Projective Multi-Agent Dynamics.

We introduce a crowd simulation method that uses a block coordinate descent solver reminiscent of projective dynamics approaches. Existing projective dynamics work focuses on simulating deformable materials - which makes us the first to incorporate crowds into such framework. We simulate agents as nodes in a mass-spring system, where springs are created dynamically to simulate different crowd phenomena. We propose novel projective solutions for such springs to emulate time-to-collision avoidance behaviors. Our method encapsulates the collective response of the crowd using implicit Euler integration, while a conjugate gradient solver efficiently resolves the resulting mass-spring linear system to enable the simulation of large-scale, emergent crowd behaviors.