Research-Stack/5-Applications/text-to-cad/skills/urdf/references/validation.md

URDF Validation

Use this reference when validating generated URDF files.

Structural Checks

Validate that:

• the root element is <robot>
• the robot has a non-empty name
• every link has a unique non-empty name
• every joint has a unique non-empty name
• every joint has valid parent and child links
• parent/child links exist
• each child link has at most one parent
• the graph has exactly one root link
• the graph is connected and acyclic
• the tree has exactly links - 1 joints unless the design intentionally uses a different structure and the validator supports it

Joint Checks

Supported joint types are:

• fixed
• continuous
• revolute
• prismatic

For revolute and prismatic joints, validate lower and upper limits. Confirm axes and origins match the intended kinematic behavior.

Mesh Checks

Validate that visual mesh references:

• are non-empty
• point to supported mesh formats
• resolve from the generated URDF location or package URI convention
• refer to files that exist

If mesh references changed, confirm the corresponding CAD/STL outputs were regenerated separately.

Tooling

5-Applications/scripts/gen_urdf --summary prints a compact robot/link/joint summary after regeneration.

The URDF source reader also validates XML structure with yourdfpy, which must be installed in the active Python environment.