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Bird Flock

A flock of birds steered by Perlin-noise wind and boids rules. Flight speed, cohesion, alignment, and personal spacing all change automatically with Japan Standard Time — roosting at night, formation flight in the morning, murmuration at dusk.

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Bird Flock

A flock simulated with classic boids rules — separation, alignment, and cohesion — overlaid with a Perlin-noise wind field that continuously steers the birds in flowing, organic directions.

All three core boids parameters and the wind-noise speed are driven by the current Japan Standard Time (JST, UTC+9), shown in the bottom-left corner of the canvas. The current behaviour is labelled in the bottom-right corner.

Time (JST)PhaseWhat changes
00:00–05:00Night · RoostingVery slow, tiny separation, strong auto-cohesion — birds huddle in a near-stationary cluster
05:00–07:00Dawn · WakingSpeed and spacing gradually increase as the flock disperses from the roost
07:00–10:00Morning · FormationFastest flight, widest spacing, high alignment — birds lock into loose V-formation patterns
10:00–16:00Daytime · SoaringModerate pace, relaxed cohesion, birds spread freely across the canvas
16:00–18:00Evening · GatheringCohesion rises and spacing tightens as birds pull together before dusk
18:00–20:00Dusk · MurmurationStrong alignment + tight spacing → coordinated swirling mass; wind noise slows to calm gusts
20:00–24:00Night · RoostingRapid slowdown back to dense nocturnal cluster
ParameterEffect
Flock SizeTotal number of birds
Wind StrengthPerlin-noise wind influence — adds turbulence to each bird’s heading
CohesionExtra pull toward the flock centre, stacked on top of the automatic time-based value
Bird SizeWing-span of the chevron silhouettes

Click Scatter to randomly reposition all birds and restart from scratch.