Capability catalogue

Each capability lives in its own package, so a game loads only what it registers. The name is what host.enable(name), a manifest's physics.capabilities and the physics.* commands use.

Bodies#

Package	Name	Phase	What it adds
`physics-gravity`	`gravity`	field	gravity as a field: a uniform vector per scope, point attractors (a planet, a pit) with softening and range, a scale per body. The character reads it too
`physics-media`	`media`	field	water, mud, wind and air as media with density and viscosity: drag (linear then quadratic), buoyancy against the true volume below the surface, flow, gusts; the standard atmosphere
`physics-friction`	`friction`	strength	friction by scope on top of the materials' own: sliding and rolling, pivot friction, anisotropy. Ice is a material, not a special case
`physics-impact`	`impact`	strength	restitution from sticking to perfectly elastic, a rest threshold, energy lost reported as an event
`physics-strength`	`strength`	strength	finite strength: impacts damage and break bodies into pieces (capped by the tier's `maxPieces`); links that break over force or torque
`physics-stretch`	`stretch`	stretch	springs, ropes and bands (Hooke, damping, rest length, tear at maximum stretch); cloth and soft bodies by position-based dynamics

The ground, blasts, heat and matter#

Package	Name	What it adds
`physics-terrain`	`terrain`	a layered soil height field that can be dug, filled, slumps to its angle of repose and floods; sinkage of loaded bodies; tunnels; terrain as meshes for the kernel
`physics-explosions`	`explosion`	a blast from an energy: overpressure and impulse by scaled distance, shielding, fragments and spall, craters
`physics-heat`	`heat`	temperature of parts, heat capacity, conduction, convection, radiation, phase change, expansion, melting and loss of strength
`physics-chemistry`	`chemistry`	reactions with rate laws (Arrhenius) in well-stirred vessels, heat of reaction, pressure, venting
`physics-nuclear`	`nuclear`	decay and chains, activation, radiation dose and shielding along a ray, reactor kinetics with rods and scram, fallout
`physics-combustion`	`combustion`	combustion chambers, guns, rockets, piston engines, steam boilers, jets: burning raises temperature and pressure, flow through nozzles

Machines and vehicles#

Package	Name	What it adds
`physics-electric`	`electric`	circuits of sources, wires, resistors, lamps, motors, inductors, capacitors, relays and potentiometers, solved each step
`physics-mechanisms`	`machine`	drivetrains of shafts and couplings, gears, belts, clutches, brakes, turbines, cardan joints, tooth strength
`physics-vehicles`	`vehicles`	ships, submarines, balloons: hulls, ballast, flooding, thrusters, foils and sails
`physics-liquids`	`liquids`, `surface`, `fluid`	three models of growing cost: containers and reservoirs (pressure by depth, communicating vessels), a height-field water surface (waves, currents, boats that push it), particles (splashes, viscosity, surface tension, capillarity)

Glue and look#

Package	Name	What it adds
`physics-links`	`links`	closes loops between capabilities, see Linking capabilities
`physics-fx`	none	the render side: glow of hot parts (blackbody colour), water meshes, fluid views, lamp lights. It reads state and never changes it
`physics-havok`	none	the loader for Havok's WASM

Dependencies are data#

Strength and stretch use a material's strengths; friction and impact use its friction and restitution; media uses a body's density and extent; liquids use a liquid's density, viscosity, surface tension and contact angle; gravity uses nothing. A capability that needs another declares it in requires.

Every API item of a capability is on its package page; every capability also registers commands (gravity.set, heat.add, circuit.add, terrain.dig, ...), listed in Commands.

The packages of the dynamics plan as libraries (stage M)#

npm run libs (tools/code-lib/build.mjs) packs motion, flow, physics-actuators, physics-rotor, physics-engines, flow-solver and physics-pneumatics as .ferret libraries (dist/lib/ferret-libs/<id>-<version>.ferret). A library is the package's src/library.ts as one ES module: its own code, with the rest of the engine read from the shared Ferret (ctx.ferret), and install(ctx) registers its capability or service (actuators, rotors, flowbox, pneumatics, the flow service). The manifest lists dependencies (the code loader runs them first) and provides (capabilities, kinds, flow sources, forms, commands, level keys) so a level or a program is resolved to libraries without running them. Libraries are built unsigned; signing is done with the owner's key at release.