Publication details

Interaction Fields: Intuitive Sketch-based Steering Behaviors for Crowd Simulation
Adèle Colas, Wouter van Toll, Katja Zibrek, Ludovic Hoyet, Anne-Hélène Olivier, Julien Pettré
Computer Graphics Forum 41(2), 2022.
Received a Best Paper Award Honorable Mention (Eurographics 2022).
Inria HAL page - Full paper (PDF)

Also published as:
Interaction Fields: Sketching Collective Behaviors
Adèle Colas, Wouter van Toll, Ludovic Hoyet, Claudio Pacchierotti, Marc Christie, Katja Zibrek, Anne-Hélène Olivier, Julien Pettré
Poster abstract at 13th ACM SIGGRAPH Conference on Motion, Interaction and Games, 2020.


The real-time simulation of human crowds has many applications. In a typical crowd simulation, each person ('agent') in the crowd moves towards a goal while adhering to local constraints. Many algorithms exist for specific local 'steering' tasks such as collision avoidance or group behavior. owever, these do not easily extend to completely new types of behavior, such as circling around another agent or hiding behind an obstacle. They also tend to focus purely on an agent's velocity without explicitly controlling its orientation.

This paper presents a novel sketch-based method for modelling and simulating many steering behaviors for agents in a crowd. Central to this is the concept of an nteraction field (IF): a vector field that describes the velocities or orientations that agents should use around a given 'source' agent or obstacle. An IF can also change dynamically according to parameters, such as the walking speed of the source agent. IFs can be easily combined with other aspects of crowd simulation, such as collision avoidance. Using an implementation of IFs in a real-time crowd simulation framework, we demonstrate the capabilities of IFs in various scenarios. This includes game-like scenarios where the crowd responds to a user-controlled avatar.

We also present an interactive tool that computes an IF based on input sketches. This IF editor lets users intuitively and quickly design new types of behavior, without the need for programming extra behavioral rules. We thoroughly evaluate the efficacy of the IF editor through a user study, which demonstrates that our method enables non-expert users to easily enrich any agent-based crowd simulation with new agent interactions.

BibTeX citation

    author = {Colas, A. and van Toll, W. and Zibrek, K. and Hoyet, L. and Olivier, A.H. and Pettr\'e, J.},
    title = {Interaction Fields: Intuitive Sketch-based Steering Behaviors for Crowd Simulation},
    journal = {Computer Graphics Forum},
    year = {2022},
    volume = {41},
    number = {2}