Gazebo

Treat a Gazebo simulation as a contract between world, robot, sensors, transport, and time. Find the first contract that is not producing believable evidence.

Start from the actual stack

• For a new robotics app or first demo, read architect before creating worlds, launchers, or containers. Reuse its compatible reference-app selection if already made. Existing-world edits, simulator debugging, and explanations stay here.
• Confirm the installed gz release, ROS distro, ros_gz pairing, render backend, and whether the run is graphical or headless.
• Use modern Gazebo (gz). Gazebo Classic and libgazebo_ros_* tutorials are a different, end-of-life stack.
• Keep upstream compatibility tables and SDF specifications as the authority for release-sensitive package names, tags, and plugin APIs.