Double Pendulum Simulation

physics simulation of double pendulum system built with C++ and Qt6.

Demonstration

About

The double pendulum is a classic example of a chaotic system in physics. Small changes in initial conditions lead to vastly different outcomes over time. This project simulates the motion of two connected pendulums using Lagrangian mechanics and numerical integration.

Physics

The simulation solves the coupled differential equations of motion derived from the Lagrangian of the system:

Where:

• theta1, theta2 - angles of the first and second pendulum
• m1, m2 - masses of the pendulum bobs
• l1, l2 - lengths of the pendulum rods
• g - acceleration due to gravity

Features

• Real-time simulation at 60 FPS
• Accurate physics using Euler integration method
• Visual representation with rods and colored bobs
• Start/Stop control

Tech Stack

• C++17
• Qt6 (Widgets, Graphics View Framework)
• CMake

Building

Prerequisites

• Qt6 (6.7 or later recommended)
• CMake 3.16+
• C++17 compatible compiler

Build Steps

mkdir build && cd build
cmake ..
make
./simulation

Or open the project in Qt Creator and build from there.

License

This project is open source and available for educational purposes.