Authoring Recipes

FUSE Authoring Recipes

This page answers the common “how do I do this?” questions. The JSON schema reference remains the field-by-field contract.

Start A Package

The easiest route is Tile Editor → New Mod. For hand-authored native data, create one package folder containing Info.json and one or more *.fuse.json files. Point FuseDataFiles at every fragment:

{
  "Id": "Author.Route",
  "DisplayName": "Author Route",
  "Author": "Author",
  "Version": "1.0.0",
  "ManagerVersion": "0.27.10",
  "Requirements": ["FUSE"],
  "LoadAfter": ["FUSE"],
  "FuseDataFiles": ["track.fuse.json", "industry.fuse.json"]
}

Use FuseRequires for a hard data-package dependency. Use FuseLoadAfter or FuseLoadBefore only for ordering. A missing hard dependency faults/skips the affected package and appears in /fuse.report; it must not break unrelated packages or game menus.

Move Or Replace Track

1. Open the package in Tile Editor and connect to the game.
2. Press F9, open Geo, then select the node or segment in the world.
3. Use the node/segment transform controls. The relationship list shows every segment using a selected node and both endpoints of a selected segment.
4. Save and force a track reload if the live preview ever differs from the selected JSON. The editor now rebuilds affected track objects after topology changes so stale copies do not accumulate.
5. Reopen the package and verify the same IDs and geometry before release.

Do not create a second segment with the same ID to replace the first one. FUSE uses atomic replacement for existing span/segment IDs so industries keep their references, but duplicate definitions inside one package are still authoring errors.

Remove A Base-Game Industry

Use the exact runtime industry ID, not its company-window display name:

{
  "schemaVersion": "1.0",
  "id": "Author.Route.industry-removals",
  "name": "Industry removals",
  "modVersion": "1.0.0",
  "operations": {
    "removals": {
      "industries": ["exact-runtime-industry-id"]
    }
  }
}

Run /fuse.dumpgraph and /fuse.dumpruntimegraph to find and compare IDs. The Tile Editor Operations page can discover/select industries, but manual JSON is still the safest way to remove a stock industry when the editor cannot identify an unambiguous owning layer.

Add Freight Loading Or Unloading

A rail industry component changes freight on cars spotted over a TrackSpan. It does not place a visible coal chute, water column, or fuel stand.

1. Create/select a town and industry in Tile Editor → F9 → Operations.
2. Create a whole, partial, or multi-segment TrackSpan from selected track.
3. Add a loader, unloader, formulaic, teamTrack, interchange, or other component to the industry.
4. Select the span and load ID, then configure capacity/rates.
5. Verify /fuse.operations and the company window in a new sandbox save.

Place A Visible Service Loader

Choose the implementation that matches the asset:

• An existing vanilla-style loader prefab that already contains Railroader's loader components can use native operations.loaders.
• A custom coal/water/diesel/bunker-C/wood facility should be placed through world.scenery, then bound with ToolshedServiceFacilities.json. Toolshed owns its outlet, animation, transfer, storage, and interaction behavior.

Do not split one custom facility between a scenery clone and an unrelated operations loader. That creates the “tank in one place, loading point in another” failure. The visible object and its service points must share the same placed root/transform contract.

Move A Base-Game Object Or Town Sign

Open F9 → Objects, disable Track Geometry if it blocks selection, then click the object. Save its move/rotate/scale/visibility override as a scene clone or mandela entry. Thin signs have a screen-space picking halo, and shared town/map roots are blocked so one click cannot move an entire scene hierarchy.

Edit Roads And Other Mandelas

Use Spliney for roads, rivers, bridges, and trestles. Base-game spline control points are editable; the first change writes a same-name override into the active layer. A legacy scene path such as World/Roads Sylva/Chipper Curve remains a scene path—it is not an asset identifier.

Use Objects/Mandela for individual scene objects and Scenery for asset-pack models. They have different ownership and runtime rebuild paths.

Build A Fence, Retaining Wall, Or Other Repeated Object Line

Use a native world.splineys entry with type: "objectLine". This samples a path at uniform spacing and places rigid modules; it does not stretch a fence panel or retaining-wall block into a distorted mesh.

{
  "world": {
    "splineys": {
      "yard:fence:north": {
        "type": "objectLine",
        "assetIdentifier": "your-pack:fence-panel",
        "spacing": 3.0,
        "instanceScale": { "x": 1, "y": 1, "z": 1 },
        "rotationOffset": { "x": 0, "y": 90, "z": 0 },
        "lateralOffset": 0,
        "verticalOffset": 0,
        "snapToTerrain": true,
        "alignToSlope": false,
        "placeAtEnd": true,
        "maximumInstances": 1024,
        "points": [
          { "position": { "x": 10, "y": 2, "z": 15 } },
          { "position": { "x": 55, "y": 3, "z": 22 } }
        ]
      }
    }
  }
}

Choose exactly one source: assetIdentifier is portable and recommended; prefab accepts a safe FUSE prefab/scene-path URI for advanced stock-object cloning. The Tile Editor exposes this as Geo → Spliney → Fence / Wall and rebuilds the repeated modules while its point handles remain editable. This is native FUSE only; the legacy RailLoader spline schema has no equivalent.

Conditional Legacy Mixins

Converted conditional fragments use mixinto.requires:

{
  "mixinto": {
    "target": "game-graph",
    "sourceFile": "OptionalYard.json",
    "requires": [
      { "id": "Author.BaseYard", "notBefore": "1.2.0" }
    ]
  }
}

When the dependency is missing or outside the allowed range, FUSE skips this fragment and reports the package, folder, source file, dependency ID, and action. loadAfter is ordering and must not be flattened into a hard requirement.

Package Options And Modular Mods

Top-level settings creates controls in FUSE's per-mod settings page. Native code can read them through FuseModSettingsAPI. The current v1 data schema does not yet make arbitrary JSON sections conditional on a setting, so do not imply that a slider automatically enables track/spans. Until a declarative condition format is released, use separate optional data packages/fragments with explicit dependencies, or a small independently authored code component that reads the setting and applies supported API operations.

Diagnose Bad JSON

Run /fuse.report for a readable report or /fuse.report json for structured output. A definition failure includes:

• package ID
• absolute package folder and source file
• JSON path
• line and column when Newtonsoft can provide them
• validation code/message
• suggested action

FUSE isolates the bad definition and continues loading unrelated packages. Fix the first syntax error first; later errors can be consequences of that one.

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