Aquarium Fish Schooling (2D)

School Parameters

Fish count 28

Separation weight 1.4

Alignment weight 1.0

Cohesion weight 0.8

Swim speed 1.0×

Click anywhere in the tank to drop food — nearby fish break formation and chase it, then regroup into a school.

Live Statistics

Fish fed

School cohesion

–

Avg neighbor dist

–

Food active

How it works

Each fish is an independent agent that blends three classic Reynolds boid rules every frame: separation steers away from fish that are too close, alignment matches heading with nearby schoolmates, and cohesion steers gently toward the local group's center. The three weighted forces are summed with a wall-avoidance term (soft steering, not a hard clamp) and a mild random wander so the school never freezes.

Dropped food adds a strong, short-range attraction force that only fires for fish within sensing range of it — this is why nearby fish peel off the school while distant ones keep schooling normally, and why the group re-forms once the food is eaten.

Separation — raise it to keep fish more spread out; at 0 they overlap freely.
Alignment — raise it for a tight, uniform-heading school; at 0 fish ignore each other's direction.
Cohesion — raise it to pull loners back into the group; at 0 the school can drift apart.
Cohesion stat — the school's radius of gyration (smaller = tighter school); avg neighbor dist is the mean distance to each fish's 3 nearest neighbors.

Schooling fish Food Bubbles