laws

bismuthplayground

The engine with the lid off. Pick the substrate — a cubic lattice, any plane tiling stacked straight, staggered into a close packing or twisted, or the icosahedral quasicrystal itself — paint the initial condition, rewrite the laws of the mason brain, breed or thin the colony. Every state here is a permalink — share copies it. Edits mid-growth apply live; reset replays the whole thing from scratch, which is what the link reproduces.

substrate the geometry the masons build on, and how many grains of it

grains1

misorientation30°

mixed tilings

radius30

stacking

stagger1

twist0°

Straight, a tiling stacks into prisms: one bond down, one up. AB hexagons are hexagonal close packing; ABC hexagons the rhombohedral family (bismuth's own lattice is one); the AB square grid is face-centred cubic. A twist turns every layer a little, so the bonds are wherever the tiles happen to overlap. Twelve bonds a brick where the courses line up, and the crystal facets in the new lattice's habit. Icosahedral is the real three-dimensional quasicrystal: golden rhombohedra, no lattice at all, and the painted columns become its nucleus. Grains make a polycrystal: the tiling turned by a different angle for each grain and set down at a different place, all sharing the layers, so where two grains' tiles overlap only one can hold a brick. Each grain grows from its own nucleus disk (the painted footprint is not used), the melt strikes every grain in proportion to the surface it shows, and where they meet is a grain boundary — the tiles that would straddle it stay empty, and a foreign wall shelters the terrace rule the way an own wall does. Mixed gives every grain its own tiling.

initial condition paint heights; the crystal grows on what you draw

brush2

grid24

left-drag paints columns of brush bricks; right-drag or brush 0 erases. Heights are the initial condition: plates, bars, rings, pillars, walls.

brain the laws every mason obeys

Kossel rates: the chance per visit of laying a brick that would touch 1, 2, or 3+ faces.

k1 · terrace

k2 · ledge

k3 · kink

rim

anisotropy — growth-rate weight per face normal.

−x

−y

+z · up

the walk and the melt.

patience

mobility

flight

arrive from above

sky pull

bond pull

the two nucleation gates.

patch min

patch full

patch part

lip along

lip depth ^

cool-down

the melt is above (nothing laid under a brick) lateral nucleation only at a top lip

or specimen №

packs reseed from this plane · demolish

The platformer primitives. Reseed: click a brick and a pack lands on the plane above it with the brain and colony above — its own budget, its own dice — and everything that was growing freezes: the old crystal is terrain now, the chosen plane is the new floor, and the pack builds only on and above it. Demolish takes bricks away with a click; masons standing on them fall back into the melt. Both are live edits: the link replays the base crystal, not your interventions.

plate3

worms ghosts of the masonry

A second wave, released into the crystal: worms tunnel from brick to brick along the bonds the masons made, never turning straight back, and now and then the brick they leave goes with them. A small effect by design — a wave of three eats an order of magnitude slower than a colony lays. With recycle on, every bitten brick returns to the melt as one more brick of budget for the colony still growing, so the system eats its own tail: not perpetual (a colony past its cool-down is past feeding), but a steady state of laying and erosion while it lives. Deterministic: same seed, same worms.

worms

speed

bite

length

recycle: a bitten brick feeds the live colony

The worm brain. depth is where it likes to be: −1 grazes the skin (bricks with one bond), +1 mines (bricks buried six deep), 0 wanders. reverse is how often it may turn back along its own trail. spawn after and starve make it a predator: a worm that has eaten that many bricks splits, and one that goes that many moves without a bite fades — set both and the population is a variable, not a dial. exposed makes only bricks with that few bonds edible: a grazer that cannot eat the interior, whose intake is bounded by the crystal’s surface. lost after is how long a ghost drifts in open void before sinking into the masonry elsewhere.

depth

reverse

spawn after

starve

exposed ≤

lost after

magnetism the crystal as a magnet: the flux lines of the whole

applied field

view

section

section offset

strength

field azimuth

field elevation

lines

Every brick is a dipole and the crystal's field is the applied field plus all of them; the lines are streamlines through that field, stopped where they meet a brick. Diamagnet is what bismuth actually is — the strongest diamagnet among the metals, a slab of it floats a magnet — exaggerated here by four orders of magnitude, so the crystal expels the flux and the lines crowd into its hollow. Paramagnet draws it in. Ferromagnet gives every colony its own domain, magnetized along an easy axis of the substrate that its growth anisotropy favours, so a crystal with deployed packs is a magnet of several domains and the lines read them out. First order: the dipoles do not feel each other. The field is retraced a few seconds apart while the crystal grows. Switch the applied field off and a ferromagnet keeps its magnetization — remanence — so what is drawn is the crystal's own field, seeded where it leaves the surface; the field view cuts the crystal on a plane and paints the field's strength on it, cold to warm on a log scale, with its direction as grain and the cut in the domains' colours.

colony population control

masons

birth every

retire after

min

max

oxide the interference palette

base nm

ramp nm

grain nm

warp

wavelength

run budget and pace

budget

seed

pace240

turbo (as fast as the frame allows)

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