Mocari

A pure Rust Live2D/Cubism runtime experiment

Why

Live2D Cubism Core is closed source. For a long time, developers have mostly had to use native bindings to call it from languages like Rust. That approach limits portability, integration, and optimization, which is why Mocari exists. Rust is fast and reliable, making it a strong choice for rebuilding a Live2D-compatible runtime.

Goal

Mocari aims to become a practical Rust library. It should be easy to use, easy to call, and simple to integrate without complicated native runtime setup.

Install

Mocari is published on crates.io:

cargo add mocari

API documentation is hosted on docs.rs/mocari.

Build from source

You need:

• Rust
• Cargo

git clone https://github.com/Eatgrapes/Mocari.git
cd Mocari
cargo build

Renderer backends

By default Mocari builds without a renderer: it gives you parsing, the parameter/motion runtime, and a backend-agnostic render::common layer (vertices, draw-order sorting, clipping/mask layout) so you can drive any graphics API yourself.

A built-in wgpu backend is available behind a feature:

[dependencies]
mocari = { version = "0.1", features = ["wgpu"] }

To write your own backend, build on the types in mocari::render::common and feed them Moc3DrawableMesh data from the runtime.

Status

This project currently implements:

• Reading .moc3 files
• Rendering models correctly
• Rendering model motions
• Rendering model expressions
• Playing tap-triggered hit-area motions
• More Cubism runtime features

Statement

Mocari is an unofficial and independent experimental project. This project is not affiliated with, endorsed by, sponsored by, or certified by Live2D Inc. "Live2D" and "Cubism" are trademarks or registered trademarks of their respective owners. This repository does not contain Live2D Cubism Core, Live2D SDK binaries, official source code, or any proprietary files distributed by Live2D Inc. The purpose of this project is to explore a pure Rust runtime and renderer for compatible 2D model data. It is provided for educational, research, and interoperability purposes only. Users are responsible for ensuring that their use of this project complies with the licenses of Live2D Inc., model creators, asset owners, and applicable laws. If you are a rights holder and believe that any content in this repository should not be published, please contact the maintainer or open an issue, and the relevant content will be reviewed.