Introduction to MuJoCo

MuJoCo is a free and open-source physics engine that aims to facilitate research and development in robotics, biomechanics, graphics and animation, and other areas where fast and accurate simulation is needed.

• MuJoCo stands for Multi-Joint dynamics with Contact
• It is a (rigid-body) simulator
• In my personal opinion, a (proper) simulator consists of:
  • Rigid-body simulation by solving an equation of motion (e.g., an articulated body algorithm)
  • Contact solver (main cause of sim-to-real gap)
  • Easy-to-use visualizer (VERY IMPORTANT for conducting research)

Topics Covered in This Tutorial

1. Introduction to MuJoCo and our lab-maintained mujoco_parser
2. Forward Kinematics
3. Forward Dynamics
4. Inverse Kinematics
5. Inverse Dynamics
6. Planning using RRT
7. Vision Reasoning using GPT4o and open-vocab detection
8. Motion Retargeting of Unitree G1
9. PID Control of Snapbot
10. Reinforcement Learning using Soft Actor-Critic of Snapbot

Enjoy!

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Contact

Sungjoon sungjoon dash choi at korea dot ac dot kr