Rattle is an integration project which combines a fully-featured physics engine backend into a server-side environment, allowing a game world's state (blocks, entities, etc.) to influence the physics state, and allow that physics state to be displayed to clients via vanilla packets (no client mod required).

The project currently uses the Rapier backend, a rigid-body physics library, with Java bindings via rapier-ffi's rapier-java module, and integrated in the rattle-rapier module.

This project requires Java 19, and the --enable-preview --enable-native-access=ALL-UNNAMED flags!

Features

• [x] Rigid body physics and collision detection
• [x] Integration with the world, so terrain and entities are automatically included as collision shapes
• [x] Fully server-side compatible; no client mods required
• [x] Compatible with Paper, Folia and Fabric
• [x] Free and open-source under the MIT license

Motivation

Minecraft is a game that does not have advanced 3D physics - the limits of what it can do is basically ray-tests and simple AABB collision response. However, physics simulations are really cool, and having it integrate cleanly with the world would be even more impressive.

The code is implemented as generically as possible to run on the server-side rather than the client-side, because it means that:

• all calculations happen on a single consistent environment
• clients don't need to download any mods for a mod loader (Forge, Fabric etc.) to interact with physics

There have already been projects which integrate some degree of rigid-body physics into the game, however those are mainly used for one-off specific features, and most are client-side mods. Rattle acts instead as a framework for other projects to use to integrate physics into a world.

Usage

For server admins

Download the latest unstable (snapshot) version from GitHub Actions:

• Open the ZIP
• Enter the directory for your chosen platform
• Enter build/libs/
• Extract rattle-[platform]-[version].jar into your platform's mods or plugins folder

For developers

See the version badges for the latest release and snapshot builds.

Modules:

• rattle-api - platform-independent API
• rattle-rapier - Rapier physics engine implementation
• rattle-common - common library for implementing the API onto a platform
• rattle-paper - Paper implementation
• rattle-fabric - Fabric implementation

repositories {
  mavenCentral()
  // for snapshot builds
  // maven("https://s01.oss.sonatype.org/content/repositories/snapshots/")
}

dependencies {
  implementation("io.github.aecsocket", "rapier-MODULE", "VERSION")
}