blenderproc.python.loader.BopLoader module

Provides functions to load the objects inside the bop dataset.

class blenderproc.python.loader.BopLoader._BopLoader

Bases: object

CACHED_OBJECTS = {}

static compute_camera_to_world_trafo(cam_H_m2w_ref, cam_H_m2c_ref, source_frame)

Returns camera to world transformation in blender coords.

Parameters:

• cam_H_m2c_ref (array) – (4x4) Homog trafo from object to camera coords.

• cam_H_m2w_ref (array) – (4x4) Homog trafo from object to world coords.

• source_frame (List[str]) – Can be used if the given positions and rotations are specified in frames different from the blender frame.

Return type:

ndarray

Returns:

cam_H_c2w: (4x4) Homog trafo from camera to world coords.

static get_loaded_obj(model_path)

Returns the object if it has already been loaded.

Parameters:

model_path (str) – Model path of the new object.

Return type:

Optional[Object]

Returns:

Object if found, else return None.

static get_ref_cam_extrinsics_intrinsics(sc_camera, cam_id, insts, scale)

Get camK and transformation from object instance 0 to camera cam_id as reference.

Parameters:

• sc_camera (dict) – BOP scene_camera file.

• cam_id (int) – BOP camera id.

• insts (dict) – Instance from BOP scene_gt file.

• scale (float) – Factor to transform get pose in mm or meters.

Return (camK, cam_H_m2c_ref):

loaded camera matrix. Loaded object to camera transformation.

Return type:

Tuple[ndarray, ndarray]

static insert_key_frames(obj, frame_id)

Insert key frames for given object pose.

Parameters:

• obj (Object) – Loaded object.

• frame_id (int) – The frame number where key frames should be inserted.

static load_mesh(obj_id, model_p, bop_dataset_name, scale=1)

Loads BOP mesh and sets category_id.

Parameters:

• obj_id (int) – The obj_id of the BOP Object.

• model_p (dict) – model parameters defined in dataset_params.py in bop_toolkit.

• bop_dataset_name (str) – The name of the used bop dataset.

• scale (float) – factor to transform set pose in mm or meters.

Return type:

MeshObject

Returns:

Loaded mesh object.

static set_object_pose(cur_obj, inst, scale)

Set object pose for current obj

Parameters:

• cur_obj (Object) – Current object.

• inst (dict) – instance from BOP scene_gt file.

• scale (float) – factor to transform set pose in mm or meters.

static setup_bop_toolkit(bop_dataset_path)

Install the bop_toolkit from Github and set an environment variable pointing to the BOP datasets

Parameters:

bop_dataset_path (str) – Path to the bop dataset

Return (bop_path, bop_dataset_name):

Path to BOP datasets and BOP dataset name

Return type:

Tuple[str, str]

blenderproc.python.loader.BopLoader.load_bop_intrinsics(bop_dataset_path, split='test', cam_type='')

Load and set the camera matrix and image resolution of a specified BOP dataset

Parameters:

• bop_dataset_path (str) – Full path to a specific bop dataset e.g. /home/user/bop/tless.

• split (str) – Optionally, train, test or val split depending on BOP dataset, defaults to “test”

• cam_type (str) – Camera type. If not defined, dataset-specific default camera type is used.

Return type:

Tuple[ndarray, int, int]

Returns:

camera matrix K, W, H

blenderproc.python.loader.BopLoader.load_bop_objs(bop_dataset_path, model_type='', obj_ids=None, sample_objects=False, num_of_objs_to_sample=None, obj_instances_limit=-1, mm2m=None, object_model_unit='m', move_origin_to_x_y_plane=False)

Loads all or a subset of 3D models of any BOP dataset

Parameters:

• bop_dataset_path (str) – Full path to a specific bop dataset e.g. /home/user/bop/tless.

• model_type (str) – Optionally, specify type of BOP model. Available: [reconst, cad or eval].

• obj_ids (Optional[List[int]]) – List of object ids to load. Default: [] (load all objects from the given BOP dataset)

• sample_objects (bool) – Toggles object sampling from the specified dataset.

• num_of_objs_to_sample (Optional[int]) – 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.

• obj_instances_limit (int) – Limits the amount of object copies when sampling. Default: -1 (no limit).

• mm2m (Optional[bool]) – Specify whether to convert poses and models to meters (deprecated).

• object_model_unit (str) – The unit the object model is in. Object model will be scaled to meters. This does not affect the annotation units. Available: [‘m’, ‘dm’, ‘cm’, ‘mm’].

• move_origin_to_x_y_plane (bool) – 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.

Return type:

List[MeshObject]

Returns:

The list of loaded mesh objects.

blenderproc.python.loader.BopLoader.load_bop_scene(bop_dataset_path, scene_id, model_type='', cam_type='', split='test', source_frame=None, mm2m=None, object_model_unit='m')

Replicate a BOP scene from the given dataset: load scene objects, object poses, camera intrinsics and

extrinsics

• 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

Parameters:

• bop_dataset_path (str) – Full path to a specific bop dataset e.g. /home/user/bop/tless.

• scene_id (int) – Specify BOP dataset scene to synthetically replicate. Default: -1 (no scene is replicated, only BOP Objects are loaded).

• model_type (str) – Optionally, specify type of BOP model. Available: [reconst, cad or eval].

• cam_type (str) – Camera type. If not defined, dataset-specific default camera type is used.

• split (str) – Optionally, test or val split depending on BOP dataset.

• source_frame (Optional[List[str]]) – 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). Default: [“X”, “-Y”, “-Z”], Available: [‘X’, ‘Y’, ‘Z’, ‘-X’, ‘-Y’, ‘-Z’].

• mm2m (Optional[bool]) – Specify whether to convert poses and models to meters (deprecated).

• object_model_unit (str) – The unit the object model is in. Object model will be scaled to meters. This does not affect the annotation units. Available: [‘m’, ‘dm’, ‘cm’, ‘mm’].

Return type:

List[MeshObject]

Returns:

The list of loaded mesh objects.