Map Authoring Coverage

Railroader base-game map-authoring audit

This audit compares the observable Railroader map contract in the decompiled 2026.1 source with FUSE native schema, FUSE runtime behavior, and both Tile Editor surfaces. Decompiled code is used only to identify public data shapes, identifiers, initialization order, and observable behavior; no implementation code is copied.

The installed game on the audit machine still exposes the earlier Unity TrackSegment.Style contract. The 2026.1 source changes track objects and uses combinable structure flags. Compatibility therefore has two distinct gates:

1. Native documents must retain every known field now.
2. A FUSE/editor binary compiled for a released game generation must pass its own live acceptance run. A source audit is not evidence that an unreleased binary contract already works in game.

Coverage matrix

Base-game concern	Observable contract	FUSE/editor coverage	Remaining acceptance
Map identity and launch	MapDefinition supplies map data, terrain tile sets, layers, and attribution; a session selects one registered map	Native map declaration, registered-map browser, launch command, map identity/start-state authoring, standalone-map golden fixture	Launch the generated fixture, save, reload, and reopen it in both editors
Layering	Base data plus JSON merge-patch layers; tombstones remove inherited values	FUSE owns its canonical native document and explicit removals; legacy mixintos convert at the boundary; native modular feature rules conditionally apply authored objects	Mixed native/legacy live reload and one full generated-map round trip
Folders	Map folders group objects/spawns and folder enabled state gates them	FUSE feature groups provide stronger package-owned conditional gating; editor retains unknown official-map fields when editing	Add an official-map import crosswalk so folder names/enabled state are visible instead of opaque retained data
Map objects	Registered DTO kinds include scenery, circle/rectangle/curve masks, and built-ins	Native scenery, masks, labels, scene clones, telegraph, water, splineys, and object lines; selectable base objects and town signs	Dense-scene object picking and stock-object move/remove live pass
Built-in car loader	Built-in id + track anchor + parameters, including infinite or industry supply	Native operations loaders plus Toolshed custom service bindings, track/span snap, offsets, source industry and load points	Live loading/unloading, storage, payment, and custom-model pass
Built-in spline loft	Ordered control points, point width/rotation, width/Y offsets, end extension, cap falloff, and generated mesh; used by road/river content	Deformable road/river splineys plus rigid repeated-object lines for fences, walls, guardrails, and pipes	Profile/material family inventory, cap/falloff UI acceptance, and in-game save/reload
Terrain tiles	Height, splat, vegetation, statistics, streaming and map tile-set ownership	Tile import/download workflow, sculpt/paint, categorical vegetation masks, atomic save/backup, statistics rebuild, cache invalidation, terrain registration	Seam/falloff/undo fidelity and live paint-save-reload across adjacent tiles
Water	Lake polygons/flat water surfaces reuse game material/profile data; rivers can also be spline-driven	Native water surfaces with CRUD, stock replacement, point editing, schema, validation, diagnostics; river spline authoring	Reflection/collider/material behavior and save/reload in game
Track nodes	Position, rotation, switch-stand flip, and diamond-crossing state	Native position/rotation/flip plus additive isDiamond; converter and editor preserve the field	Diamond routing/rendering in the game build that exposes it
Track segments	Endpoints, group, priority, speed, class, style or newer bridge/steel/tunnel/yard flags	Existing style stays canonical for released builds; additive steel-support and independent-yard metadata preserve the newer contract; gauge metadata, groups, grade labels, validation	Compile/run against the released flags-era assembly; live bridges, tunnels, yards, and DKW/crossing geometry
Turntables	Transform, radius, subdivisions, node ids, default stop and bridge group	Native turntable authoring and editor workflow	Custom model/track alignment, roundhouse, save/reload live pass
Track spans and areas	Locations anchor by segment/end/distance; areas group spans and UI/operations identity	Native spans/areas, normalization, node/segment relationships, orphan validation, legacy repair/rebinding	Sylva/Kater base-span cases and delivery/highlight/payment agreement
Industry operations	Areas, industries, loads, contracts, components, storage, loaders/unloaders, teams, interchange, passenger/timetable services	Native models, editors, schema, pre-publish cross-file validation, package-local fault reporting	Every component kind, EOD processing, contract changes and company-window live pass
Passenger service	Stops, span membership, agents/timetables and neighboring-stop caches	Native passenger/station models, invalid-span sanitation, editor workflows and validation	Neighbor reconciliation, timetable/UI, save/reload and modded-map live pass
Interchanges	Industry/service components, track/span routing and exchange behavior	Native interchange editor/runtime models and compatibility shims	Multi-interchange ordering, inbound/outbound/EOD and legacy interchange corpus
Signals and CTC	Signals, heads/aspects, blocks, routes, switch locks, interlockings and CTC panel components	Portable signal/CTC schema and runtime, editor placement/routes/blocks/dispatcher panel, cross-file validation	Native FUSE ownership, broader signal/custom-asset families, and a complete live territory
Progression	Map features, milestones, gating, industry/track availability and starting state	Native progression, transfer diagnostics, feature options and start-equipment scoping	Fresh career/sandbox reload behavior and complete generated-map progression pass
Starting equipment	Session setup places starting cuts and tutorial owns early UI flow	Package/map-scoped equipment pool; tutorial wait; cancellation retains queued cuts; successful placement requires full car count	Unrelated-new-save test and tutorial/Escape/cancel/resume/place live pass
Spawns/portals	Spawn DTOs and map bootstrap locations; interchange/portal concepts participate in session creation	Native spawn/start-point and interchange authoring in the complete-map fixture	Multiple spawn choices and portal/interchange launch behavior in game
Save identity	Stable object ids, graph ids, KVO/save identities and post-load binding are required	Stable native ids, duplicate/collision validation, atomic writes, backups, undo/redo, runtime definition cache	Generated map save, reload, edit, re-export and second reload
Runtime caches	Terrain, graph, scenery, operations and UI caches have subsystem-specific invalidation/rebuild order	Targeted track rebuild, terrain invalidation, scenery/asset indexes, operations refresh, live diagnostics and test bridge	Every-tab live acceptance using the newest deployed DLL
Multiplayer authority	Several operations/signals/session changes are authority-sensitive	Signal/CTC portable model includes multiplayer state; most authoring runs on local editor/session	Host/client ownership and synchronization pass

Canonical FUSE track additions from this audit

The following properties are additive and do not change existing native documents:

• tracks.nodes.<id>.isDiamond
• tracks.segments.<id>.bridgeSupportsSteel
• tracks.segments.<id>.yard
• the corresponding preserveBridgeSupportsSteel and preserveYard controls for partial legacy overlays

Legacy numeric flags are decoded at conversion time. Existing style values remain valid and continue to drive the installed released game. Editors update copies of node/segment objects so unknown companion and future fields survive ordinary position/property edits.

What a from-scratch map must prove

A map-authoring release is accepted only when one fixture completes this whole sequence without hand-editing:

1. Create map identity, attribution and coordinate/tile set.
2. Acquire/import adjacent terrain tiles and preserve source/licensing data.
3. Sculpt terrain, paint texture/vegetation, add/edit water, then save/reload.
4. Lay main, branch, yard, bridge/tunnel, turnout, crossing, span, group, turntable and interchange track; inspect grades and node relationships.
5. Add roads/rivers plus rigid fence/wall/guardrail/pipe object lines.
6. Add scenery, masks, labels, town signs, loaders and custom Toolshed models.
7. Configure areas, loads, industries, contracts, storage, delivery/payment, passenger service, interchange service and progression.
8. Build a working signal territory and CTC panel with routes/interlockings.
9. Configure spawn/start state and package-scoped starting equipment.
10. Validate, export, install, launch, operate, save, reload, reopen in the editor, change content, re-export and reload again.
11. Repeat from the published wiki using a clean installation.

Automated fixtures currently prove document creation, validation, export and reopen. The live stages remain deliberately separate so a green unit test can never be mistaken for rendered/operational proof.

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Mirrored from docs/BASE_GAME_MAP_AUTHORING_AUDIT.md — edit there, not here.