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Use Articulated Objects

An articulated object exposes more than a rigid actor pose: tools and goals may need joint positions, limits, and machine state. Define that observation contract in your own environment module.

A practical progression is to inspect the installed button environment, whose observation entries include button state, then add a dedicated tool and goal for your mechanism. The button tutorial reuses this contract without rebuilding its articulation.

When creating your own mechanism:

  1. Load and initialize its articulation in the environment.
  2. Expose the needed joint or machine state in _get_obs_extra.
  3. Define a tool trajectory and verify the actual post-execution state.
  4. Define a stage goal using the same observation schema.
  5. Check snapshot restoration, including extra state not owned by physics.

allowed_moving_actors protects compatible entries in the saved actors mapping; do not assume it protects articulation joints. Use correct trajectories, goals, and state restoration for your mechanism.

See environments and transitions.