Physarum Slime Mold

Jun 6, 2026

A model of Physarum polycephalum — the single-celled organism that solves mazes and independently rediscovered the Tokyo rail network. Each agent sniffs trail in three directions and turns toward the strongest signal. The collective deposits, diffuses, and decays a shared chemical map, building vein networks with no central plan.

AGENTS3000

SENSOR °0.4

SENSOR D9

DECAY0.015

Networks emerge over ~10s. SENSOR ° controls spread; higher DECAY thins the veins.

/ NOTES

HOW IT WORKS

Each agent has a heading and three forward sensors (left, centre, right). Every step it reads the trail concentration at each sensor, rotates toward the strongest, moves forward, and deposits a fixed trail amount. The map is box-blurred (diffusion) and multiplied by a decay factor each frame.

PARAMETERS

Sensor AngleWider angles spread the network; narrow angles create thin highways.

Sensor DistLonger reach makes agents anticipate paths further ahead.

DecayFaster decay forces frequent re-use of paths or the trail disappears.

Turn SpeedHow sharply agents can change direction each step.

WHAT TO TRY

Start with default settings and watch the diffuse fog condense into distinct veins over 10–15 seconds. Increase decay to see the network thin and collapse. Try a very wide sensor angle for a foam-like cell structure.

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