readme.md

drift

A flow field. A few thousand particles, each asking the same question every frame: which way is the wind blowing here?

what you're looking at

There is no drawing of curves anywhere in the code. Every particle only ever draws a tiny straight line, one or two pixels long. The curves appear because neighbouring particles get nearly the same direction, so their trails bundle into strands.

The canvas is never cleared. A nearly transparent black wash goes over it each frame, which is what turns moving dots into fading trails.

things worth stealing from the prompt

"Never clear the canvas" is the single most important sentence. Remove it and you get a screen of dots.
"One particle in twenty is bright lime" gives the eye something to follow. All-white reads as texture; a rare accent reads as motion.
"Wind made visible, or hair, or iron filings" tells the agent what to tune towards when it has to pick numbers.

try changing

the fade strength (slower fade = denser, more painterly)
the number of wave layers in the field (more layers = more turbulence)
the lifetime (short lives give stubble, long lives give rivers)

Make a single self-contained HTML file: a full-window canvas artwork called "drift". No libraries, no text on screen, no controls. Thousands of tiny particles move across a black background, each one following an invisible field of directions. Build the field from three layered sine and cosine waves of the particle's position, and let it shift very slowly over time so the currents never repeat. Each particle draws a one-pixel line from where it was to where it is now. Most lines are faint white, about 20% opacity. Roughly one particle in twenty is bright lime (#b8ff2c) instead. Never clear the canvas. Each frame, paint a nearly transparent black rectangle over everything so old trails fade out over a few seconds. The result should look like wind made visible, or hair, or iron filings. A particle lives for a random 1 to 4 seconds, then respawns at a random position. It also respawns when it leaves the canvas. Scale the particle count with the canvas area, capped so it stays smooth on a laptop. Handle window resize and high-density screens.