Metaballs Screensaver
The Metaballs screensaver extracts an isosurface from a scalar field: six moving sources each contribute a field that falls off with distance, and the surface is wherever the total crosses a threshold. It runs in the browser with nothing to install; press ESC to exit.
How the Metaballs 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 loads only when a 3D screensaver actually runs.
It reads nothing external — the field and its surface are computed in the browser each frame.
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
The field is sampled on a 26-cube grid every frame, then the surface is found by checking each grid edge for a sign change and emitting geometry there. That is why two blobs merge into a smooth neck rather than intersecting as two spheres would: there is no sphere anywhere in the calculation. What you see is the boundary of a region, and regions merge.
Settings & tips
- Accent and Background recolour the scene; Speed changes the pace of the motion and the camera.
- Add it to a Multi-view grid, though 3D savers are heavier than 2D ones and a few per screen is plenty.
- Press ESC at any time to leave fullscreen.
Frequently asked questions
- What is an isosurface?
- The set of all points where some quantity has a particular value — like a contour line on a map, but in three dimensions. Medical scanners and terrain software use exactly the same idea to turn a volume of measurements into a surface.
- Why does it look faceted?
- Because the surface is extracted on a grid, and a finer grid costs more per frame. Flat shading is used deliberately so the facets read as an aesthetic rather than as an error.
- 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.