Method _reload_from_data

dm_control/mujoco/engine.py:392–430

Initializes a new or existing `Physics` instance from a `wrapper.MjData`. Assigns all attributes, sets up named indexing, and creates rendering contexts if rendering is enabled. The default constructor as well as the other `reload_from` methods should delegate to this method.

(self, data)

    self._reload_from_data(data)

  def _reload_from_data(self, data):
    """Initializes a new or existing `Physics` instance from a `wrapper.MjData`.

    Assigns all attributes, sets up named indexing, and creates rendering
    contexts if rendering is enabled.

    The default constructor as well as the other `reload_from` methods should
    delegate to this method.

    Args:
      data: Instance of `wrapper.MjData`.
    """
    if not isinstance(data, wrapper.MjData):
      raise TypeError(f'Expected wrapper.MjData. Got: {type(data)}.')
    self._data = data

    # Performance optimization: pre-allocate numpy arrays used when checking for
    # MuJoCo warnings on each step.
    self._warnings = self.data.warning.number
    self._warnings_before = np.empty_like(self._warnings)
    self._new_warnings = np.empty(dtype=bool, shape=(len(self._warnings),))

    # Forcibly free any previous GL context in order to avoid problems with GL
    # implementations that do not support multiple contexts on a given device.
    with self._contexts_lock:
      if self._contexts:
        self._free_rendering_contexts()

    # Call kinematics update to enable rendering.
    try:
      self.after_reset()
    except _control.PhysicsError as e:
      logging.warning(e)

    # Set up named indexing.
    axis_indexers = index.make_axis_indexers(self.model)
    self._named = NamedIndexStructs(
        model=index.struct_indexer(self.model, 'mjmodel', axis_indexers),
        data=index.struct_indexer(self.data, 'mjdata', axis_indexers),)

  def free(self):
    """Frees the native MuJoCo data structures held by this `Physics` instance.