Murmuration Screensaver
The Murmuration screensaver flocks 420 birds in three dimensions using Craig Reynolds's three boid rules: separation, alignment and cohesion. There is no leader and no choreography. It runs in the browser with nothing to install; press ESC to exit.
How the Murmuration screensaver works
The saver renders with three.js on your GPU. The library is vendored into this site rather than fetched from a CDN, and is loaded only when a 3D screensaver actually runs.
It reads nothing external — the simulation runs in the browser and is drawn with instanced geometry.
The scene resizes with the window and releases its WebGL context when the saver stops, so shuffle mode and Multi-view can cycle 3D savers without exhausting the browser's context limit.
If WebGL is unavailable the saver says so on screen rather than showing an empty black box.
A worked example
Every bird looks at a sample of its neighbours and does three things: steer away from any that are too close, match the average heading, and drift toward the average position. Nothing else. The folding, splitting and re-forming of the flock is not programmed anywhere — it is what those three rules produce. All 420 are drawn as a single instanced mesh, because 420 separate objects would spend the whole frame issuing draw calls.
Settings & tips
- Accent and Background recolour the scene; Speed changes the pace of both the motion and the camera.
- Add it to a Multi-view grid, though 3D savers are heavier than the 2D ones and a few per screen is plenty.
- Press ESC at any time to leave fullscreen.
Frequently asked questions
- Who invented this?
- Craig Reynolds, in 1986. The model was immediately convincing enough to be used for film crowds, and it remains the standard demonstration that complex group behaviour needs no central plan.
- Why does it look different from a 2D swarm?
- Because a flock in a volume can fold through itself. Watching a real murmuration, the dark bands are places where the flock is deep along your line of sight, and that only happens in three dimensions.
- Does this need a special browser or plugin?
- No. It uses WebGL, which every current desktop and mobile browser supports. Nothing is installed and no plugin is required.
- Does it cost anything or need an account?
- No. Every screensaver here is free, runs in the browser and needs no sign-up.