blenderproc.python.types.LinkUtility module

All link objects are captured in this class.

class blenderproc.python.types.LinkUtility.Link(bpy_object)[source]

Bases: Entity

Every instance of this class is a link which is usually part of an URDFObject. It can have objects attached to it, and different types of armature bones for manipulation.

_clip_value_from_constraint(bone, value=0, constraint_name='', axis='X')[source]

Checks if an axis is constraint, and clips the value to the min/max of this constraint. If the constraint: does not exist, nothing is done.

Parameters:

bone (PoseBone) – The bone from which the constraints will be determined.
value (float) – Value to be clipped.
constraint_name (str) – Name of the constraint.
axis (str) – Axis to check.

Return type:

float

Returns:

Clipped value if a constraint is set, else the initial value.

_determine_rotation_axis(bone)[source]

Determines the single rotation axis and checks if the constraints are set well to have only one axis of: freedom.

Parameters:: bone (PoseBone) – Bone of which the rotation axis will be determined.
Return type:: Optional[str]
Returns:: The single rotation axis (‘X’, ‘Y’ or ‘Z’) or None if no constraint is set..

_set_fk_ik_mode(mode='fk')[source]

Sets the mode of the link.

Parameters:: mode – One of [“fk”, “ik”] denoting forward or inverse kinematics mode.

_set_rotation_euler(bone, rotation_euler, mode='absolute')[source]

Rotates the bone based on euler angles. Validates values with given constraints.

Parameters:

bone (PoseBone) – The bone to be rotated.
rotation_euler (Union[float, List[float], Euler, ndarray]) – The amount of rotation (in radians). Either three floats for x, y and z axes, or a single float. In the latter case, the axis of rotation is derived based on the rotation constraint. If these are not properly set (i.e., two axes must have equal min/max values) an exception will be thrown.
mode (str) – One of [“absolute”, “relative”]. For absolute rotations we clip the rotation value based on the constraints. For relative we don’t - this will result in inverse motion after the constraint’s limits have been reached.

create_ik_bone_controller(relative_location=None, use_rotation=True, chain_length=0)[source]

Creates an ik bone controller and a corresponding constraint bone for the respective link.

Parameters:

relative_location (Union[List[float], Vector, None]) – Relative location of the ik bone controller w.r.t. the bone’s location. This can be used to shift the point of control further away from the end effector.
use_rotation (bool) – Whether to rotate the child links as well. Defaults to True.
chain_length (int) – The number of parent links which are influenced by this ik bone. Defaults to 0 for all parents.

Return type:

Tuple[PoseBone, PoseBone, Matrix]

Returns:

Constraint and control bone.

get_all_objs()[source]

Returns all meshes of this link.

Returns:: List of all meshes (visual, collision, inertial) for this link.

get_collision_local2world_mats(parent2world_matrix=None)[source]

Returns the transformation matrices from world to the collision parts.

Parameters:: parent2world_matrix (Optional[Matrix]) – The transformation from the link’s armature to the world frame.
Return type:: Optional[List[Matrix]]
Returns:: List of transformation matrices.

get_collisions()[source]

Returns the collision meshes for this link.

Return type:: List[MeshObject]
Returns:: List of collision meshes.

get_fk_ik_mode()[source]

Returns the currently selected mode.

Return type:: str
Returns:: One of [“fk”, “ik”] denoting forward or inverse kinematics mode.

get_inertial()[source]

Returns the inertial meshes for this link.

Return type:: Inertial
Returns:: List of inertial meshes.

get_inertial_local2world_mat(parent2world_matrix=None)[source]

Returns the transformation matrix from world to the inertial part.

Parameters:: parent2world_matrix (Optional[Matrix]) – The transformation from the link’s armature to the world frame.
Return type:: Optional[Matrix]
Returns:: The transformation matrix.

get_joint_rotation(frame=None)[source]

Get current joint rotation based on euler angles.

Parameters:: frame (Optional[int]) – The desired frame.
Return type:: float
Returns:: Current joint rotation in radians.

get_joint_type()[source]

Returns the joint type.

Return type:: Optional[str]
Returns:: The joint type of the armature.

get_link_child()[source]

Returns this link’s child.

Return type:: Link
Returns:: Child link.

get_link_parent()[source]

Returns this link’s parent.

Return type:: Link
Returns:: Parent link.

get_visual_local2world_mats(parent2world_matrix=None)[source]

Returns the transformation matrices from world to the visual parts.

Parameters:: parent2world_matrix (Optional[Matrix]) – The transformation from the link’s armature to the world frame.
Return type:: Optional[List[Matrix]]
Returns:: List of transformation matrices.

get_visuals()[source]

Returns the visual meshes for this link.

Return type:: List[MeshObject]
Returns:: List of visual meshes.

hide(hide_object=True)[source]

Sets the visibility of the object and all visual, collision and inertial parts.

Parameters:: hide_object (bool) – Determines whether the object should be hidden in rendering.

mesh_as_trimesh()[source]

Returns a trimesh.Trimesh instance of the link’s first visual object, if it exists.

Return type:: Optional[Trimesh]
Returns:: The link’s first visual object as trimesh.Trimesh if the link has one or more visuals, else None.

parent_with_bone(weight_distribution='rigid')[source]

Parents all objects of the link to the bone.

Parameters:: weight_distribution – One of [‘envelope’, ‘automatic’, ‘rigid’]. For more information please see https://docs.blender.org/manual/en/latest/animation/armatures/skinning/parenting.html.

set_armature(armature)[source]

Sets the armature which holds all the bones of all links.

Parameters:: armature (Armature) – The armature.

set_bone(bone)[source]

Sets the bone controlling the visuals / collisions / inertial of the link.

Parameters:: bone (PoseBone) – The bone.

set_collision_local2link_mats(matrix_list)[source]

Sets the transformation matrices from link to the collision parts.

Parameters:: matrix_list (List[Matrix]) – List of transformation matrices.

set_collisions(collisions)[source]

Sets the collision meshes for this link.

Parameters:: collisions (List[MeshObject]) – List of collision meshes.

set_fk_bone(bone)[source]

Sets the bone controlling the forward kinematic motion of this link.

Parameters:: bone (PoseBone) – The bone.

set_ik_bone(bone)[source]

Sets the bone controlling the inverse kinematic motion of this link.

Parameters:: bone (PoseBone) – The bone.

set_ik_bone_constraint(bone)[source]

Sets the constraint bone responsible for constraining to inverse kinematic motion.

Parameters:: bone (PoseBone) – The bone.

set_ik_bone_controller(bone)[source]

Sets the control bone controlling the inverse kinematic motion for this link.

Parameters:: bone (PoseBone) – The bone.

set_inertial(inertial)[source]

Sets the inertial meshes for this link.

Parameters:: inertial (Inertial) – List of inertial meshes.

set_inertial_local2link_mat(matrix)[source]

Sets the transformation matrix from link to inertial.

Parameters:: matrix (Matrix) – The transformation matrix from link to inertial.

set_joint_type(joint_type)[source]

Sets the joint type of the link which specifies the connection to its parent.

Parameters:: joint_type (Optional[str]) – One of [‘fixed’, ‘prismatic’, ‘revolute’, ‘continuous’, ‘planar’, ‘floating’ or None].

set_link2bone_mat(matrix)[source]

Sets the transformation matrix from bone to link.

Parameters:: matrix (Matrix) – The transformation from bone to link.

set_link_child(child)[source]

Sets the child of this link.

Parameters:: child (Link) – Child link.

set_link_parent(parent)[source]

Sets the parent of this link.

Parameters:: parent (Link) – Parent link.

set_location(*args, **kwargs)[source]

Sets the location of the entity in 3D world coordinates.

Parameters:

location – The location to set.
frame – The frame number which the value should be set to. If None is given, the current frame number is used.

set_location_ik(location)[source]

Sets the location of the ik bone controller in inverse kinematics mode.

Parameters:: location (Union[List[float], array, Vector]) – Location vector.

set_rotation_euler(*args, **kwargs)[source]

Sets the rotation of the entity in euler angles.

Parameters:

rotation_euler – The euler angles to set.
frame – The frame number which the value should be set to. If None is given, the current frame number is used.

set_rotation_euler_fk(*args, **kwargs)[source]: Sets the rotation for this link in forward kinematics mode. See self._set_rotation_euler() for details.

set_rotation_euler_ik(*args, **kwargs)[source]: Sets the rotation for this link in inverse kinematics mode. See self._set_rotation_euler() for details.

set_visual_local2link_mats(matrix_list)[source]

Sets the transformation matrices from link to the visual parts.

Parameters:: matrix_list (List[Matrix]) – List of transformation matrices.

set_visuals(visuals)[source]

Sets the visual meshes for this link.

Parameters:: visuals (List[MeshObject]) – List of visual meshes.

switch_fk_ik_mode(mode='fk', keep_pose=True)[source]

Switches between forward and inverse kinematics mode. Will do this automatically when switching between e.g.: set_rotation_euler_fk() and set_rotation_euler_ik().

Parameters:

mode (str) – One of [“fk”, “ik”] denoting forward or inverse kinematics mode.
keep_pose (bool) – If specified, will keep the pose when switching modes. Otherwise, will return to the old pose of the previously selected mode.