From a wish to the right capabilities

Skill ferret-physics-recipes · download all skills · SKILL.md

When to use#

You know what should happen in the game, not which package does it.

Wish to capability#

Steps#

1. Find the closest recipe in recipes/ (cookbook pages by theme, scenarios for whole chains).
2. Read the capability skill named above for the switch-on steps and the failure table.
3. Register and enable only what the level needs (ferret-physics-host); set values at the narrowest scope.
4. Copy the numbers into a test in the fixed-step world; assert against a law, not against a value seen once.
5. Measure the step time and set the tier (ferret-physics-fx-tuning).

Check afterwards#

The recipe's expected outcome appears in a headless run; the energy or mass balance closes where the guide says it should.

What usually goes wrong#

• A capability used without being enabled (physics.info shows what is on).
• Reaching for one package when the effect is a chain: use links, not special code.
• Large numbers copied from a recipe into a different unit system: everything is metres, kilograms, seconds, kelvin.

Files#

• reference/overview.md — Realism as capabilities a game switches on, the host and kernels, scoped values, the fixed phases, budgets and tiers.
• reference/capabilities.md — Every physics capability: the package, its registered name, its phase and what it adds.
• recipes/fire-and-heat.md — Eight recipes: boil a pot, a beam in a fire, a pressure cooker, a kettle on a breaker, a cold pack, thermal runaway, an overloaded wire, a glowing brake disc.
• recipes/structures-and-ropes.md — Six recipes: a rope that holds a load or snaps, a shear pin that protects the rest, a crate that breaks only at speed, a bungee that springs back, a wall that breaks under a blast, a curtain that hangs.
• recipes/water-and-boats.md — Six recipes: tanks that equalise, a U-tube of two liquids, a wave that slows on a beach, a boat that sinks deeper with cargo, a wing that stalls, a ball that curves.
• recipes/blasts-and-ground.md — Seven recipes: danger rings, a crater in sand and in rock, a charge buried too deep, a crater in a real terrain, a wall that shields, an underwater burst, a trench that holds or slumps.
• recipes/machines-and-circuits.md — Six recipes: a lamp that surges and burns, a rectifier that smooths, a transformer, a wind turbine lighting a lamp through a generator, a winch that cannot run back, a flywheel that evens out a pulsing drive.
• recipes/reactions-and-radiation.md — Six recipes: how much lead, a hot patch that fades and washes, a reactor without cooling, equilibrium shifted by squeezing, a rocket that gains with altitude, a barrel that bursts.
• recipes/boiler-house.md — A fire heats a boiler, steam drives an engine, a generator on the shaft lights a lamp. Four capabilities, three links, one energy account that must add up.
• recipes/flooded-cellar.md — A burst main fills a cellar faster than the sump pump can empty it; the water reaches a socket, the circuit shorts, the breaker trips, the pump stops, and the flood wins.
• recipes/loss-of-coolant.md — A reactor runs a turbine, a generator and a lamp. The coolant pump stops; the lamp dies, the trip scrams the core, and decay heat warms the containment.
• recipes/progressive-collapse.md — Two parallel hangers share a load. When the weaker one goes the stronger one inherits all of it and fails too: progressive collapse, with redundancy as the cure.
• recipes/tank-fire.md — A fire heats a sealed tank, the gas inside warms and its pressure climbs, the shell gives way and the tank becomes a blast with fragments that push a crate. Heat, links, gas, explosions and bodies in one loop.
• recipes/tuning.md — Where the cost of the capabilities goes and which knob buys it back: sub-steps, step rates, off-screen sleep, and what to switch off first.