Distributed Simulation of Crowds with Groups in CrowdSim Simulating large crowds of individuals is socially important, e.g., for developing and studying evacuation or rescuing in dangerous situations. Such simulations remain complex due to the scalability challenge: simulating thousands of virtual characters is computationally expensive, especially when taking into account psychological factors and groupspecific behavior that play a crucial role, e.g., in panic situations and highly crowded environments. In this paper, we make two new contributions: 1) we extend the HiDAC agentbased modeling approach with the aspects of group formation and movement, and 2) we implement our approach within the CrowdSim system, including the possibility to distribute the simulation process across several compute servers for better performance. We report experimental results on scaling the distributed simulation of a realworld evacuation scenario in a building using several compute servers.

Do people follow the crowd in building emergency evacuation? A crosscultural immersive virtual realitybased study Abstract   This study aimed to examine the influence of crowd flow on human evacuation behavior during building fire emergencies, when evacuees perceive high uncertainty in the environment and experience mental stress. Evacuation experiments were conducted in an immersive virtual metro station, in which each participant was presented with one of three different patterns of crowd flow and asked to complete an evacuation task. The patterns of crowd flow were represented by nonplayer characters that split differently at each wayfinding decision point in the metro station. The experiments were conducted in Beijing, Los Angeles and London. The results showed that uneven splits of crowd flow motivated participants under mental stress to follow the majority of the crowd. This influence of crowd flow was generally consistent over the course of evacuation, and such consistency could be reinforced by stronger directional information conveyed by the crowd flow as well as positive feedback from the outcomes of previous wayfinding decisions. The results also indicated that the influence of crowd flow was significant in all three cultures represented by the three cities, however, the impact of culture on how participants would respond to the directional information conveyed by the crowd flow was insignificant.