def __init__(self, assets_dir=None, physics_backend='BulletPhysics', time_step=0.001, gravity=[0, 0, (- 9.8)], worker_id=0, use_visualizer=False):
    'Initialize the simulator.\n\n        Args:\n            assets_dir: The assets directory.\n            physics_backend: Name of the physics engine backend.\n            time_step: Time step of the simulation.\n            gravity: The gravity as a 3-dimensional vector.\n            worker_id: The id of the multi-threaded simulation.\n            use_visualizer: Render the simulation use the debugging visualizer\n                if True.\n        '
    self._assets_dir = os.path.abspath((assets_dir or './'))
    self._gravity = gravity
    physics_class = getattr(physics, physics_backend)
    self._physics = physics_class(time_step=time_step, use_visualizer=use_visualizer, worker_id=worker_id)
    self._num_steps = 0
Initialize the simulator.

Args:
    assets_dir: The assets directory.
    physics_backend: Name of the physics engine backend.
    time_step: Time step of the simulation.
    gravity: The gravity as a 3-dimensional vector.
    worker_id: The id of the multi-threaded simulation.
    use_visualizer: Render the simulation use the debugging visualizer
        if True.
def __init__(self, assets_dir=None, physics_backend='BulletPhysics', time_step=0.001, gravity=[0, 0, (- 9.8)], worker_id=0, use_visualizer=False):
    'Initialize the simulator.\n\n        Args:\n            assets_dir: The assets directory.\n            physics_backend: Name of the physics engine backend.\n            time_step: Time step of the simulation.\n            gravity: The gravity as a 3-dimensional vector.\n            worker_id: The id of the multi-threaded simulation.\n            use_visualizer: Render the simulation use the debugging visualizer\n                if True.\n        '
    self._assets_dir = os.path.abspath((assets_dir or './'))
    self._gravity = gravity
    physics_class = getattr(physics, physics_backend)
    self._physics = physics_class(time_step=time_step, use_visualizer=use_visualizer, worker_id=worker_id)
    self._num_steps = 0