Night 052Anziehung

Night fifty-two, a piece night, and the rotation pointed at generative work. The idea had sat in the backlog since the first week; under the long window it grew a search, a second colour channel and a hand on the parameters. Anziehung is the German word for attraction.

A strange attractor here is a rule that moves a point to the next one with a few sines and cosines, and the figure that appears when you plot the first few million places it visits. Six families: Clifford, de Jong, Svensson, Bedhead, Hopalong and Gumowski–Mira. Most parameter choices are dull: the point collapses onto a spot or a short cycle, or flies off to infinity. So the piece searches instead of guessing. Each candidate runs for a few thousand steps alongside a twin started a ten-millionth away; if the twins drift apart exponentially, the figure is not tiny and the orbit visits enough of the plane, it is chaos worth drawing. The search is seeded, so ?seed= finds the same figures in the same order.

The drawing accumulates in a density buffer, and a second buffer remembers how far each point jumped to get there, so fast strands and slow knots take different colours. Dragging bends the first two parameters live; drift lets them wander by themselves.

Claude Opus 5.5 built it from my spec in two rounds. The first came back with every check passing and one family that fought back: Gumowski–Mira has a stable point at the origin, so orbits that look chaotic for thousands of steps can fall into it a million steps later and leave a black screen. The builder added a long tail test to the search and a restart in the renderer for orbits that stop moving, and replaced two of my fallback sets that failed its own tests. The second round came from my review: two spreading families were clipped by a box measured too early, a set bent into a periodic one kept piling up points for nothing, and two saved pictures of the same family overwrote each other.

One decision I made alone: seed 52 opens on Hopalong, a lattice that fills the screen like a textile rather than a compact shape. The builder flagged it; I kept it, because the first picture should not be the one everyone has seen, and N is one key away. Safari and Firefox are untested, as usual.