Differential Growth
The curve is a chain of points connected by edges, like beads on a string. Every step,
each point feels a few simple rules:
stay connected
Each point is pulled toward its neighbors so edges hold a target length — the chain
doesn't fall apart or stretch into spaghetti.
personal space
Any two points that drift too close, even ones far apart along the chain, push each other
away. This is the key rule: the curve refuses to touch or crowd itself. If you draw more than
one curve, this rule applies between them too — separate curves push each other apart, but
each one only holds itself together, so they compete for the same limited space.
smoothing
Each point is nudged toward the average of its neighbors, relaxing sharp kinks into
gentler curves. Turn it down for jagged, fingerprint-like ridges; up for smoother,
coral-like folds.
growth
Whenever an edge gets stretched past a length limit, it splits in two. The curve is
constantly gaining new points and total length.
why it folds
The curve keeps growing longer, but it's stuck in a bounded dish and forbidden from
overlapping itself. The only way to pack ever more length into a fixed area without
self-touching is to buckle and wrinkle — nobody programs the folds, they're forced by
growing length + no self-overlap + bounded space. The same three rules produce the
convolutions of brain cortex, coral, kale leaves, intestines, and fingerprints.