pycram.world_concepts.world_object

Module Contents

Classes

Object

Represents a spawned Object in the World.

Attributes

Link

pycram.world_concepts.world_object.Link

class pycram.world_concepts.world_object.Object(name: str, obj_type: pycram.datastructures.enums.ObjectType, path: str, description: typing_extensions.Optional[typing_extensions.Type[pycram.description.ObjectDescription]] = URDFObject, pose: typing_extensions.Optional[pycram.datastructures.pose.Pose] = None, world: typing_extensions.Optional[pycram.world.World] = None, color: typing_extensions.Optional[pycram.datastructures.dataclasses.Color] = Color(), ignore_cached_files: typing_extensions.Optional[bool] = False)

Bases: pycram.world.WorldEntity

Represents a spawned Object in the World.

The constructor loads the description file into the given World, if no World is specified the current_world will be used. It is also possible to load .obj and .stl file into the World. The rgba_color parameter is only used when loading .stl or .obj files, for URDFs set_color() can be used.

Parameters:

• name – The name of the object

• obj_type – The type of the object as an ObjectType enum.

• path – The path to the source file, if only a filename is provided then the resources directories will be searched.

• description – The ObjectDescription of the object, this contains the joints and links of the object.

• pose – The pose at which the Object should be spawned

• world – The World in which the object should be spawned, if no world is specified the current_world will be used.

• color – The rgba_color with which the object should be spawned.

• ignore_cached_files – If true the file will be spawned while ignoring cached files.

property pose

property link_names: typing_extensions.List[str]

The name of each link as a list.

Type:

return

property joint_names: typing_extensions.List[str]

The name of each joint as a list.

Type:

return

property base_origin_shift: numpy.ndarray

The shift between the base of the object and the origin of the object.

Returns:

A numpy array with the shift between the base of the object and the origin of the object.

property current_state: pycram.datastructures.dataclasses.ObjectState

Returns the current state of this entity.

Returns:

The current state of this entity.

property link_states: typing_extensions.Dict[int, pycram.datastructures.dataclasses.LinkState]

Returns the current state of all links of this object.

Returns:

A dictionary with the link id as key and the current state of the link as value.

property joint_states: typing_extensions.Dict[int, pycram.datastructures.dataclasses.JointState]

Returns the current state of all joints of this object.

Returns:

A dictionary with the joint id as key and the current state of the joint as value.

property root_link: pycram.description.ObjectDescription.Link

Returns the root link of this object.

Returns:

The root link of this object.

property root_link_name: str

Returns the name of the root link of this object.

Returns:

The name of the root link of this object.

property links_colors: typing_extensions.Dict[str, pycram.datastructures.dataclasses.Color]

The color of each link as a dictionary with link names as keys and RGBA colors as values.

prospection_world_prefix: str = 'prospection/'

The ObjectDescription of the object, this contains the name and type of the object as well as the path to the source file.

_load_object_and_get_id(path: typing_extensions.Optional[str] = None, ignore_cached_files: typing_extensions.Optional[bool] = False) → typing_extensions.Tuple[int, typing_extensions.Union[str, None]]

Loads an object to the given World with the given position and orientation. The rgba_color will only be used when an .obj or .stl file is given. If a .obj or .stl file is given, before spawning, an urdf file with the .obj or .stl as mesh will be created and this URDf file will be loaded instead. When spawning a URDf file a new file will be created in the cache directory, if there exists none. This new file will have resolved mesh file paths, meaning there will be no references to ROS packges instead there will be absolute file paths.

Parameters:

• path – The path to the description file, if None then no file will be loaded, this is useful when the PyCRAM is not responsible for loading the file but another system is.

• ignore_cached_files – Whether to ignore files in the cache directory.

Returns:

The unique id of the object and the path of the file that was loaded.

_init_joint_name_and_id_map() → None

Creates a dictionary which maps the joint names to their unique ids and vice versa.

_init_link_name_and_id_map() → None

Creates a dictionary which maps the link names to their unique ids and vice versa.

_init_links_and_update_transforms() → None

Initializes the link objects from the URDF file and creates a dictionary which maps the link names to the corresponding link objects.

_init_joints()

Initialize the joint objects from the URDF file and creates a dictionary which mas the joint names to the corresponding joint objects

_add_to_world_sync_obj_queue() → None

Adds this object to the objects queue of the WorldSync object of the World.

get_link(link_name: str) → pycram.description.ObjectDescription.Link

Returns the link object with the given name.

Parameters:

link_name – The name of the link.

Returns:

The link object.

get_link_pose(link_name: str) → pycram.datastructures.pose.Pose

Returns the pose of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The pose of the link.

get_link_position(link_name: str) → geometry_msgs.msg.Point

Returns the position of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The position of the link.

get_link_position_as_list(link_name: str) → typing_extensions.List[float]

Returns the position of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The position of the link.

get_link_orientation(link_name: str) → geometry_msgs.msg.Quaternion

Returns the orientation of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The orientation of the link.

get_link_orientation_as_list(link_name: str) → typing_extensions.List[float]

Returns the orientation of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The orientation of the link.

get_link_tf_frame(link_name: str) → str

Returns the tf frame of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The tf frame of the link.

get_link_axis_aligned_bounding_box(link_name: str) → pycram.datastructures.dataclasses.AxisAlignedBoundingBox

Returns the axis aligned bounding box of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The axis aligned bounding box of the link.

get_transform_between_links(from_link: str, to_link: str) → pycram.datastructures.pose.Transform

Returns the transform between two links.

Parameters:

• from_link – The name of the link from which the transform should be calculated.

• to_link – The name of the link to which the transform should be calculated.

get_link_color(link_name: str) → pycram.datastructures.dataclasses.Color

Returns the color of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The color of the link.

set_link_color(link_name: str, color: typing_extensions.List[float]) → None

Sets the color of the link with the given name.

Parameters:

• link_name – The name of the link.

• color – The new color of the link.

get_link_geometry(link_name: str) → typing_extensions.Union[pycram.datastructures.dataclasses.VisualShape, None]

Returns the geometry of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The geometry of the link.

get_link_transform(link_name: str) → pycram.datastructures.pose.Transform

Returns the transform of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The transform of the link.

get_link_origin(link_name: str) → pycram.datastructures.pose.Pose

Returns the origin of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The origin of the link as a ‘Pose’.

get_link_origin_transform(link_name: str) → pycram.datastructures.pose.Transform

Returns the origin transform of the link with the given name.

Parameters:

link_name – The name of the link.

Returns:

The origin transform of the link.

__repr__()

Return repr(self).

remove() → None

Removes this object from the World it currently resides in. For the object to be removed it has to be detached from all objects it is currently attached to. After this is done a call to world remove object is done to remove this Object from the simulation/world.

reset(remove_saved_states=True) → None

Resets the Object to the state it was first spawned in. All attached objects will be detached, all joints will be set to the default position of 0 and the object will be set to the position and orientation in which it was spawned.

Parameters:

remove_saved_states – If True the saved states will be removed.

attach(child_object: Object, parent_link: typing_extensions.Optional[str] = None, child_link: typing_extensions.Optional[str] = None, bidirectional: typing_extensions.Optional[bool] = True) → None

Attaches another object to this object. This is done by saving the transformation between the given link, if there is one, and the base pose of the other object. Additionally, the name of the link, to which the object is attached, will be saved. Furthermore, a simulator constraint will be created so the attachment also works while simulation. Loose attachments means that the attachment will only be one-directional. For example, if this object moves the other, attached, object will also move but not the other way around.

Parameters:

• child_object – The other object that should be attached.

• parent_link – The link name of this object.

• child_link – The link name of the other object.

• bidirectional – If the attachment should be a loose attachment.

detach(child_object: Object) → None

Detaches another object from this object. This is done by deleting the attachment from the attachments dictionary of both objects and deleting the constraint of the simulator. Afterward the detachment event of the corresponding World will be fired.

Parameters:

child_object – The object which should be detached

detach_all() → None

Detach all objects attached to this object.

update_attachment_with_object(child_object: Object)

get_position() → geometry_msgs.msg.Point

Returns the position of this Object as a list of xyz.

Returns:

The current position of this object

get_orientation() → pycram.datastructures.pose.Pose.orientation

Returns the orientation of this object as a list of xyzw, representing a quaternion.

Returns:

A list of xyzw

get_position_as_list() → typing_extensions.List[float]

Returns the position of this Object as a list of xyz.

Returns:

The current position of this object

get_base_position_as_list() → typing_extensions.List[float]

Returns the position of this Object as a list of xyz.

Returns:

The current position of this object

get_orientation_as_list() → typing_extensions.List[float]

Returns the orientation of this object as a list of xyzw, representing a quaternion.

Returns:

A list of xyzw

get_pose() → pycram.datastructures.pose.Pose

Returns the position of this object as a list of xyz. Alias for get_position().

Returns:

The current pose of this object

set_pose(pose: pycram.datastructures.pose.Pose, base: typing_extensions.Optional[bool] = False, set_attachments: typing_extensions.Optional[bool] = True) → None

Sets the Pose of the object.

Parameters:

• pose – New Pose for the object

• base – If True places the object base instead of origin at the specified position and orientation

• set_attachments – Whether to set the poses of the attached objects to this object or not.

reset_base_pose(pose: pycram.datastructures.pose.Pose)

update_pose()

Updates the current pose of this object from the world, and updates the poses of all links.

_update_all_links_poses()

Updates the poses of all links by getting them from the simulator.

move_base_to_origin_pose() → None

Move the object such that its base will be at the current origin position. This is useful when placing objects on surfaces where you want the object base in contact with the surface.

save_state(state_id) → None

Saves the state of this object by saving the state of all links and attachments.

Parameters:

state_id – The unique id of the state.

save_links_states(state_id: int) → None

Saves the state of all links of this object.

Parameters:

state_id – The unique id of the state.

save_joints_states(state_id: int) → None

Saves the state of all joints of this object.

Parameters:

state_id – The unique id of the state.

set_attachments(attachments: typing_extensions.Dict[Object, pycram.world_concepts.constraints.Attachment]) → None

Sets the attachments of this object to the given attachments. :param attachments: A dictionary with the object as key and the attachment as value.

remove_saved_states() → None

Removes all saved states of this object.

remove_links_saved_states() → None

Removes all saved states of the links of this object.

remove_joints_saved_states() → None

Removes all saved states of the joints of this object.

_set_attached_objects_poses(already_moved_objects: typing_extensions.Optional[typing_extensions.List[Object]] = None) → None

Updates the positions of all attached objects. This is done by calculating the new pose in world coordinate frame and setting the base pose of the attached objects to this new pose. After this the _set_attached_objects method of all attached objects will be called.

Parameters:

already_moved_objects – A list of Objects that were already moved, these will be excluded to prevent loops in the update.

set_position(position: typing_extensions.Union[pycram.datastructures.pose.Pose, geometry_msgs.msg.Point, typing_extensions.List], base=False) → None

Sets this Object to the given position, if base is true the bottom of the Object will be placed at the position instead of the origin in the center of the Object. The given position can either be a Pose, in this case only the position is used or a geometry_msgs.msg/Point which is the position part of a Pose.

Parameters:

• position – Target position as xyz.

• base – If the bottom of the Object should be placed or the origin in the center.

set_orientation(orientation: typing_extensions.Union[pycram.datastructures.pose.Pose, geometry_msgs.msg.Quaternion, typing_extensions.List, typing_extensions.Tuple, numpy.ndarray]) → None

Sets the orientation of the Object to the given orientation. Orientation can either be a Pose, in this case only the orientation of this pose is used or a geometry_msgs.msg/Quaternion which is the orientation of a Pose.

Parameters:

orientation – Target orientation given as a list of xyzw.

get_joint_id(name: str) → int

Returns the unique id for a joint name. As used by the world/simulator.

Parameters:

name – The joint name

Returns:

The unique id

get_root_link_description() → pycram.description.LinkDescription

Returns the root link of the URDF of this object.

Returns:

The root link as defined in the URDF of this object.

get_root_link_id() → int

Returns the unique id of the root link of this object.

Returns:

The unique id of the root link of this object.

get_link_id(link_name: str) → int

Returns a unique id for a link name.

Parameters:

link_name – The name of the link.

Returns:

The unique id of the link.

get_link_by_id(link_id: int) → pycram.description.ObjectDescription.Link

Returns the link for a given unique link id

Parameters:

link_id – The unique id of the link.

Returns:

The link object.

reset_all_joints_positions() → None

Sets the current position of all joints to 0. This is useful if the joints should be reset to their default

set_joint_positions(joint_poses: dict) → None

Sets the current position of multiple joints at once, this method should be preferred when setting multiple joints at once instead of running set_joint_position() in a loop.

Parameters:

joint_poses –

set_joint_position(joint_name: str, joint_position: float) → None

Sets the position of the given joint to the given joint pose and updates the poses of all attached objects.

Parameters:

• joint_name – The name of the joint

• joint_position – The target pose for this joint

get_joint_position(joint_name: str) → float

Parameters:

joint_name – The name of the joint

Returns:

The current position of the given joint

get_joint_damping(joint_name: str) → float

Parameters:

joint_name – The name of the joint

Returns:

The damping of the given joint

get_joint_upper_limit(joint_name: str) → float

Parameters:

joint_name – The name of the joint

Returns:

The upper limit of the given joint

get_joint_lower_limit(joint_name: str) → float

Parameters:

joint_name – The name of the joint

Returns:

The lower limit of the given joint

get_joint_axis(joint_name: str) → geometry_msgs.msg.Point

Parameters:

joint_name – The name of the joint

Returns:

The axis of the given joint

get_joint_type(joint_name: str) → pycram.datastructures.enums.JointType

Parameters:

joint_name – The name of the joint

Returns:

The type of the given joint

get_joint_limits(joint_name: str) → typing_extensions.Tuple[float, float]

Parameters:

joint_name – The name of the joint

Returns:

The lower and upper limits of the given joint

get_joint_child_link(joint_name: str) → pycram.description.ObjectDescription.Link

Parameters:

joint_name – The name of the joint

Returns:

The child link of the given joint

get_joint_parent_link(joint_name: str) → pycram.description.ObjectDescription.Link

Parameters:

joint_name – The name of the joint

Returns:

The parent link of the given joint

find_joint_above_link(link_name: str, joint_type: pycram.datastructures.enums.JointType) → str

Traverses the chain from ‘link’ to the URDF origin and returns the first joint that is of type ‘joint_type’.

Parameters:

• link_name – AbstractLink name above which the joint should be found

• joint_type – Joint type that should be searched for

Returns:

Name of the first joint which has the given type

get_positions_of_all_joints() → typing_extensions.Dict[str, float]

Returns the positions of all joints of the object as a dictionary of joint names and joint positions.

Returns:

A dictionary with all joints positions’.

update_link_transforms(transform_time: typing_extensions.Optional[rospy.Time] = None) → None

Updates the transforms of all links of this object using time ‘transform_time’ or the current ros time.

contact_points() → typing_extensions.List

Returns a list of contact points of this Object with other Objects.

Returns:

A list of all contact points with other objects

contact_points_simulated() → typing_extensions.List

Returns a list of all contact points between this Object and other Objects after stepping the simulation once.

Returns:

A list of contact points between this Object and other Objects

set_color(rgba_color: pycram.datastructures.dataclasses.Color) → None

Changes the color of this object, the color has to be given as a list of RGBA values.

Parameters:

rgba_color – The color as Color object with RGBA values between 0 and 1

get_color() → typing_extensions.Union[pycram.datastructures.dataclasses.Color, typing_extensions.Dict[str, pycram.datastructures.dataclasses.Color]]

This method returns the rgba_color of this object. The return is either:

1. A Color object with RGBA values, this is the case if the object only has one link (this

   happens for example if the object is spawned from a .obj or .stl file)

2. A dict with the link name as key and the rgba_color as value. The rgba_color is given as a Color Object.

   Please keep in mind that not every link may have a rgba_color. This is dependent on the URDF from which

   the object is spawned.

Returns:

The rgba_color as Color object with RGBA values between 0 and 1 or a dict with the link name as key and the rgba_color as value.

get_axis_aligned_bounding_box() → pycram.datastructures.dataclasses.AxisAlignedBoundingBox

Returns:

The axis aligned bounding box of this object.

get_base_origin() → pycram.datastructures.pose.Pose

Returns:

the origin of the base/bottom of this object.

copy_to_prospection() → Object

Copies this object to the prospection world.

Returns:

The copied object in the prospection world.

__copy__() → Object

Returns a copy of this object. The copy will have the same name, type, path, description, pose, world and color.

Returns:

A copy of this object.

__eq__(other)

Return self==value.

__hash__()

Return hash(self).