Gravity Simulation

A 2D gravitational n-body physics simulator written in C++.

Features

• 2D Physics: Simple Newtonian gravity simulation with position, velocity, and mass
• N-Body System: Calculate forces between multiple bodies
• CSV Output: Exports position data for analysis/plotting
• Modular Design: Separate physics engine and visualization components

Current Implementation

The simulation uses basic Euler integration with:

• Gravitational force calculation: F = G * m1 * m2 / r²
• Newton's second law: F = ma
• Position/velocity updates each timestep

Example Output: Two bodies in circular orbit around their center of mass.

Building

Requires CMake 3.20+, Clang, and GLFW.

# Configure and build
cmake --preset=default
cmake --build --preset=default

# Run physics simulation
./build/main

# Run visualization (in development)
./build/vis

Project Structure

gravsim/
├── src/
│   ├── main.cpp      # Physics simulation with CSV output
│   └── vis.cpp       # GLFW visualization (in progress)
├── CMakeLists.txt    # Build configuration
└── CMakePresets.json # Build presets

Roadmap

• GLFW Visualization: Real-time rendering of bodies and trajectories
• Collision Detection: Elastic/inelastic collisions between bodies
• Better Integration: Runge-Kutta or Verlet integration for stability
• Interactive Controls: Add/remove bodies, adjust parameters
• Performance: Spatial partitioning for large N-body simulations

Physics Notes

• Gravitational constant G = 1.0 (simplified units)
• Time step dt = 0.01 (may need adjustment for stability)
• Collision avoidance: Forces capped at minimum distance 0.01
• Current method: Euler integration (first-order, may drift over time)