Hyperparameters

Hyperparameters

Defaults as the engine ships them. Everything is live-editable in the Hyperparameters tab, and the labels there describe what a setting does to the world rather than what variable it writes.

Ecology

Setting	Default	What it does
lifespanMultiplier	100	Lifespan is cell count times this
foodProdProb	5	Chance per tick that a producer cell drops food in an adjacent empty cell
sightedProducerRate	0	A sighted body produces food at this fraction of a blind one's rate. At 0, having an eye switches photosynthesis off entirely, so thinkers must hunt
foodDropProb	0	Free food appearing from nowhere. Off: the food chain runs through producers
sightedFoodCost	0	Extra food a sighted organism must collect before reproducing
foodBlocksReproduction	true	Food cells block a birth
instaKill	false	One touch from a killer cell is fatal
maxOrganisms	−1	Population cap; −1 is uncapped

The first three are the ones that decide whether a world is hospitable. Sight costs food production and buys movement; at sightedProducerRate = 0 that trade is absolute, and a sighted lineage either learns to graze on producer colonies or dies.

Mutation

Setting	Default	What it does
useGlobalMutability	false	Use one fixed rate for everyone instead of inherited rates
globalMutability	15	That fixed rate, in percent
addProb / changeProb / removeProb	33 / 33 / 33	Relative weights for growing, changing and losing a cell
rotationEnabled	true	Bodies may rotate. Off: orientation is fixed for life and the turn actions always fail

With useGlobalMutability off — the default — every organism carries its own mutability, starting at 15% for founders and drifting ±1 on each birth with a floor of 1. Lineages evolve how fast they evolve.

Perception

Setting	Default	What it does
lookRange	20	How far an eye sees, in grid cells
seeThroughSelf	true	Eyes see past their own body. Off: an own-body cell reads as a mild obstacle, so body geometry comes under selection

Brain

Setting	Default	What it does
brainN	16	State vector length. Range 4–64
brainSharedFrac	0.5	Fraction of state shared through the field. Range 0–0.9
brainInitScale	0.6	Spread of initial random weights
brainMutationSigma	0.08	Standard deviation of per-weight mutation
brainActionThreshold	0.15	Below this the top logit is ignored and the creature holds course

brainActionThreshold is worth knowing about if populations die too readily: below it a creature holds its heading, which against a wall means continuing to press into it. Lowering it lets the escape actions win more easily.

Collective field

Setting	Default	What it does
collectiveTileSize	6	Storage resolution, grid cells per tile
collectiveRadius	20	Influence disc radius in grid cells
collectiveLeak	0.85	Field memory; higher means slower-moving culture

World start

Setting	Default	What it does
randomStart	false	Seed the world with a diverse random crowd instead of one ancestor
maxStartPopulation	20000	Cap on founders when the crowd is used

Off, a world begins as the classic single static ancestor — mouth plus two producers — and has to evolve movement and sight for itself. On, it begins with roughly one founder per 100 grid cells, some of them already sighted and thinking, so regional cultures form immediately.