model, while keeping a real-time frame rate for up to 5,000 simulated pedestrians.



What we want to accomplish

Oxford Circus

Video capture of Oxford Circus. Streams of people are clearly visible in this dense area.

The simulation of behaviour


Video showing the behaviour of an agent (tracked green cell, leaving a trail behind). Each agent takes the colour of the goal it has to reach. Goals are represented by cubes and are connected by straight coloured lines. Arrows in blue are left by the agents and represent the stored direction that influences decision of following agents.

Integration of the behaviour in our city simulation system


Integration of the behaviour in the system. In grey, are represented the accessible area (pedestrian crossings and pavements).