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SG Physics 2D

SG Physics 2D is a deterministic 2D physics engine for Godot, based on fixed-point math. It's useful for online multiplayer games, especially those using rollback netcode.

A physics engine is "deterministic" if it will play out exactly the same on two different computers, if both have the exact same starting state.

Most physics engines aren't deterministic (including the builtin physics engine in Godot), or are only deterministic under certain conditions (ex. Box2D is deterministic if both computers are running the same binary, so it's not deterministic cross-platform).

And that's usually fine, because most games don't need deterministic physics!

But for some games, especially online multiplayer games using certain network synchronization techniques (like rollback and prediction), a deterministic physics engine is a requirement.

Open Source
Release status
Alpha / Beta


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Shapes and mathy looking diagrams

Getting started with SG Physics 2D and deterministic physics in Godot

An introductory tutorial for SG Physics 2D, so you can implement deterministic physics in your Godot game.

Monday, 2021-12-13 @ 9:18am Read more