Physarum — a living transit map

In 2010, Tero and colleagues set oat flakes out in the pattern of the cities around Tokyo, and the slime mold Physarum polycephalum grew a network close to the real rail system. The same year Jeff Jones published a model of the mold built from simple agents that sense and follow a shared chemical trail. This page runs that model on up to a million agents.

Pointer

Tap / click
Place a station
Drag a station
Reroute the network
Double-click / long-press
Remove a station
Right-drag / two fingers
Paint a lake (fades in ~8 s)
Shift-drag
Seed raw trail
Mobile mode
Station / Lake / Seed in the Tune sheet

Keys

1–5
Presets
Space
Pause / resume
R
Reseed (disc, ring, nodes, random)
C / N
Clear trails / clear stations
E
Evolve parameters
S
Species 1 → 2 → 3
V
Palette variant
B
Bloom on / off
P / U
Save poster / copy share link
M
Chime on / off
H
Hide / show UI
[ / ]
Agent density down / up
? / · Esc
Help · close
Tab
Focus stations on the map
←↑→↓
Move focused station (Shift: 5%)
Del · Enter
Remove focused · add at centre