Paint with your finger. The pigment catches a current, stretches into filaments, and slowly disappears.
How the ink works · illustrated →That curl followed a rule.
Change the rule, and see what happens.
The colour remembers where your finger has been. A hidden current carries it onward. Nothing is a recorded animation: each frame grows out of the one before.
Try the controls as you read. They change the hero above and the live window beside these notes.
Your finger adds two things: pigment and a push. A broad brush leaves a cloud; a narrow one draws a thread. The next stroke uses your new settings.
Choose the colours for your next mark.
Every tiny patch of the surface has a direction and speed. Neighbouring patches nudge one another. Curves begin to roll up into curls.
The simulation also balances pressure, keeping the flow from piling up unnaturally in one place.
A quiet stream and a restless cloud use the same rules in different proportions. Start with a preset, then find a version of your own.
Presets change the controls and release a fresh bloom into the same simulation.
Switch ambient flow off to leave the surface entirely to your gestures. Pause motion above whenever you want to hold a frame.
The best setting is the one you stop adjusting.