scene_pymujoco

Scene utilities for interactive Python MuJoCo simulations.

This module provides the mujoco_scene helper used by RobotBlockSet MuJoCo backends to load models, manage the passive viewer, render auxiliary camera windows, and control simulation stepping and resets.

class robotblockset.mujoco.scene_pymujoco.mujoco_scene(model_xml_file: str | None = None, model: mujoco.MjModel | None = None, show_camera: List[str | int] | None = None, synchronized: bool = True, verbose: int = 0)[source]

Bases: rbs_object

MuJoCo scene manager with viewer and optional camera-window support.

Attributes:

  • spec (Optional[mujoco.MjSpec]) – MuJoCo specification object when the scene was loaded from XML.

  • model (mujoco.MjModel) – Compiled MuJoCo model used by the scene.

  • data (mujoco.MjData) – Runtime MuJoCo data associated with model.

  • pause (bool) – Flag indicating whether simulation stepping is paused.

  • synchronized (bool) – Whether simulation stepping is synchronized to the model timestep.

  • viewer (Optional[mujoco.viewer.Handle]) – Passive MuJoCo viewer used for the main scene window.

  • show_camera (list[Union[str, int]]) – Camera names or IDs rendered in additional windows.

  • visual_thread (threading.Thread) – Background thread that owns the viewer loop.

Create a MuJoCo scene manager.

Parameters:

  • model_xml_file (str, optional) – Path to the MuJoCo XML model file to load.

  • model (mujoco.MjModel, optional) – Existing MuJoCo model to use instead of loading from XML.

  • show_camera (Optional[List[Union[str, int]]], optional) – Camera names or IDs to render in auxiliary windows.

  • synchronized (bool, optional) – If True, synchronize stepping to the MuJoCo model timestep.

  • verbose (int, optional) – Verbosity level used for status messages.

Returns:

This constructor initializes the MuJoCo scene object in place.

Return type:

None

__init__(model_xml_file: str | None = None, model: mujoco.MjModel | None = None, show_camera: List[str | int] | None = None, synchronized: bool = True, verbose: int = 0) → None[source]

Create a MuJoCo scene manager.

Parameters:

  • model_xml_file (str, optional) – Path to the MuJoCo XML model file to load.

  • model (mujoco.MjModel, optional) – Existing MuJoCo model to use instead of loading from XML.

  • show_camera (Optional[List[Union[str, int]]], optional) – Camera names or IDs to render in auxiliary windows.

  • synchronized (bool, optional) – If True, synchronize stepping to the MuJoCo model timestep.

  • verbose (int, optional) – Verbosity level used for status messages.

Returns:

This constructor initializes the MuJoCo scene object in place.

Return type:

None

start_simulation() → None[source]

Start the visualization thread if it is not already running.

Returns:

This method launches the background render loop.

Return type:

None

stop_simulation() → None[source]

Stop the visualization thread and close viewer windows.

Returns:

This method stops the background render loop.

Return type:

None

restart_simulation() → None[source]

Restart the viewer thread and recompile the model when possible.

Returns:

This method restarts visualization using the current scene state.

Return type:

None

render() → None[source]

Renders the simulation and the camera windows (if specified).

Runs the simulation and handles rendering for the main viewer and any additional camera windows. Also handles input events, stepping the simulation, and updating the viewer’s state.

Return type:

None

mj_pause() → None[source]

Pause simulation stepping.

Returns:

This method sets the internal pause flag.

Return type:

None

mj_run() → None[source]

Resume simulation stepping.

Returns:

This method clears the internal pause flag.

Return type:

None

mj_wait(wait: float = 0) → None[source]

Wait for a specified duration.

Parameters:

wait (float, optional) – Amount of simulated time (in seconds) to advance.

Returns:

This method blocks until the requested amount of simulated time has elapsed.

Return type:

None

mj_reset(keyframe: int | None = None) → None[source]

Resets the simulation state to its initial state, or to a specified keyframe.

Parameters:

keyframe (int, optional) – The index of the keyframe to reset to. If None, the simulation is reset to the initial state.

Return type:

None

mj_capture_camera(camera: int | str = -1, scene_option: mujoco.MjvOption | None = None, **kwargs: object) → ndarray[source]

Captures an image from a specified camera in the simulation.

Parameters:

  • camera (Union[int, str], optional) – The ID or name of the camera to capture. Default is -1, which captures the default camera.

  • scene_option (mujoco.MjvOption, optional) – Rendering options to customize the scene appearance. Default is None.

  • **kwargs (object) – Additional keyword arguments passed to mujoco.Renderer.

Returns:

The rendered image as a NumPy array (RGB format).

Return type:

np.ndarray

Classes

mujoco_scene([model_xml_file, model, ...])

MuJoCo scene manager with viewer and optional camera-window support.