Behavioral Animation Procedural Animation Type Behavioral Animation Introduced
Behavioral Animation Procedural Animation Type?
Behavioral Animation • Introduced by C. Reynolds (1987) • Animating many things at one time – A group of the same species (flock of birds, school of FISH) – “boids” Instead of animating individually, specify rules
Behavioral Animation Two main forces control group: 1. Collision avoidance- each member must avoid collision with other members and the environment 2. Tendency toward group centering (staying together) • • Implies knowing about other members Localized, not global so that flock splitting can occur
Additional Forces • Velocity matching of neighboring boids (like merging on a freeway) • Attraction/repulsion (like bees attracted to sweets) • Behaviors – Migration – follow-the leader (leader has pre-scripted path) – Predator-prey(two species or additional actor)
Resultant • To determine resultant vector, don’t use averaging. • Instead, use priority allocation based on finite (normalized) resource A boid is moving through a force field. Assume that the boid’s trajectory is determined 75% from current trajectory and 25% from external forces. If the current trajectory is (1, 1, 1) and the external force is (0, 2, 0), what is the next trajectory after one time step?
Perception • Boid aware of itself and 2 -3 neighbors • See what’s ahead of it within limited field of view – Distance visible in front is limited – Influenced by objects (obstacles, force fields) based on distance & size
Next Step • Massive/crowd animation
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