How it works: Alan Turing (1952) showed two diffusing chemicals — an activator (V, fast reacting) and an inhibitor (U, fast diffusing) — could spontaneously self-organise into stable spatial patterns. The Gray-Scott model uses U (substrate) and V (product): V autocatalyses its own production (UV² term), while U is replenished at feed rate F and V decays at kill rate k. Different (F,k) combinations produce spots, stripes, labyrinths and coral-like structures.

Click on the canvas to inject a square seed of V. Explore the (F,k) parameter space — tiny differences lead to completely different pattern types.