How it listens
Particles wander at random until they touch the aggregate and settle. Each one that settles is a candidate for a note.
- Pitch
- how far from the seed it settled; deeper inside is lower
- Stereo
- where it sits on your screen, left to right; in three dimensions the music turns as you orbit
- Depth
- in three dimensions, how far it is from the camera; distant particles sound farther away, with more reverb
- Voice
- how it touched the cluster: at a point it is a tip and rings as a bell, along a face or ridge it plucks, wedged in two places at once it blooms into a chord
- Drone
- opens as tips dominate, darkens as crevices take over
The two dimension buttons switch between a flat aggregate drawn on a canvas and a solid one you can orbit. The physics is the same in both: a lattice random walk with four neighbours in the plane and six in space, with contact judged over the whole rim or shell of the arriving particle.
Particle size is the diameter of each arriving particle in lattice cells. Larger particles thicken every branch and coarsen the structure; because contact is judged over the particle's whole rim, a big particle at a tip still rings as a bell and one wedged in a crevice still blooms into a chord. Change it mid-growth and the new layer grows at the new scale.
The sticking coefficient is the chance a particle stays the first time it touches. At 1, everything sticks on contact: thin dendrites race outward, tips dominate, and you hear sparse bells high in the register over an open drone. Lower it and particles slip along the surface and deep into the fjords before settling: the aggregate thickens, crevices multiply, and the music sinks into chords and lower notes while the drone closes. Change it mid-growth to hear the new outer layer take on a different texture.
The fractal dimension in the readout comes from watching the cluster grow: its mass is plotted against its radius of gyration over the whole run and the slope of that log–log line is the dimension. Measuring the scaling across sizes, rather than inside one snapshot, avoids the thinned-out outer zone that makes a single snapshot read low. Classic aggregation gives about 1.7 in the plane and 2.4 to 2.5 in space; compact, mossy growth climbs toward 2 and 3. The ring, line, sphere and plane seeds grow from a substrate rather than a point, so they get a box-counting estimate instead, which on a cluster of this size reads a little below the true value. The model, the mapping, and the estimators are described in full in the technical note (PDF).