Simulating virtual human crowds with a leader-follower model

Although virtual humans have been an active research topic for many years, most research has focused on simulating various aspects of a humanoid instead of a crowd of people. We report our progress on generating collision free gross motions for multiple virtual crowds. Each virtual crowd consists of a leader and many followers. The leader is in charge of generating motions for its own group with the motions of other crowds taken into account. The followers use artificial life principles to follow the leader as it moves towards the goal. The high degrees of freedom involved in the crowd simulation system present a great challenge for gross motion planning. We adopt a decoupled path-planning approach, in which the paths being executed by other leaders become the motion constraint of the current leader under consideration. In addition, we take a unified view of search space to extend the planner to consider a whole crowd instead of just its leader. Experimental results show that our planner can efficiently generate satisfactory motions. We believe that such a planning system is a good addition to controlling groups of avatars in a 3D virtual environment.