The crowd-animation system in character studio is designed to simulate the behavior of real-life crowds. A crowd simulation emulates real-life situations by animating delegates (helper objects that act as representatives). You give the delegates overall guidelines on how to behave, and the crowd simulation calculates their motion.
A crowd of bipeds
You set these guidelines by assigning behaviors to delegates. A behavior specifies a particular type of activity, such as moving toward an object in the scene, avoiding obstacles, following a path or surface, and so forth. You can combine multiple behaviors to create a rich and complex crowd simulation automatically. You can then link objects to delegates to complete the animation.
A crowd simulation can be used to animate bipeds, or to drive the use of mesh animation on objects linked to delegates. In addition, you can use cognitive controllers to tell delegates how to behave in varying circumstances.
This topic shows a basic procedure for creating and using a crowd system.
The crowd system in character studio uses two different helper objects: Crowd and Delegate. The first step in building a crowd simulation is the creation of these helpers. The Crowd helper serves as the command center for setting up and solving crowd simulations, while the Delegate provides a stand-in for each animated object in the crowd. You use the Crowd helper controls to animate the delegates, and then later you link objects to delegates to create the finished animation.
Delegate parameters define the nature of the delegate motion.
In the real world, different crowds exhibit diverse behaviors, and even members of the same crowd can conduct themselves in various ways. Included with the character studio Crowd system is an assortment of behaviors that let you simulate a range of crowd activities.
One of the purposes of behaviors is to move delegates in a particular direction over the course of the simulation.
An important part of crowd behavior is avoidance of obstacles. Think of an obstacle as anything that impedes a crowd member's progress. Examples of obstacles include walls, telephone poles, and fences, as well as other crowd members. Encountering such objects can cause avoidance behavior, which consists of any combination of slowing down, turning, and stopping.
You can use the Orientation behavior to change the direction in which a delegate moves, and the Speed Vary behavior to vary delegates' speed or make them stop moving altogether.
After you have set up behaviors for delegates, you must solve the simulation to generate keyframes on delegates. You solve the simulation by selecting the crowd object and clicking Solve in the Solve rollout.
You can link objects or bipeds to delegates to make them follow the simulated animation.
You can use the cognitive controller feature to cause crowd members to change behaviors during a simulation, depending on the circumstances. For example, a character could wander randomly until it comes within a certain distance of a target, at which point it could head straight for the target.
You can create advanced, complex crowd simulations with motion synthesis, which lets character studio adjust the simulation results dynamically to account for differing conditions. Two different forms of motion synthesis are available: one for non-bipedal crowds, and a second for the more exacting requirements of biped crowds.
Crowd animation lets you simulate the behavior of crowds of people, animals, or other beings parametrically, using several different types of objects. The topics that follow describe the user interface for setting up a crowd simulation.
