def load_bop(bop_dataset_path: str, sys_paths: Union[List[str], str], temp_dir: str = None, model_type: str = "", cam_type: str = "", split: str = "test", scene_id: int = -1, obj_ids: list = [], sample_objects: bool = False, num_of_objs_to_sample: int = None, obj_instances_limit: int = -1, move_origin_to_x_y_plane: bool = False, source_frame: list = ["X", "-Y", "-Z"], mm2m: bool = False) -> List[MeshObject]:
    """ Loads the 3D models of any BOP dataset and allows replicating BOP scenes

    - Interfaces with the bob_toolkit, allows loading of train, val and test splits
    - Relative camera poses are loaded/computed with respect to a reference model
    - Sets real camera intrinsics

    :param bop_dataset_path: Full path to a specific bop dataset e.g. /home/user/bop/tless.
    :param sys_paths: System paths to append. Can be a string or a list of strings.
    :param temp_dir: A temp directory which is used for writing the temporary .ply file.
    :param model_type: Optionally, specify type of BOP model.  Available: [reconst, cad or eval].
    :param cam_type: Camera type. If not defined, dataset-specific default camera type is used.
    :param split: Optionally, test or val split depending on BOP dataset.
    :param scene_id: Optionally, specify BOP dataset scene to synthetically replicate. Default: -1 (no scene is replicated,
                     only BOP Objects are loaded).
    :param obj_ids: List of object ids to load. Default: [] (all objects from the given BOP dataset if scene_id is not
                    specified).
    :param sample_objects: Toggles object sampling from the specified dataset.
    :param num_of_objs_to_sample: Amount of objects to sample from the specified dataset. If this amount is bigger than the dataset
                                  actually contains, then all objects will be loaded.
    :param obj_instances_limit: Limits the amount of object copies when sampling. Default: -1 (no limit).
    :param move_origin_to_x_y_plane: Move center of the object to the lower side of the object, this will not work when used in combination with
                                     pose estimation tasks! This is designed for the use-case where BOP objects are used as filler objects in
                                     the background.
    :param source_frame: Can be used if the given positions and rotations are specified in frames different from the blender
                        frame. Has to be a list of three strings. Example: ['X', '-Z', 'Y']: Point (1,2,3) will be transformed
                        to (1, -3, 2). Available: ['X', 'Y', 'Z', '-X', '-Y', '-Z'].
    :param mm2m: Specify whether to convert poses and models to meters.
    :return: The list of loaded mesh objects.
    """
    # Make sure sys_paths is a list
    if not isinstance(sys_paths, list):
        sys_paths = [sys_paths]

    for sys_path in sys_paths:
        if 'bop_toolkit' in sys_path:
            sys.path.append(sys_path)

    if temp_dir is None:
        temp_dir = Utility.get_temporary_directory()

    scale = 0.001 if mm2m else 1
    bop_dataset_name = os.path.basename(bop_dataset_path)
    has_external_texture = bop_dataset_name in ["ycbv", "ruapc"]
    if obj_ids or sample_objects:
        allow_duplication = True
    else:
        allow_duplication = False

    datasets_path = os.path.dirname(bop_dataset_path)
    dataset = os.path.basename(bop_dataset_path)

    print("bob: {}, dataset_path: {}".format(bop_dataset_path, datasets_path))
    print("dataset: {}".format(dataset))

    try:
        from bop_toolkit_lib import dataset_params, inout
    except ImportError as error:
        print('ERROR: Please download the bop_toolkit package and add it to sys_paths in config!')
        print('https://github.com/thodan/bop_toolkit')
        raise error

    model_p = dataset_params.get_model_params(datasets_path, dataset, model_type=model_type if model_type else None)
    cam_p = dataset_params.get_camera_params(datasets_path, dataset, cam_type=cam_type if cam_type else None)

    try:
        split_p = dataset_params.get_split_params(datasets_path, dataset, split=split)
    except ValueError:
        raise Exception("Wrong path or {} split does not exist in {}.".format(split, dataset))

    bpy.context.scene.render.resolution_x = cam_p['im_size'][0]
    bpy.context.scene.render.resolution_y = cam_p['im_size'][1]

    loaded_objects = []

    # only load all/selected objects here, use other modules for setting poses
    # e.g. camera.CameraSampler / object.ObjectPoseSampler
    if scene_id == -1:

        # TLESS exception because images are cropped
        if bop_dataset_name in ['tless']:
            cam_p['K'][0, 2] = split_p['im_size'][0] / 2
            cam_p['K'][1, 2] = split_p['im_size'][1] / 2

        # set camera intrinsics
        CameraUtility.set_intrinsics_from_K_matrix(cam_p['K'], split_p['im_size'][0], split_p['im_size'][1])

        obj_ids = obj_ids if obj_ids else model_p['obj_ids']
        # if sampling is enabled
        if sample_objects:
            loaded_ids = {}
            loaded_amount = 0
            if obj_instances_limit != -1 and len(obj_ids) * obj_instances_limit < num_of_objs_to_sample:
                raise RuntimeError("{}'s {} split contains {} objects, {} object where requested to sample with "
                                   "an instances limit of {}. Raise the limit amount or decrease the requested "
                                   "amount of objects.".format(bop_dataset_path, split, len(obj_ids),
                                                               num_of_objs_to_sample,
                                                               obj_instances_limit))
            while loaded_amount != num_of_objs_to_sample:
                random_id = choice(obj_ids)
                if random_id not in loaded_ids.keys():
                    loaded_ids.update({random_id: 0})
                # if there is no limit or if there is one, but it is not reached for this particular object
                if obj_instances_limit == -1 or loaded_ids[random_id] < obj_instances_limit:
                    cur_obj = BopLoader._load_mesh(random_id, model_p, bop_dataset_name, has_external_texture, temp_dir, allow_duplication, scale)
                    loaded_ids[random_id] += 1
                    loaded_amount += 1
                    loaded_objects.append(cur_obj)
                else:
                    print("ID {} was loaded {} times with limit of {}. Total loaded amount {} while {} are "
                          "being requested".format(random_id, loaded_ids[random_id], obj_instances_limit,
                                                   loaded_amount, num_of_objs_to_sample))
        else:
            for obj_id in obj_ids:
                cur_obj = BopLoader._load_mesh(obj_id, model_p, bop_dataset_name, has_external_texture, temp_dir, allow_duplication, scale)
                loaded_objects.append(cur_obj)

    # replicate scene: load scene objects, object poses, camera intrinsics and camera poses
    else:
        sc_gt = inout.load_scene_gt(split_p['scene_gt_tpath'].format(**{'scene_id': scene_id}))
        sc_camera = inout.load_json(split_p['scene_camera_tpath'].format(**{'scene_id': scene_id}))
        for i, (cam_id, insts) in enumerate(sc_gt.items()):
            cam_K, cam_H_m2c_ref = BopLoader._get_ref_cam_extrinsics_intrinsics(sc_camera, cam_id, insts, scale)

            if i == 0:
                # define world = first camera
                cam_H_m2w_ref = cam_H_m2c_ref.copy()

                cur_objs = []
                # load scene objects and set their poses
                for inst in insts:
                    cur_objs.append(BopLoader._load_mesh(inst['obj_id'], model_p, bop_dataset_name, has_external_texture, temp_dir, allow_duplication, scale))
                    BopLoader.set_object_pose(cur_objs[-1], inst, scale)

            cam_H_c2w = BopLoader._compute_camera_to_world_trafo(cam_H_m2w_ref, cam_H_m2c_ref, source_frame)
            # set camera intrinsics
            CameraUtility.set_intrinsics_from_K_matrix(cam_K, split_p['im_size'][0], split_p['im_size'][1])

            # set camera extrinsics as next frame
            frame_id = CameraUtility.add_camera_pose(cam_H_c2w)

            # Add key frame for camera shift, as it changes from frame to frame in the tless replication
            cam = bpy.context.scene.camera.data
            cam.keyframe_insert(data_path='shift_x', frame=frame_id)
            cam.keyframe_insert(data_path='shift_y', frame=frame_id)

            # Copy object poses to key frame (to be sure)
            for cur_obj in cur_objs:
                BopLoader._insert_key_frames(cur_obj, frame_id)

    # move the origin of the object to the world origin and on top of the X-Y plane
    # makes it easier to place them later on, this does not change the `.location`
    # This is only useful if the BOP objects are not used in a pose estimation scenario.
    if move_origin_to_x_y_plane:
        for obj in loaded_objects:
            obj.move_origin_to_bottom_mean_point()

    return loaded_objects
    def _set_cam_intrinsics(self, cam, config):
        """ Sets camera intrinsics from a source with following priority

           1. from config function parameter if defined
           2. from custom properties of cam if set in Loader
           3. default config:
                resolution_x/y: 512
                pixel_aspect_x: 1
                clip_start:   : 0.1
                clip_end      : 1000
                fov           : 0.691111

        :param cam: The camera which contains only camera specific attributes.
        :param config: A configuration object with cam intrinsics.
        """
        if config.is_empty():
            return

        width = config.get_int("resolution_x",
                               bpy.context.scene.render.resolution_x)
        height = config.get_int("resolution_y",
                                bpy.context.scene.render.resolution_y)

        # Clipping
        clip_start = config.get_float("clip_start", cam.clip_start)
        clip_end = config.get_float("clip_end", cam.clip_end)

        if config.has_param("cam_K"):
            if config.has_param("fov"):
                print(
                    'WARNING: FOV defined in config is ignored. Mutually exclusive with cam_K'
                )
            if config.has_param("pixel_aspect_x"):
                print(
                    'WARNING: pixel_aspect_x defined in config is ignored. Mutually exclusive with cam_K'
                )

            cam_K = np.array(config.get_list("cam_K")).reshape(3, 3).astype(
                np.float32)

            CameraUtility.set_intrinsics_from_K_matrix(cam_K, width, height,
                                                       clip_start, clip_end)
        else:
            # Set FOV
            fov = config.get_float("fov", cam.angle)

            # Set Pixel Aspect Ratio
            pixel_aspect_x = config.get_float(
                "pixel_aspect_x", bpy.context.scene.render.pixel_aspect_x)
            pixel_aspect_y = config.get_float(
                "pixel_aspect_y", bpy.context.scene.render.pixel_aspect_y)

            # Set camera shift
            shift_x = config.get_float("shift_x", cam.shift_x)
            shift_y = config.get_float("shift_y", cam.shift_y)

            CameraUtility.set_intrinsics_from_blender_params(fov,
                                                             width,
                                                             height,
                                                             clip_start,
                                                             clip_end,
                                                             pixel_aspect_x,
                                                             pixel_aspect_y,
                                                             shift_x,
                                                             shift_y,
                                                             lens_unit="FOV")

        CameraUtility.set_stereo_parameters(
            config.get_string("stereo_convergence_mode",
                              cam.stereo.convergence_mode),
            config.get_float("convergence_distance",
                             cam.stereo.convergence_distance),
            config.get_float("interocular_distance",
                             cam.stereo.interocular_distance))
        if config.has_param("depth_of_field"):
            depth_of_field_config = Config(
                config.get_raw_dict("depth_of_field"))
            fstop_value = depth_of_field_config.get_float("fstop", 2.4)
            aperture_blades = depth_of_field_config.get_int(
                "aperture_blades", 0)
            aperture_ratio = depth_of_field_config.get_float(
                "aperture_ratio", 1.0)
            aperture_rotation = depth_of_field_config.get_float(
                "aperture_rotation_in_rad", 0.0)
            if depth_of_field_config.has_param(
                    "depth_of_field_dist") and depth_of_field_config.has_param(
                        "focal_object"):
                raise RuntimeError(
                    "You can only use either depth_of_field_dist or a focal_object but not both!"
                )
            if depth_of_field_config.has_param("depth_of_field_dist"):
                depth_of_field_dist = depth_of_field_config.get_float(
                    "depth_of_field_dist")
                CameraUtility.add_depth_of_field(cam, None, fstop_value,
                                                 aperture_blades,
                                                 aperture_rotation,
                                                 aperture_ratio,
                                                 depth_of_field_dist)
            elif depth_of_field_config.has_param("focal_object"):
                focal_object = depth_of_field_config.get_list("focal_object")
                if len(focal_object) != 1:
                    raise RuntimeError(
                        f"There has to be exactly one focal object, use 'random_samples: 1' or change "
                        f"the selector. Found {len(focal_object)}.")
                CameraUtility.add_depth_of_field(Entity(focal_object[0]),
                                                 fstop_value, aperture_blades,
                                                 aperture_rotation,
                                                 aperture_ratio)
            else:
                raise RuntimeError(
                    "The depth_of_field dict must contain either a focal_object definition or "
                    "a depth_of_field_dist")