Dancing with Friends and Enemies: Swarm Intelligence in Boids
Dancing with friends and enemies: boids' swarm intelligence
A playful experiment turns 1,000 particles into dancers, each with a randomly chosen friend and enemy, moving closer to the center, toward friends, and away from enemies. The simple rules produce mesmerizing swirling patterns, illustrating how macro-scale swarm behavior emerges from local interactions. The post includes code, animations, and variations like 3D and ring configurations.
The description of the system as a dance was an attempt to explain the swirling pattern on the screen without using mathematical language.
- markstock
The tweaks that SW included are pretty common to similar simulations:
1) the attraction-repulsion pair is typical of "boids" simulations, and also features in the Lennard-Jones forces acting in atoms (albeit with different powers on the decay rate);
2) making the force drop to zero for particle-particle distances approaching zero is effectively treating each particle as a "cloud" and not a singular point, it's called "regularization" in vortex particle methods and "Plummer softening" in gravitational methods; it's primary benefit is with SIMD and parallelization by removing the need for a (i != j) conditional; and
3) slow contraction (multiplying each particles' position by (1-epsilon)) is a technique used by generative digital artists to ensure that visual activity does not stray too far from a directed point.
The unique component of this simulation is the (computationally-efficient) dependence of a very small number (N=2 here) of neighbor particles. The typical O(N^2) that limits real-time simulations to 10k-50k particles becomes O(N).
- palad1n
Brings me back to when there were boids applets.
- yehoshuapw
I find it fascinating how (in the new version) the further away clumps stay separate, until something small from the larger swarm reaches them, then they all merge back to it