A realistic, natural-looking flocking behavior (for example birds, antelope, or bats) can be developed by creating collections of objects with the following four simple rules:
- Separation: Avoid getting too close to neighbors.
- Avoid obstacles: Turn away from an obstacle immediately ahead.
- Alignment: Move in the general direction the flock is heading.
- Cohesion: Move toward a location in the middle of the flock.
Each member of the flock acts independently but needs to know about the current heading and location of the members of its flock. This recipe will show you how to create a scene with two flocks of cubes: one flock of green cubes and one flock of yellow cubes.
To keep things simple, we won't worry about separation in this recipe:
Figure 10.16 – Example of controlling object group movement through flocking