Table of Contents
The Untold Engine strives to be a stable, performant, and developer-friendly 3D engine that empowers creativity, removes friction, and makes game development feel effortless for Apple developers
The Untold Engine is an open-source 3D game engine under active development, designed for macOS and iOS platforms. Written in Swift and powered by Metal, its goal is to simplify game creation with a clean, intuitive API. While the engine already supports many core systems like rendering, physics, and animation, there’s still much to build and improve.
Creator & Lead Developer: Harold Serrano
Click on image to play video:
- Cross-Platform Support: Runs on macOS, iOS, and visionOS using a unified Swift + Metal codebase.
- Modern Renderer: Built on Metal with support for PBR materials, IBL, post-processing effects, and efficient GPU resource management.
- Entity–Component–System (ECS): Lightweight ECS architecture for organizing game logic and behaviors cleanly.
- Scene Graph: Hierarchical transformation system for managing parent–child relationships between entities.
- Physics System: Includes Euler integration, motion systems, and component-based extensibility for collisions and constraints.
- Animation System: Supports skeletal animations and reusable animation clips.
- Input System: Unified keyboard, mouse, and touch input handling (with controller support planned).
- Gaussian Splat Rendering: Native support for rendering 3D Gaussian Splats with Metal, enabling photorealistic scene reconstruction and novel view synthesis.
- Untold Editor Integration: Optional visual editor for managing assets, entities, and scenes.
- Swift Package Manager (SPM): Fully modular — integrate it easily into your own Xcode or Swift projects.
-
- Open Source & Extensible: Licensed under the Mozilla Public License 2.0 (MPL-2.0), encouraging collaboration while protecting improvements to the engine core.
The Untold Engine is a work in progress, with ambitious goals to:
- Extend the physics and collision system.
- Add advanced lighting and reflections.
- Expand XR and input support for visionOS.
- Improve workflow between the engine, editor, and asset pipeline.
The Untold Engine project consists of multiple components designed for different audiences:
- What it is: Standalone application (DMG download)
- Includes: Visual editor + scripting + full engine + all dependencies
- Target audience: Game developers who want to create games
- Get it: Download releases
- No coding/building required — just install and start creating
- What it is: Core engine repository (this repo)
- Contains: Rendering, physics, ECS, animation, input systems
- Target audience: Developers contributing to the engine core
- Get it: Clone UntoldEngine
- Purpose: Improve or extend the engine's fundamental systems
- What it is: Editor interface repository
- Contains: Visual editing tools, UI, asset management
- Target audience: Developers contributing to the editor
- Get it: Clone UntoldEditor
- Purpose: Improve the editor interface and workflows
Quick guide:
- Making games? → Download Untold Engine Studio
- Contributing to engine core? → Clone Untold Engine
- Contributing to editor? → Clone Untold Editor
For comprehensive guides and API documentation, visit:
👉 Untold Engine Docs
You'll find:
- Game developers: Tutorials on using Untold Engine Studio
- Contributors: Architecture guides and API references
- Installation & setup for both users and developers
- How-to guides for common tasks
⚡ New to game development with Untold Engine? Download Untold Engine Studio and check out the Getting Started guide.
Want to make games? Download Untold Engine Studio — a complete standalone application that includes:
- ✅ Visual editor with scripting support
- ✅ Full Untold Engine integration
- ✅ Asset management and scene editing
- ✅ Everything you need to create games
- ✅ No build tools or GitHub required
👉 Download Untold Engine Studio
Just download the DMG, install, and start creating your game!
Prefer the command line? Use untoldengine-create — an optional CLI tool for creating game projects without the editor:
# Clone the repository
git clone https://github.com/untoldengine/UntoldEngine.git
cd UntoldEngine
# Install the CLI globally
./scripts/install-create.sh
# Create a game project from anywhere
cd ~/anywhere
mkdir MyGame && cd MyGame
untoldengine-create create MyGameFeatures:
- ✅ Create projects for macOS, iOS, iOS AR, visionOS, and multi-platform
- ✅ Multi-platform: One project for macOS, iOS, and visionOS
- ✅ Automated asset folder structure creation
- ✅ Perfect for CI/CD pipelines and scripting
- ✅ Update existing projects without touching custom code
Want to contribute to the engine core? This repository contains the engine's fundamental systems:
- Rendering (Metal-based)
- Physics and collision detection
- Entity-Component-System (ECS)
- Animation and scene graph
- Input handling
Clone this repository if you want to improve or extend the engine itself.
See the open issues for a list of proposed features (and known issues).
- Top Feature Requests (Add your votes using the 👍 reaction)
- Top Bugs (Add your votes using the 👍 reaction)
- Newest Bugs
Reach out to the maintainer at one of the following places:
If you want to say thank you or/and support active development of Untold Engine:
- Add a GitHub Star to the project.
- Tweet about the Untold Engine.
- Write interesting articles about the project on Dev.to, Medium or your personal blog.
Together, we can make Untold Engine better!
We welcome contributions to Untold Engine.
You can contribute in many ways:
- Fix Bugs – Help resolve issues reported by the community.
- Improve Features – Enhance existing systems such as rendering, physics, ECS, or XR support.
- Write Documentation – Tutorials and guides help new developers learn the engine faster.
- Propose New Ideas – Share ideas through GitHub Discussions.
Before submitting a pull request, please read:
- CONTRIBUTING.md
- CONTRIBUTOR_LICENSE_AGREEMENT.md
All contributions to Untold Engine are licensed under the Mozilla Public License 2.0 (MPL-2.0).
To ensure the long-term sustainability of the project, all contributors must agree to the project's Contributor License Agreement (CLA).
By submitting a pull request, you agree that your contributions may be distributed under the Mozilla Public License 2.0 (MPL-2.0).
See:
CONTRIBUTOR_LICENSE_AGREEMENT.md
A huge thanks to the people helping shape the Untold Engine. Your support and contributions make the project better every day.
Untold Engine is licensed under the Mozilla Public License 2.0 (MPL-2.0).
This license allows developers to build commercial applications with Untold Engine while ensuring that improvements made to the engine itself remain open.
| You want to… | Allowed? | Obligations |
|---|---|---|
| Build a game using Untold Engine | ✅ Yes | Your game code can remain proprietary |
| Use Untold Engine in commercial projects | ✅ Yes | No royalties required |
| Modify the Untold Engine source code | ✅ Yes | Modified engine files must remain MPL-2.0 |
| Create plugins or external tools | ✅ Yes | Plugins can use any license |
MPL-2.0 strikes a balance between openness and flexibility:
- Protects improvements to the engine core
- Allows proprietary games, apps, and plugins
- Encourages a healthy open ecosystem
See the full license text in the LICENSE file or visit:
https://www.mozilla.org/MPL/2.0/
“Untold Engine” and the Untold Engine logo are trademarks of Untold Engine Studios.
You may use the name to reference the project or describe software built with the engine.
However, forks or derivative projects may not use the name in a way that implies official endorsement.
See:
TRADEMARKS.md
To keep communication clear and accessible for everyone:
- 💡 Use GitHub Discussions for feature proposals, ideas, or general questions.
- 🐞 Use GitHub Issues for bugs or concrete tasks that need tracking.
This way, conversations stay organized, visible to the community, and future contributors can benefit from past discussions.