Robotics Simulation Wiki — from first URDF to sim-to-real
A practical reference for robot description formats, simulation pipelines, and hardware compliance — written by an engineer who builds the conversion tools, aimed at everyone from first-year students to working roboticists.
Each article here exists because a tool on this site kept meeting the same confusion. They're short, factual, and honest about edge cases — the reference we wished existed while building the converters. No fluff, no 3,000-word intros.
The career path
- Robotics Engineer Roadmap — Zero to hired: foundations, ROS 2, the five skills in virtually every job posting, and four specialization tracks with books, courses, and milestone projects — built from real 2026 job requirements.
Start here
- Robot Simulation 101 — What actually happens inside a physics engine: the simulation loop, contacts and friction, actuators, sensors, and the reality gap.
- What is URDF? — The robot description format everything else revolves around: structure, elements, and its hard limits.
Core concepts
- What is Xacro? — Why nobody writes raw URDF for real robots — properties, macros, and how expansion works.
- Inertia in Robot Simulation — The single most common reason simulations explode: what the inertia tensor is and how to get real values.
Choosing formats
- URDF vs SDF vs MJCF vs USD — The four robot description formats compared — capabilities, tooling, and when to use which.
Reference / cheat sheets
- URDF Cheat Sheet — Every standard element and attribute on one printable page — syntax, not tutorial.
- Rotation Conventions Cheat Sheet — xyzw vs wxyz, intrinsic vs extrinsic Euler, and handedness by library — ROS, Eigen, SciPy, MuJoCo, Unity.
Shipping hardware
- EU Cyber Resilience Act, Explained — What the CRA means for small device and robotics makers — scope, classes, deadlines, and penalties, with article citations.
Learn by doing
Every concept above has a free tool to try it on immediately: validate a URDF, expand a xacro, convert to MuJoCo, or turn a CAD file into a robot model with computed inertia. Files never leave your browser.