Wei Xiang, He Wang, Yuqing Zhang, Milo K. Yip and Xiaogang Jin
Realistic crowd simulation has been pursued for decades, but it still necessitates tedious human labour and a lot of trial and error. The majority of currently used crowd modelling is either empirical (model-based) or data-driven (model-free). Model-based methods cannot fit observed data precisely, whereas model-free methods are limited by the availability/quality of data and are uninterpretable. In this paper, we aim at taking advantage of both model-based and data-driven approaches. In order to accomplish this, we propose a new simulation framework built on a physics-based model that is designed to be data-friendly. Both the general prior knowledge about crowds encoded by the physics-based model and the specific real-world crowd data at hand jointly influence the system dynamics. With a multi-granularity physics-based model, the framework combines microscopic and macroscopic motion control. Each simulation step is formulated as an energy optimization problem, where the minimizer is the desired crowd behaviour. In contrast to traditional optimization-based methods which seek the theoretical minimizer, we designed an acceleration-aware data-driven scheme to compute the minimizer from real-world data in order to achieve higher realism by parameterizing both velocity and acceleration. Experiments demonstrate that our method can produce crowd animations that are more realistically behaved in a variety of scales and scenarios when compared to the earlier methods.