Sandbox world profiles

Packs can register extra sandbox world types that appear in the Sandbox menu beside built-in options (New Earth, Asteroid, Prefab Build, …). Generation still uses the New Earth terrain system; the pack supplies alternate world-gen details, spawns, and a data-driven sky.

Files

File	Role
worldprofile_*.json	Menu entry, icon, world-gen path, spawn name, recommended size, options
WorldGenerator/WGD_*.json	Foreground world-gen details (passes, flatness, prefabs, …)
WorldGenerator/WGBD_*.json	Optional background tile layers (referenced from the WGD file)
Spawning/SPWN_*.json	Ambient spawn groups; Name must match SpawnDetailsName
Parallax/parallax_*.json	Optional sky definition (layers, celestials, clouds, lighting)
Pack icon PNG	Sandbox type picker art (IconPath)

Stock terrain passes remain available by their built-in ids. Stock skies live in the game’s parallax content; every world type (including built-ins) loads through the same sky system.

Stock Asteroid and Xenoid Bauble intentionally use separate sky definitions: they share the same hill art, but Asteroid is fixed-noon while Xenoid retains its day/night lighting cycle.

worldprofile_*.json shape

{
  "WorldProfile": {
    "UniqueIdentifier": "moon",
    "DisplayName": "Moon",
    "Description": "…",
    "IconPath": "WorldGenerator/icon_moon.png",
    "WorldGenDetailsPath": "WorldGenerator/WGD_Moon.json",
    "SpawnDetailsName": "Moon",
    "RecommendedMapSize": "SMALL",
    "ParallaxDefinitionPath": "Parallax/parallax_moon.json",
    "GravityScale": 0.1654,
    "SkipEarthSurfaceDecor": true
  }
}

The runtime id is UniqueModName.UniqueIdentifier (for Example Mod: ExampleMod.moon). That string is stored on the world save so the game knows which pack profile to load.

Field	Notes
RecommendedMapSize	Defaults the size picker only. Players can still change size.
ParallaxDefinitionPath	Pack-relative sky JSON (preferred). Horizon tracks the world’s ground level.
ParallaxStyle	Optional shorthand: NEW_EARTH, ASTEROID, HEPHAESTUS, PREFAB_BUILD, MOON.
GravityScale	Surface gravity as a fraction of Earth (1.0 = Earth). Luna ≈ 0.1654.
SkipEarthSurfaceDecor	Skip tall grass / ground scatter / flora post-steps.

Example Mod samples

With Example Mod enabled:

Profile	Idea
Flatlands	Full New-Earth-like authoring surface, flatter seating, recommended SMALL
Moon	Minimal marble terrain, pack space sky, Luna gravity, no Earth surface decor

Validate the pack with Mod Prep before publishing.

Authoring the terrain

See Authoring world-gen details for WGD fields, Flatlands vs Moon recipes, flatness/prefabs, sky/horizon tips, and a publish checklist.

Saves and multiplayer

• Built-in worlds do not store a pack profile id.
• Pack worlds remember that they were created from a pack profile.
• Loading a pack world without that pack enabled is refused (no silent fall-back to New Earth).
• Multiplayer still requires matching game version; peers need the same pack for that world type.

Authoring tips

• Prefer a pack ParallaxDefinitionPath over borrowing Asteroid altitude math for Earth-pipeline surfaces.
• Map size is chosen in the Sandbox menu — do not encode size in the profile display name.
• For pass lists, flatness, prefabs, and horizon modes, use Authoring world-gen details.