Concept index

The routing table. Search a concept (the search icon or S), open the named files, start reading at the entry symbol. Paths are repo-relative; every row was verified against the tree. For API detail run cargo doc --open -p <crate> locally - every crate exposes a prelude. For prose depth, follow the chapter linked at each group heading.

Boot and frame flow

Depth: Architecture.

Concept	Crate(s)	Key files	Entry symbol	Orientation
App boot, app assembly, plugin order	`nova_core`	`crates/nova_core/src/lib.rs`	`AppBuilder`	`build()` wires the whole plugin stack; game binary + CLI flags in `src/main.rs`.
Game states, pause	`nova_gameplay`, `nova_menu`	`crates/nova_gameplay/src/lib.rs`, `crates/nova_menu/src/pause.rs`	`GameStates`, `PauseStates`	State enums + `GameMode` live in gameplay; ESC overlay, `toggle_pause` and the clock freeze in menu.
Frame flow: Update vs FixedUpdate	`nova_ship`, `nova_gameplay`	`crates/nova_ship/src/lib.rs`, `crates/nova_gameplay/src/plugin.rs`	`SpaceshipSystems`	`NovaShipPlugin` chains the set brackets identically in both schedules; avian physics runs in `FixedPostUpdate`. Which schedule your system goes in: the Architecture chapter.
Asset loading gate, mod merge	`nova_assets`	`crates/nova_assets/src/plugin.rs`, `crates/nova_assets/src/merge.rs`	`GameAssetsPlugin`	`GameAssetsStates` gates entry to the menu/game; `register_bundles` merges base + enabled mods into the `Game*` resources.

The ship

Depth: Ship sections internals.

Concept	Crate(s)	Key files	Entry symbol	Orientation
Ship building from sections	`nova_scenario`, `nova_ship`	`crates/nova_scenario/src/objects/spaceship.rs`, `crates/nova_ship/src/sections/base_section.rs`	`insert_spaceship_sections`	Observer on the ship root spawns one child per `SectionKind` config, resolving prototypes; `SpaceshipConfig` is the authored shape.
Section integrity: damage, disable, destroy	`nova_gameplay`	`crates/nova_gameplay/src/integrity/mod.rs`, `crates/nova_gameplay/src/damage.rs`	`NovaIntegrityPlugin`	`Health` store and the disable/destroy chain; typed `DamageType` + the travel rule (`apply_damage`, `pierce_remainder`). Health decides WHEN a body dies; the two readings below decide what it looks like.
How far gone a body looks	`nova_gameplay`	`crates/nova_gameplay/src/integrity/erosion.rs`	`DamageLevel`	One scalar, 0..1, derived from the entity’s OWN `Health`. Grades every whole-body effect.
Where a body was hit (marks, carve cost, merge)	`nova_gameplay`	`crates/nova_gameplay/src/integrity/carve.rs`	`DamageMarks`, `mark_radius`	Spheres in the body’s local frame, priced by what the hit ABSORBED at `DAMAGE_PER_UNIT_VOLUME` (8 hp per cubic unit); `record_blast_marks` cuts one crater per body.
Authored per-section damage looks	`nova_ship`	`crates/nova_ship/src/sections/damage_effects.rs`, `damage_cracks.rs`, `damage_sparks.rs`, `damage_plume.rs`	`DamageEffects`, `fit_damage_effects`	`Cracks`/`Sparks`/`Plume`, one component each, default `[Cracks]`. No ship section ever loses geometry.
Carve debris: dust and severed pieces	`nova_gameplay`	`crates/nova_gameplay/src/integrity/spew.rs`, `crates/nova_gameplay/src/integrity/chunk.rs`	`CarveSpew`, `ShardLook`, `spawn_carved_chunk`	Shards are keyed on the WEAPON CLASS - kinetic and pierce chip, explosive does not; only a cut that SEVERED material spawns a real body, floored at `CHUNK_MIN_VOLUME`.
Severing, wreck fragments, structural collapse	`nova_ship`	`crates/nova_ship/src/sections/integrity.rs`	`ShipIntegrityPlugin`	Builds the section graph, splits disconnected structure (`sever_disconnected_structures` -> `ShipWreckFragmentMarker`), runs `cascade_structural_collapse`.
Neutralization (combat-dead)	`nova_gameplay`	`crates/nova_gameplay/src/integrity/neutralize.rs`	`NeutralizedMarker`	An armed ship that loses all weapons, or the flight computer it had, fires `OnNeutralizedEvent`; the hull may survive.
Ship skins, styles, greebles	`nova_ship`	`crates/nova_ship/src/sections/shell_skin.rs`, `crates/nova_ship/src/sections/skin_style.rs`, `crates/nova_ship/src/sections/skin_decor.rs`	`ShipSkinPlugin`	Cladding derived from structure; styles resolve by id (`ShipStyleConfig`, `GameStyles`); deterministic greeble scatter (`scatter_decor`).
Turrets, aiming	`nova_ship`	`crates/nova_ship/src/sections/turret_section/mod.rs`, `crates/nova_ship/src/sections/turret_section/aim.rs`	`TurretSectionPlugin`	Authored joint tree; lead-intercept aim (`update_turret_aim_point`, `muzzle_on_target`); arcs and firing in sibling files.
Torpedoes, point defense	`nova_ship`	`crates/nova_ship/src/sections/torpedo_section/mod.rs`, `crates/nova_ship/src/input/point_defense/mod.rs`	`TorpedoSectionPlugin`, `SpaceshipPointDefensePlugin`	Bay + guided round lifecycle (`TorpedoGuidance`, `TorpedoBlast`); PD splits target assignment from mount authority (borrowed player mounts).
Flight autopilot verbs (STOP, GOTO, ORBIT), PD attitude controller	`nova_ship`	`crates/nova_ship/src/flight/state.rs`, `crates/nova_ship/src/sections/controller_section.rs`, `crates/nova_ship/src/physics/pd_controller.rs`	`FlightVerb`, `Autopilot`	Controller sections grant verbs; the flight layer flies them (`NovaFlightPlugin`); `PDControllerPlugin` is the attitude loop.
Radar locking, targeting	`nova_ship`	`crates/nova_ship/src/input/targeting/mod.rs`, `crates/nova_ship/src/input/targeting/state.rs`	`SpaceshipTargetingPlugin`	Radar search writes the two sticky lock slots on the ship root: `TravelLock`, `CombatLock`.
Gravity wells	`nova_gameplay`	`crates/nova_gameplay/src/gravity.rs`	`GravityWell`	Inverse-square wells with an SOI cutoff; anchors and asteroids publish one.

Scenario and modding

Depth: Scenario engine.

Concept	Crate(s)	Key files	Entry symbol	Orientation
Scenario engine, mission scripting	`nova_scenario`, `nova_events`	`crates/nova_scenario/src/lib.rs`, `crates/nova_events/src/engine.rs`	`NovaScenarioPlugin`	A scenario is handlers = event + filters + actions over `NovaEventWorld`; the generic queue/dispatch (`EventHandler`) is `nova_events`.
Scenario events, filters, actions (modding events)	`nova_scenario`	`crates/nova_scenario/src/events.rs`, `crates/nova_scenario/src/filters.rs`, `crates/nova_scenario/src/actions/mod.rs`	`EventConfig`, `EventFilterConfig`, `EventActionConfig`	One dispatch enum each; actions fan out to the flow/mission/sequence/ship/spawn/timer/view submodules beside `mod.rs`.
Scenario variables, expressions, watches	`nova_scenario`	`crates/nova_scenario/src/variables.rs`, `crates/nova_scenario/src/world.rs`	`VariableExpressionNode`, `NovaEventWorld`	Typed literals + expression tree (`VariableConditionNode` for filters); watches sample typed world queries into variables.
Scenario objects (asteroid, spaceship, beacon, crate, light, anchor)	`nova_scenario`	`crates/nova_scenario/src/objects/mod.rs`, `crates/nova_scenario/src/actions/spawn.rs`	`ScenarioObjectsPlugin`, `ScenarioObjectKind`	One module per kind under `objects/`; the spawn action dispatches on the kind enum.
Scenario loading, lifetime scoping, teardown	`nova_scenario`	`crates/nova_scenario/src/loader/mod.rs`, `crates/nova_scenario/src/loader/lifecycle.rs`	`ScenarioLoaderPlugin`	`LoadScenario`/`UnloadScenario` observers; everything tagged `ScenarioScopedMarker` dies at teardown; `scenario_is_live` gates the ship sets.
Mod formats, bundles, portal	`nova_mod_format`, `nova_modding`, `nova_assets`	`crates/nova_mod_format/src/lib.rs`, `crates/nova_modding/src/lib.rs`, `crates/nova_assets/src/portal/mod.rs`	`BundleManifest`, `Content`, `PortalPlugin`	Engine-free serde wire types -> RON asset loaders -> portal fetch/verify/install. The static portal is generated by `scripts/gen-portal.py` over `webmods/`.
Content generation (base RON, builders, lint)	`nova_authoring`	`crates/nova_authoring/src/cli.rs`, `crates/nova_authoring/src/generation.rs`	`cli::main`	`cargo run content gen` serializes the `base_content` builders into the committed base `*.content.ron`; `content lint` validates any content tree. Never hand-edit generated RON.

Interface

Concept	Crate(s)	Key files	Entry symbol	Orientation
NOVA OS (terminal, shell, ship computer apps)	`nova_os`, `nova_os_ui`	`crates/nova_os/src/command.rs`, `crates/nova_os/src/app.rs`, `crates/nova_os_ui/src/lib.rs`	`NovaOsUiPlugin`	Pure model in `nova_os` (`NovaOsCommandRegistry`, `NovaOsAppRuntime`); the Tab CRT monitor and the map/ship apps in `nova_os_ui`.
Keybinds: the action table, rebinding, the capture	`nova_input`, `nova_menu`	`crates/nova_input/src/registry.rs`, `crates/nova_input/src/poll.rs`, `crates/nova_menu/src/settings.rs`	`InputBindings`, `InputSources`	One table of named actions; each owner registers its own defaults, every rig is BUILT from it, and every rebind surface reads it. Settings’ Controls tab takes the next press through `InputSources`; overrides persist in `settings_store`.
Flight HUD widgets	`nova_hud`	`crates/nova_hud/src/lib.rs`	`NovaHudPlugin`	One module per instrument (crosshairs, ammo, markers, comms, keybind dock); reads the ship, never drives it.
Main menu, menu backdrops	`nova_menu`	`crates/nova_menu/src/lib.rs`, `crates/nova_menu/src/ambience.rs`	`NovaMenuPlugin`	The backdrop is a random `menu_backdrop`-flagged scenario drawn live (`load_menu_ambience`); `NOVA_MENU_BACKDROP` pins one id for capture.
Shared UI theme, widgets, skins	`nova_ui`	`crates/nova_ui/src/lib.rs`, `crates/nova_ui/src/widget/mod.rs`	`NovaUiPlugin`	Theme tokens, the `UiSkin` switch, and the widget factories every UI-drawing crate consumes.
Ship editor, link points, placement	`nova_editor`, `nova_ship`	`crates/nova_editor/src/lib.rs`, `crates/nova_editor/src/snap.rs`, `crates/nova_ship/src/sections/link_points.rs`	`NovaEditorPlugin`	Sandbox build scene; `snap_placement` mates socket frames; the editor solver decides or refuses a drop.

Tooling

Depth: Automation harness, Measuring performance and Building and running.

Concept	Crate(s)	Key files	Entry symbol	Orientation
Automation harness, autopilot scripts, screenshot capture	`nova_autopilot`, `nova_debug`	`crates/nova_autopilot/src/autopilot.rs`, `crates/nova_debug/src/harness.rs`	`AutopilotPlugin`	Env-armed step driver (`NOVA_AUTOPILOT`, `NOVA_CAPTURE`); Nova presets and the `shoot` capture idiom live in the debug harness module.
Probe, run reports, what an example claims	`nova_probe`, `nova_probe_cli`	`crates/nova_probe/src/capabilities/mod.rs`, `crates/nova_probe/src/contract.rs`, `crates/nova_probe_cli/src/native.rs`	`NovaProbePlugin`	One bundle wires every capability; `probe run`/`scenario`/`report` (subcommands of the game binary, `debug` feature) spawn and grade runs. Web capture app: `crates/nova_perf_web/src/main.rs`.
Frame cost, scene census, the capture window	`nova_probe`	`crates/nova_probe/src/capabilities/frametime.rs`, `framecost.rs`, `census.rs`	`nova_frametime`, `nova_framecost`, `nova_census`	Wall-clock deltas over a fixed window, plus where the milliseconds went and what the scene contained. Knob table: `cargo doc -p nova_probe`.
World-state snapshot (read the world, not a render)	`nova_probe`	`crates/nova_probe/src/capabilities/snapshot.rs`	`nova_snapshot`, `probe_snapshot`	One JSON object per snapshot: ships, sections, fixtures, weapon state, rounds in flight. Sorted and rounded, so two snapshots of one frozen frame are byte-identical.
WFC arena, generated hulls	examples	`examples/playable/wfc_arena.rs`, `examples/playable/shared/wfc.rs`	`wfc_hull`	Wave-function collapse over real section prototypes into flyable hulls; the arena’s lobby/pause/result match flow sits in `examples/playable/wfc_arena/`.
Debug tooling (inspector, overlays, F12 screenshots)	`nova_debug`	`crates/nova_debug/src/lib.rs`	`DebugPlugin`	Compiled only under the `debug` feature; F11 overlay toggle, F12 screenshot, `--norender`, `--debugdump`.
Web preview, this book at /dev/	scripts, web	`scripts/serve-web.sh`, `scripts/preview-web.sh`, `web/webpack.config.js`	`serve-web.sh`	Live-serves site + `/play/` + `/mods/` + this book at `/dev/`, all watched; the preview script builds the static deploy shape.