Boids (requires Javascript to work)

What is this?

This is a set of rules (that I didn't come up with) which are simple, but nonetheless result in organic-looking flocking behavior. I find the simulation pretty captivating to watch; it's one of many examples of something called emergent behavior, where complex patterns arise from simple rules. The Game of Life is another example of this. Anyway, here's all that's really going on:

• Cohesion: Each boid wants to move towards the flock, so we nudge each one towards the mean position of its neighbours.
• Separation: At the same time, the boids don't like running into each other or being too crowded. So, if they get too close, they fly away from each other.
• Adherence: The whole flock should fly together, so each boid steers itself such that it's flying in the same direction as its neighbours.

You can also tweak how strongly each of these three rules influence the boids. I'll add sliders at some point. If you want to see the code, it's accessible here. (Disclaimer: I am not good at writing Javascript.)