JSBSim GDExtension for Godot 4

This repository is a reusable Godot 4 GDExtension that integrates the JSBSim flight dynamics model.

It also contains a small demo Godot project that exercises the extension.

What’s in here

• GDExtension C++ source in src/ (class JSBGodot)
• A minimal demo project in gojb/ (open in Godot to try it)
• Submodules:
  • jsbsim/ (flight dynamics)
  • godot-cpp/ (Godot C++ bindings)

This repo intentionally does not depend on Terrain3D or large external scenery datasets.

Build

Prerequisites

• Godot 4.6+ (4.3+ is supported by the .gdextension config)
• Python 3 + SCons
• A C++ toolchain (Clang/GCC/MSVC)

Steps

1. Clone with submodules:

   git clone --recursive git@gitlab.md80.ch:gery/godotjsbsim.git
   cd godotjsbsim

2. Build JSBSim (first time only):

   cd jsbsim
   mkdir -p build && cd build
   cmake ..
   cmake --build . -j
   cd ../..

3. Build the extension:

   # macOS (Apple Silicon)
   scons arch=arm64
   
   # macOS (Apple x86)
   scons arch=x64_64
   
   # Linux
   scons 

4. Run the demo:

   cd gojb
   godot --editor

Using the plugin in your own project

The demo project contains the GDExtension config at gojb/bin/gojb.gdextension. For your own project, you typically copy (or vendor) the extension binary + .gdextension into your project and instantiate the JSBGodot node.

Note: the demo currently resolves JSBSim data from res://../jsbsim (repo layout). If you package/export a project, you’ll likely want to ship JSBSim data in a dedicated location (e.g. user:// or an unpacked folder) and point JSBSim at that path.

License

This project combines multiple open-source components:

• JSBSim: LGPL 2.1
• Godot Engine: MIT
• godot-cpp: MIT

Aircraft model

• Title: Cessna172
• Source: https://sketchfab.com/3d-models/cessna172-d1b15841c29c43d0862667300bad55a4
• Author: KOG_THORNS (https://sketchfab.com/ioai25312)