ExpertiseLarge-scale system simulation

Today's military leaders must be prepared to answer a variety of questions in order to ensure that their units' response to a hypothetical hostile event is as efficient as possible. What type of simulation can be used to answer such questions? The answer to this question is large-scale simulation, the ability to simulate people, places, and things numbered not in the tens or hundreds, but in the thousands or tens of thousands.

For our purposes, large-scale simulation is a specific type of particle system. Particle systems were originally designed to simulate natural phenomena such as rain, fire, and smoke. In such systems, particles—the smallest units of simulation—are acted upon by external forces such as gravity and wind.

More recently, particle system techniques have been extended to include behaviors, where particles represent people or other animate entities and, in addition to being acted upon by external forces, can perceive their simulated environment and act within that environment based upon behavioral models. In such a system, particles with behaviors are often referred to as agents, and the system as a whole may be commonly referred to as a crowd system.