Cohesion, alignment, and separation

• Buckland talks about these three things.
• Separation is how far objects are from each other. To avoid crashing, objects want to maximize separation.
• Alignment is the direction objects are pointing in. If two (or 27) objects are pointed in the same direction, they're aligned. Note that if you are moving at the same speed, aligned objects don't crash into each other.
• Cohesion is how closely together objects are. It's pretty much the reverse of seperation. Agents want to be cohesive because it can protect them from exterior forces (pigeons from hawks, and penguins from the wind).