flow fields, explained

a flow field gives every point in a space a direction, like invisible currents. release particles into it, let each one follow the current beneath it, and they trace flowing, organic lines. the demo below is live. click to stir in a gust.

what's actually happening

under the surface is a grid of directions, one arrow at every point, usually drawn from a noise function so neighbours point almost the same way. each particle looks at the arrow beneath it, takes a small step that way, and repeats. thousands of these little journeys, layered up, become the flowing image.

where you'll see them

flow fields are one of the most loved techniques in creative coding and generative art. the same idea turns up in wind and water simulations, hair and fur, and the swirling, smoke-like pieces you'll find all over generative-art galleries. they usually ride on noise.

how gaogao uses flow

gaogao has a flow gene: when it expresses, it bends an organism's marks along a current rather than leaving them straight, which is where a lot of gaogao's sense of movement comes from. the demo above is that idea in its purest form.