chitin

Chitin is a compiler designed to transform various 3D geometry inputs—such as point clouds, Gaussian fields, meshes, and skinned models—into portable convex hulls suitable for physics engines. It outputs a persistent binary format (.phys) that stores quantized convex hulls, bind transforms, and collision Level of Detail (LOD) tiers, ensuring the resulting physics assets are independent of the original viewer or engine. Key capabilities include: - **Broad Input Support**: Processes PLY, OBJ, STL, GLB, and USD assets, with specific support for extracting collision geometry from Gaussian splat point clouds using opacity filtering and Poisson surface reconstruction. - **Multi-Platform Integration**: Provides thin runtime readers for Python, TypeScript, C#, and C++. It includes dedicated integrations for Three.js + Rapier (Web), Unity (via ScriptedImporter), and Unreal Engine. - **Flexible Deployment**: Offers a Python-based pipeline for heavy reconstruction and a browser-based path using WASM (via @autarkis/chitin-lite) for static meshes and Gaussian fields. - **Advanced Processing**: Features octree-based partitioning for large scenes, PCA-based flatness detection to optimize hull generation, and experimental support for per-bone convex hulls in rigged GLB models. - **Pipeline Tooling**: Includes CLI commands for extraction, inspection, and validation of .phys files, as well as a local build service with content-addressed caching.