Rayon

What Rayon does Rayon is a library that adds rigid body simulation to Minecraft entities. It uses the Bullet Physics engine to calculate motion for custom entities while the game's original physics continue to run unchanged. The result is a parallel physics layer that mod developers can tap into for entities that need realistic momentum, collision response, and rotational behavior beyond what vanilla provides. ## Who it's for The mod targets developers building custom entities that require physics-driven movement. If you're making a rolling boulder, a tumbling vehicle, or any entity that should react to forces and collisions with mass and inertia, Rayon supplies the simulation backbone. Players only need to install it when a mod they use declares Rayon as a dependency. ## Verified capabilities Rayon integrates the Bullet Physics library directly into the Minecraft runtime. It runs on both client and server because the simulation must stay in sync across sides. The library exposes an API that lets other mods register custom entity types with rigid body properties such as mass, shape, and material. Vanilla entities aren't affected unless a mod explicitly opts them in. ## Compatibility and requirements Rayon supports Fabric and Forge. The Modrinth project lists Minecraft versions 1.20.1, 1.19.4, 1.19.3, 1.19.2, 1.19.1, and 1.19. Each version is declared individually; no continuous range is implied. Both client and server installations are required. The license is MIT. ## Development setup Developers add Rayon through the Lazurite Maven repository. The Gradle snippets differ between loaders: Fabric uses a modImplementation declaration while Forge uses an implementation declaration with fg.deobf. Version numbers are published on the Lazurite Maven index.