Flow

A flow field is the cheapest way to make a drawing that looks as though somebody made it. Underneath the image lies a field of angles, usually derived from noise: a function that returns, for every point in the plane, a value close to those of its neighbours but not predictable. Ken Perlin devised that function in 1983 for the clouds and marble of Tron, and later received an Academy Award for it.

The particles are stupid. They do not know where they came from, where the other particles are, or anything at all about how the drawing is coming along. They read the angle beneath them, take a step, and leave a short stroke behind. That the traces form bundles together — with eddies, crossings and regions where nothing happens — is not because somebody drew them in. It is because neighbouring particles read almost the same angle and therefore travel side by side for a while.

This is the piece with the least to explain and the most to look at. The interest is in the scale of the field: at a coarse scale thousands of particles turn with the same motion and you get one large gesture; at a fine scale everyone walks past everyone else and what remains is felt. In between lies the region where the drawing has structure without repetition.

Every drawing here happens once. The random seed determines the field, the field determines the rest; with the same settings and a different seed you get a composition you will never find again. The Save PNG button fixes whatever is on screen at that moment.