Murmuration

Murmuration fills the sky around an object with a flock of starlings: thousands of small birds swirling as one body, folding into dark, dense sheets and opening out again. Waves of light and shade ripple through the flock as the birds bank together.

How it works

Each bird follows three simple rules: keep a little distance from its neighbours, match their heading and stay close to them. Like real starlings, a bird watches its seven nearest neighbours rather than every bird within a fixed distance, and that is what lets a turn started by a few birds spread through the whole flock as a wave. The flock circles a roost point that drifts on a slow, never-repeating path, so the shape keeps turning over. An unseen raptor cruises through the airspace; birds near it scatter, tearing the sheets apart before the flock closes again. Birds bank as they turn and catch the light from above, which is why the flock flickers brighter and darker as a wave passes.

Settings

• Count: from a hundred to four thousand birds.
• Flock Radius: the size of the airspace the flock uses.
• Cohesion: the pull together; high values give tight balls.
• Alignment: how strongly birds match heading; it drives the waves.
• Separation: the push apart; high values thin the flock out.
• Bird Size and Color.

Use it for

Dusk skylines, wildlife films, atmospheric backdrops. The Flock object effect breaks an object itself into birds.