Untold Engine is an open-source 3D engine written in Swift and powered by Metal, designed for Apple platforms including macOS, iOS, and visionOS.

The project focuses on building a clean and approachable architecture with modern rendering, an ECS-based gameplay model, and an extensible asset pipeline.

The engine is under active development and continues to evolve as new systems and workflows are added.

Creator & Lead Developer:
http://www.haroldserrano.com

The fastest way to experience Untold Engine is to run the demo project.

Clone the repository and run the demo:

git clone https://github.com/untoldengine/UntoldEngine.git
cd UntoldEngine
swift run DemoGame

This will:

• Build the engine using Swift Package Manager
• Compile the demo project
• Launch the demo so you can see the engine running immediately

No additional setup is required.

Click the image below to watch the engine in action.

• Apple Platform Coverage: Unified Swift + Metal codebase for macOS, iOS, and visionOS
• Rendering Pipeline: Metal renderer with PBR/IBL workflows and post-processing across standard and XR paths
• AR and XR Runtime Support: Built-in AR workflows plus visionOS integration and spatial interaction support
• ECS + Scene Graph Core: Component-based architecture with hierarchical transforms and scene root transform controls
• Async Content Loading: Asynchronous loading pipeline for scenes and assets to improve responsiveness on large worlds
• LOD and Streaming: LOD support with geometry streaming, streaming regions, and memory budget management
• Static Batching and Culling: Static batching, octree acceleration, and occlusion culling for large-scene performance
• Advanced Picking: Scene, ground, and GPU ray picking with octree-backed intersection paths
• Spatial Input Features: XR spatial input helpers including anchored pinch drag, distance tracking, and two-hand rotation
• Scripting System (USC): Untold Script Core with multi-script support plus camera, math, and physics APIs (Experimental)
• Gameplay Systems: Physics, animation, camera waypoint, and input systems (keyboard, mouse, touch, and gamepad)
• Gaussian Splat Rendering: Native Metal support for rendering and compositing 3D Gaussian content
• Tooling Integration: Optional Untold Editor workflow and Swift Package Manager integration

The Untold Engine project includes several related components.

Standalone application that includes:

• Visual editor
• Full engine integration
• Asset management tools

Download:

https://github.com/untoldengine/UntoldEditor/releases

Ideal for developers who want to create games using the editor.

Contains the core engine systems:

• Rendering
• ECS architecture
• Physics and animation
• Scene graph
• Input systems

This repository is primarily for:

• Engine contributors
• Developers studying the engine architecture
• Users running demo projects

The visual editor used for managing assets, scenes, and workflows.

Repository:

https://github.com/untoldengine/UntoldEditor

For guides and API documentation visit:

https://untoldengine.github.io/UntoldEngine

You will find:

• Tutorials for using the engine
• Architecture documentation
• Setup instructions
• Guides for common tasks

If you prefer working from the terminal, you can use the project creation CLI.

Install it from the repository:

git clone https://github.com/untoldengine/UntoldEngine.git
cd UntoldEngine
./scripts/install-create.sh

Then create a new project:

mkdir MyGame
cd MyGame
untoldengine-create create MyGame

Features:

• Create macOS, iOS, and visionOS projects
• Multi-platform project templates
• Automated project structure generation

See open issues for planned features and improvements.

Feature Requests
https://github.com/untoldengine/UntoldEngine/issues?q=label%3Aenhancement

Bug Reports
https://github.com/untoldengine/UntoldEngine/issues?q=label%3Abug

For help or questions use GitHub Issues.

https://github.com/untoldengine/UntoldEngine/issues

Contributions are welcome.

You can help by:

• Fixing bugs
• Improving systems such as rendering, physics, or ECS
• Writing documentation
• Proposing new ideas

Before submitting a pull request please read:

• CONTRIBUTING.md
• CONTRIBUTOR_LICENSE_AGREEMENT.md

All contributions are licensed under MPL-2.0.

To ensure the long-term sustainability of the project, contributors must agree to the CLA.

By submitting a pull request you agree that your contributions may be distributed under the Mozilla Public License 2.0.

See:

CONTRIBUTOR_LICENSE_AGREEMENT.md

A huge thanks to the people helping shape the Untold Engine.

Untold Engine is licensed under the Mozilla Public License 2.0 (MPL-2.0).

This allows developers to build commercial applications while ensuring improvements to the engine itself remain open.

Full license text:

https://www.mozilla.org/MPL/2.0/

“Untold Engine” and the Untold Engine logo are trademarks of Untold Engine Studios.

Forks may not use the name in a way that implies official endorsement.

See:

TRADEMARKS.md

Use GitHub Discussions for ideas and questions:

https://github.com/untoldengine/UntoldEngine/discussions

Use GitHub Issues for bugs and tasks:

https://github.com/untoldengine/UntoldEngine/issues