Orbital Simulator

A fast N-body orbital mechanics simulator written in Rust.
Simulate the motion of celestial bodies under Newtonian gravity, with easy configuration and efficient output for visualization.

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Features

• N-body simulation
• Configurable initial conditions via JSON
• Binary trajectory files
• Progress bar
• Unit normalization
• Ready for visualization (Coming Soon)

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Getting Started

Prerequisites

• Rust (edition 2021 or later)
• Bevy dependencies (for 3D visualization; see Bevy's docs for Linux requirements)

Build

cargo build --release

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Running the Simulator (CLI)

cargo run --release --bin simulator -- \
  --config path/to/your_config.json \
  --time 30d \
  --step-size 10.0 \
  --output-file trajectory.bin

Arguments:

• --config (required): Path to your JSON config file with initial body states.
• --time (required): Total simulation time (e.g. 10s, 5m, 2h, 100d).
• --step-size: Simulation step size in seconds (default: 10.0).
• --output-file (required): Where to save the trajectory data.
• --steps-per-save: How often to update the progress bar and save (default: 1000).

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Running the 3D Visualizer (orbiter)

cargo run --release --bin orbiter

• Opens a 3D window with a camera and a blue sphere (placeholder for future simulation data).
• Camera controls:
  • Right mouse drag: Orbit around the origin
  • Scroll wheel: Zoom in/out

Future updates will allow loading and animating simulation output.

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Configuration

The config file is a JSON file describing the initial state of each body.
Examples provided in config/

{
  "bodies": [
    {
      "name": "BodyName",
      "mass": 1e10, //kg
      "position": [0.0, 0.0, 0.0], //meters
      "velocity": [0.0, 0.0, 0.0] // m/s
    },
    ...
  ]
}

• Units:
  • Mass: kilograms (kg)
  • Position: meters (m)
  • Velocity: meters per second (m/s)

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Output

• The simulator writes binary snapshots of the system state to the output file using bincode.
• Each snapshot contains the simulation time and the real (de-normalized) positions, velocities, and masses of all bodies.

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Extending

• Add more bodies or change initial conditions in the config file.
• Adjust step size and simulation time for accuracy/performance trade-offs.
• The code is modular and ready for extension (e.g., new force laws, output formats, or integrators).

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License

MIT License

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Acknowledgments

• Rust
• Bevy for 3D visualization
• glam for fast vector math
• clap for CLI parsing
• indicatif for progress bars
• serde and bincode for serialization

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Author

• Thomas Faour