Physarum trails guide
Every control
Every control in the panel, top to bottom. The picture itself is a control too: tap it to scatter the agents round that point.
Load and save
Under the tiles a line says what plays: the samples until you add your own, then A plays into B. Kept on this device, never uploaded. Your pictures follow you to every lab tool that takes a picture, until you press × on a tile.
- Image AButton
- Picture A as a tile: press it to add or replace your own; two pictures picked or dropped at once fill A and B. The × on a picture takes it away and the sample plays again. Your pictures stay on this device and follow you to every lab tool that takes a picture.
- SwapButton
- Exchanges A and B, so the transition plays the other way. With one picture of your own, it moves to the other side and the sample takes its place.
- Image BButton
- Picture B, the one A plays into, as a tile: press it to add or replace your own. The × takes it away and the sample returns. See PNG and JPEG.
- Save PNGButton
- Saves the frame as it is at that moment, as aikizi-physarum-trails.png. See PNG.
- Record videoButton
- Records one run: it presses Replay itself and records the canvas for up to seven seconds. While recording it reads Stop recording; press it to stop early. See record video.
- ReplayButton
- Clears the trail, scatters every agent evenly over the picture and grows the network again. With the same pictures and settings, each run grows the same network. See replay and pseudo-random.
Effect
- EffectChoice
- Opens another of the 14 image transitions. Each one is its own page, so your pictures and settings stay behind.
Presets
- Capillaries · Gold veins · Crimson web · Mycelium · StarvedPick one
- Sets every control at once, with A → B transition on. It does not start a run, but a preset with a different number of agents starts a fresh colony. The highlight goes as soon as you move a control. On a phone or touch screen a preset keeps Agents at 256 · 65k.
- Capillaries: The opening look: fine, dense gold threads that hug the bright parts of the picture. 65k agents, sensor angle 0.5, reach 6, food pull 2.2, trail decay 0.9, 2.4 seconds. See capillaries.
- Gold veins: Thick gold trunks: wide, far-reaching sensors, slow turns, long-lived trail and heavy spreading. 262k agents, reach 15, trail decay 0.965, diffuse 0.6, portrait dim 0.7, 2.8 seconds.
- Crimson web: A tight red lattice: narrow sensors, fast turns and a strong deposit. 262k agents, sensor angle 0.28, turn speed 0.62, deposit 0.13, food pull 0.9, 2.2 seconds.
- Mycelium: A sprawling ivory mesh: the widest and longest sensors, lazy turns, fast agents and the most spreading. 147k agents, sensor angle 0.95, reach 18, move speed 1.6, diffuse 0.75, 3 seconds. See mycelium.
- Starved: Sparse slate threads that keep searching: weak food pull and a trail that fades fast. 65k agents, food pull 0.35, trail decay 0.86, 2 seconds, ease out. See starved.
Sliders
Every control here, the switch and lists included, changes the colony at once, even mid-run.
- AgentsChoice
- How many agents there are: 256 · 65k, 384 · 147k or 512 · 262k. The first number is the side of the square texture that holds them. More agents draw finer, fuller networks and ask more of the graphics card. Changing it starts a fresh colony. On a phone or touch screen the page opens at 256 · 65k and presets and Reset keep it there; picking more by hand still works. See agent count.
- TintChoice
- The colour of the threads: Gold, Crimson, Slate or Ivory. They are laid over the picture so that they only ever lighten it.
- A → B transitionOn or off · starts on
- On, a run fades the picture from A to B and moves the food from A's bright parts to B's, so the network follows. After the run B stays; Replay starts again from A. Off, only picture A is used. It starts on, and every preset and Reset keep it on. See crossfade.
- Transition speedSlider · 0.3 to 4 · starts at 1.9
- How fast a run plays; right is faster. A run lasts 4 seconds at the left end and 0.3 seconds at the right, always 220 steps. The number beside it compares with the opening 2.4 seconds, so it reads 1.00× at the start. After a run the colony moves one step a frame whatever this says.
- Sensor angleSlider · 0.1 to 1.3 · starts at 0.5
- How far to the left and right of straight ahead each agent looks, from about 6 to 75 degrees. Narrow angles make tight, fine webs; wide ones make broad loops. See sensor angle.
- Sensor reachSlider · 2 to 22 · starts at 6
- How far ahead each agent looks, in cells of the trail map, which is 512 cells along the picture's long side. Longer reach joins distant paths into longer, straighter trunks. See sensor reach.
- Turn speedSlider · 0.05 to 1 · starts at 0.32
- How far an agent turns in one step towards the strongest trail, from about 3 to 57 degrees. See turn speed.
- Move speedSlider · 0.2 to 2.4 · starts at 0.8
- How many cells each agent moves in one step. Faster agents cover the picture sooner and draw longer strokes. See move speed.
- Food pullSlider · 0 to 3 · starts at 2.2
- How strongly the bright parts of the picture pull the agents, against the pull of the trail. At 0 they ignore the picture and follow only each other. See food pull.
- DepositSlider · 0.02 to 0.4 · starts at 0.045
- How much trail each agent adds on each step. More deposit makes brighter, bolder threads. See deposit.
- Trail decaySlider · 0.8 to 0.99 · starts at 0.9
- How much trail is kept from one step to the next: at 0.99 almost all of it, so paths last; at 0.8 it fades fast, so only busy paths show.
- DiffuseSlider · 0 to 1 · starts at 0.22
- How much the trail spreads into its neighbours each step. At 0 it stays where it was laid; at 1 each cell becomes the average of the nine around it, so threads soften and thicken. See trail diffusion.
- Filament floorSlider · 0 to 0.5 · starts at 0.22
- How much trail a spot needs before it starts to glow. Raise it to hide faint paths and keep only the busy ones. See threshold and smoothstep.
- Filament peakSlider · 0.2 to 0.95 · starts at 0.75
- How much trail a spot needs to glow at full strength; the densest cores glow brighter still. Lower it for more bright threads. If it is set below Filament floor, the threads glow as if it sat just above the floor. See filament.
- Portrait dimSlider · 0 to 1 · starts at 0.42
- How much the picture under the threads is darkened. At 0 it shows at full brightness; at 1 it drops to about a fifth, never to black. See portrait dim.
Export
Under the buttons, a line tells you what the last export did, such as PNG saved.
Reset
Back to the Capillaries preset. Your pictures stay.
- ResetButton
- Sets every control back to the Capillaries preset, with A → B transition on. Your pictures stay. The colony carries on from where it is, unless the number of agents changes, which starts a fresh one.