This guide takes you from a fresh Untold Engine checkout to a working game
project. You will run the demo, create an Xcode project, export assets into the
engine's .untold runtime format, and load those assets from a GameScene.
You can create projects and export assets in two ways:
- Use the CLI if you prefer terminal commands or want a repeatable workflow.
- Use Untold Engine Studio if you prefer a visual editor for project setup, asset import, and scene preparation.
After your project is created, both workflows lead to the same place: an Xcode
project with a GameData folder that contains the assets your game loads at
runtime.
Clone the repository and launch the demo:
git clone https://github.com/untoldengine/UntoldEngine.git
cd UntoldEngine
swift run untolddemoYou can create a project with either Untold Engine Studio or the CLI. If you are new to Untold Engine, start with the Editor. If you prefer terminal workflows or want repeatable project setup, use the CLI.
Use Untold Engine Studio for a visual workflow. It is a standalone editor for creating projects, preparing assets, composing scenes, and generating scene files used inside your game.
To set up a project:
- Click on "New".
- Provide a Project name
- Provide a Bundle name
- Select the Target Platform
- Provide an output path
Untold Engine Studio will create an Xcode project ready to be used with Untold Engine.
Use untoldengine-create to generate a ready-to-run Xcode project with Untold Engine wired in.
Install it from the repository:
./scripts/install-untoldengine-create.shNow create an Xcode project. The example below uses --platform visionos to
create a Vision Pro project.
cd ~/Projects
untoldengine-create create VisionGame --platform visionos
open VisionGame/VisionGame.xcodeprojIf you want to create a project for other platforms, you can use the flags below:
# visionOS (Apple Vision Pro)
untoldengine-create create MyGame --platform visionos
# macOS (default)
untoldengine-create create MyGame --platform macos
# iOS with ARKit
untoldengine-create create MyGame --platform ios-ar
# iOS
untoldengine-create create MyGame --platform iosDependency behavior by platform:
visionos:UntoldEngineXR+UntoldEngineARios-ar:UntoldEngineARiosandmacos:UntoldEngine
Untold Engine uses .untold as its native runtime asset format. USDZ/USD remains
the authoring format — you model assets in your DCC tool, export to USDZ, then
convert to .untold before loading them in the engine.
The .untold format is a binary container optimised for fast runtime parsing with
no ModelIO dependency. It supports runtime mesh data, PBR materials, texture references,
transforms, bounds, and exported animation clips.
Note: The exporter requires Blender.
You can convert assets with either Untold Engine Studio or the CLI. If you are new to Untold Engine, start with the Editor. If you prefer terminal workflows or need repeatable asset export commands, use the CLI.
To convert a USDZ file into the .untold format using the editor:
- Click on "Import" in the Asset Browser View.
- Click on "Import Models"
- Find a USDZ file you want to convert
- Click on Export
- When the export has completed, you will see your new
.untoldmodel under the Model Category
At this point, head over to your Xcode project. You will also notice that your .untold model is under Sources/<ProjectName>/GameData/Models.
Use the export-untold script to convert a single USDZ asset:
./scripts/export-untold \
--input /path/to/your/model/robot/robot.usdz \
--output /path/to/your/project/GameData/Models/robot/robot.untold \
--ConvertOrientation \
--source-orientation blender-nativeFor animation assets, use the --animation flag:
./scripts/export-untold \
--input /path/to/your/animation/robot/robot.usdz \
--output /path/to/your/project/GameData/Animations/robot/robot.untold \
--ConvertOrientation \
--source-orientation blender-native \
--animationFor large scenes that need tile-based streaming, use export-untold-tiles to
partition the scene and generate a manifest JSON:
./scripts/export-untold-tiles \
--input /path/to/your/model/dungeon/dungeon.usdz \
--output-dir /path/to/your/project/GameData/StreamModels/dungeon/tile_exports \
--tile-size-x 25 \
--tile-size-z 25 \
--generate-hlod \
--generate-lodFor the full list of options, validation flags, and expected output layout see Using The Exporter. For optional asset optimization workflows, see Optimizations.
Once in your Xcode project, head over to the init function in Sources//GameScene.swift.
Use setEntityMeshAsync to load an .untold file as an always-resident asset.
This is the right choice for props, characters, and any object that should stay
in memory for the lifetime of the scene.
//...After configureEngineSystems()
let entity = createEntity()
setEntityName(entityId: entity, name: "robot")
setEntityMeshAsync(entityId: entity, filename: "robot", withExtension: "untold") { success in
if success {
translateBy(entityId: entity, position: simd_float3(0.0, 0.0, 0.0))
setEntityKinetics(entityId: entity)
}
setSceneReady(success)
}setEntityMeshAsync is non-blocking. The completion block fires on the main thread
once the mesh is parsed and uploaded to GPU memory.
Use setEntityStreamScene to load a large scene that streams tiles in and out of
GPU memory based on camera proximity. Pass either a local manifest path or a remote
https:// URL — the engine handles downloading and caching automatically.
//..After configureEngineSystems()
let sceneRoot = createEntity()
setEntityName(entityId: sceneRoot, name: "dungeon")
// Local manifest
setEntityStreamScene(entityId: sceneRoot, manifest: "dungeon", withExtension: "json") { success in
setSceneReady(success)
}To streame a remote scene, you use the same function setEntityStreamedScene() but provide a url to your manifest json file.
// Remote manifest (downloaded and cached on demand)
if let url = URL(string: "https://cdn.example.com/dungeon/dungeon.json") {
setEntityStreamScene(entityId: sceneRoot, url: url) { success in
setSceneReady(success)
}
}setEntityStreamScene registers lightweight stub entities for every tile in the
manifest, all parented under sceneRoot (no geometry is parsed at this point).
GeometryStreamingSystem then loads and unloads tile geometry as the camera moves.
See Tile-Based Streaming for the full streaming
architecture.
Legacy overloads —
loadTiledScene(manifest:)andloadTiledScene(url:)remain available for backwards compatibility. They create an internal root entity automatically.
Retrieve a named entity with findEntity(name:) inside the completion block or
after setSceneReady:
setEntityMeshAsync(entityId: entity, filename: "stadium", withExtension: "untold") { success in
if let player = findEntity(name: "player") {
rotateTo(entityId: player, angle: 0, axis: simd_float3(0.0, 1.0, 0.0))
setEntityKinetics(entityId: player)
}
setSceneReady(success)
}Create a camera and directional light manually in your scene setup, then position the camera after assets load:
let gameCamera = createEntity()
setEntityName(entityId: gameCamera, name: "Main Camera")
createGameCamera(entityId: gameCamera)
CameraSystem.shared.activeCamera = gameCamera
let light = createEntity()
setEntityName(entityId: light, name: "Directional Light")
createDirLight(entityId: light)After loading:
moveCameraTo(entityId: findGameCamera(), 0.0, 3.0, 10.0)
ambientIntensity = 0.4A complete GameScene using the patterns above:
final class GameScene {
init() {
// Camera and light
let gameCamera = createEntity()
setEntityName(entityId: gameCamera, name: "Main Camera")
createGameCamera(entityId: gameCamera)
CameraSystem.shared.activeCamera = gameCamera
let light = createEntity()
setEntityName(entityId: light, name: "Directional Light")
createDirLight(entityId: light)
// Load a single always-resident asset
let stadium = createEntity()
setEntityMeshAsync(entityId: stadium, filename: "stadium", withExtension: "untold") { success in
if let player = findEntity(name: "player") {
rotateTo(entityId: player, angle: 0, axis: simd_float3(0.0, 1.0, 0.0))
setEntityAnimations(entityId: player, filename: "running", withExtension: "untold", name: "running")
setEntityAnimations(entityId: player, filename: "idle", withExtension: "untold", name: "idle")
setEntityKinetics(entityId: player)
}
moveCameraTo(entityId: findGameCamera(), 0.0, 3.0, 10.0)
ambientIntensity = 0.4
setSceneReady(success)
}
}
}For a large streaming scene, replace the setEntityMeshAsync call with setEntityStreamScene:
let sceneRoot = createEntity()
setEntityName(entityId: sceneRoot, name: "dungeon")
setEntityStreamScene(entityId: sceneRoot, manifest: "dungeon", withExtension: "json") { success in
moveCameraTo(entityId: findGameCamera(), 0.0, 3.0, 10.0)
ambientIntensity = 0.4
setSceneReady(success)
}