Custom maps

STUNTBOOST supports custom levels made in Blender with the exporter that ships in the install (StuntboostTools/, which the developers also publish on GitHub). The exporter bakes the lighting, writes glTF files and puts them where the game looks. Sourced · StuntboostTools This is separate from the game’s own levels, which are XNB-wrapped.

Where a map lives

A map is a folder under the game’s custom_maps directory in the save-game area: %APPDATA%/STUNTBOOST/custom_maps/<map> on Windows, ~/.config/STUNTBOOST/custom_maps/<map> on Linux (or under $XDG_CONFIG_HOME). The exporter creates the folder. If it exists, a CUSTOM LEVELS button shows in the room selection (custom levels are otherwise hidden), and the Custom screen has an Open maps folder button. Sourced · StuntboostTools A map folder is shared by zipping it and unpacking it into another custom_maps. Sourced · StuntboostTools Exporting again reloads the active custom map and restarts the run while the game is running. Sourced · StuntboostTools

What a map holds

File	Content	Confidence
<level>.gltf (one or more parts)	glTF 2.0 JSON; triangles only	Observed · STUNTBOOST
external .bin files	the glTF buffers	Observed · STUNTBOOST
external PNG files	the images; embedded images are refused	Observed · STUNTBOOST
exactly one <level>_.json	the metadata (below)	Observed · STUNTBOOST

The game compiles the collision itself from the glTF; no Collision.xnb is needed. Observed · STUNTBOOST The map needs a node =Spawn(start) or =Spawn() (node names). Sourced · StuntboostTools An unknown class in a node shows as a red wireframe box. Sourced · StuntboostTools

The metadata file

<level>_.json is the same sidecar a built-in level has (modelCount), with optional fields. Observed · STUNTBOOST

Field	Meaning
modelCount	the number of parts
id	a UUID, the map’s identity; without it moving or renaming the folder changes the map’s id
version	an integer; increase it for a new record version
name	the displayed title; falls back to the file name
author	the displayed name; falls back to Unknown
preview	path to a PNG inside the map folder shown in the level selection
medalTimesSeconds	targets in seconds, positive, silver ≥ gold ≥ diamond ≥ obsidian ≥ developer

All Sourced · StuntboostTools. A rejected file is explained in the game’s Map errors list. Sourced · StuntboostTools There is no online leaderboard or replay for custom maps. Sourced · StuntboostTools

The exporter

The exporter is a set of Blender add-ons (StuntboostTools/blender_addons) for a modified Blender 4.3.2 (a custom build that adds a multi-core pre-bake step, baking several passes at once, a fix for black borders in denoised bakes and a Cycles Color Spill setting); newer Blender versions up to 5.2 are reported to work with fallbacks. Sourced · StuntboostTools A successful export ends with EXPORT FINISHED; a scene has Level and Room bake groups and a Skybox scene (levels). Sourced · StuntboostTools The game’s own pipeline tool is a dotnet tool, bytinggames-dotnet-mgcb 3.8.1.49 (mgcb-byting), listed in the install’s ContentMod folder. Observed · STUNTBOOST

The documentation lists as not implemented: changing the vehicle type, wheels, eyes and doors, godrays and fog; and as not yet documented: creating own assets, detours and shortcut detection, the entity name language (physics delete, material replace, rename logic, outline magic) and overriding post-processing and colour grading. Sourced · StuntboostTools

Whether the game accepts a custom map’s collision as it does a shipped level’s

Custom maps carry glTF only and the game builds collision for them; how that build compares with the pipeline’s derived file for a shipped level (the same node rules, ledge detection and grid) is not established.