A fold may appear without a hand drawing it. In this experiment we supply a beginning and a set of rules, then let the computation continue.
Your first observation
Watch Coral for a while. Then press Add a mark. See what the new spot does to the shapes around it. Reset reloads the same starting state for that world.
The three worlds use different settings of the same model. Switching worlds changes the feed, decay and starting arrangement as well as the colour. Their differences cannot be attributed to a single parameter.
Try changing just one thing
Reset Coral. Open Rules of this world and increase the feed a little. Watch for a while, then reset and try decreasing it. Does the pattern become denser, spread out or disappear?
There is no answer to score. The outcome depends on the value, the current state and how long you wait. Resetting gives two observations a common starting point.
Beneath the surface
The grid stores two numerical concentrations, A and B. A Gray–Scott reaction–diffusion rule updates each point alongside its neighbours. A is added, B is removed, and the reaction consumes A to produce B. Colours are computed from B’s concentration.
This implementation uses 240 × 160 points with opposite edges connected. Presets open from states already evolved for 1,600 steps; the counter records subsequent steps. It does not measure physical seconds or biological time.
What remains of this world?
Your marks stay in memory during this visit. This is not a persistent world shared with other visitors. To keep a moment, use the PNG button to save its image.
Coral and Islands are metaphors for what we see. For a closer look at what a model represents, read the field note.