blenderproc.python.types.LinkUtility module

class blenderproc.python.types.LinkUtility.Link(bpy_object)

Bases: blenderproc.python.types.EntityUtility.Entity

_clip_value_from_constraint(bone, value=0, constraint_name='', axis='X')

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.

_create_ik_bone_controller(relative_location=[0.0, 0.0, 0.0], use_rotation=True, chain_length=0)

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

Parameters:

• relative_location (Union[List[float], Vector]) – 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 – Whether to rotate the child links as well. Defaults to True.
• chain_length – The number of parent links which are influenced by this ik bone. Defaults to 0 for all parents.

Return type:

(<class ‘bpy_types.PoseBone’>, <class ‘bpy_types.PoseBone’>, <class ‘Matrix’>)

Returns:

Constraint and control bone.

_determine_rotation_axis(bone)

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')

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')

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.

get_all_objs()

Returns all meshes of this link.

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

get_child()

Returns this link’s child.

Return type:Link Returns:Child link.

get_collision_local2world_mats()

Returns the transformation matrices from world to the collision parts.

Return type:Optional[List] Returns:List of transformation matrices.

get_collisions()

Returns the collision meshes for this link.

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

get_fk_ik_mode()

Returns the currently selected mode.

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

get_inertial()

Returns the inertial meshes for this link.

Return type:Inertial Returns:List of inertial meshes.

get_inertial_local2world_mat()

Returns the transformation matrix from world to the inertial part.

Return type:Matrix Returns:The transformation matrix.

get_joint_rotation(frame=None)

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()

Returns the joint type.

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

get_parent()

Returns this link’s parent.

Return type:Link Returns:Parent link.

get_visual_local2world_mats()

Returns the transformation matrices from world to the visual parts.

Return type:Optional[List] Returns:List of transformation matrices.

get_visuals()

Returns the visual meshes for this link.

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

hide(hide_object=True)

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.

parent_with_bone(weight_distribution='rigid')

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)

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

Parameters:armature (Armature) – The armature.

set_bone(bone)

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

Parameters:bone (PoseBone) – The bone.

set_child(child)

Sets the child of this link.

Parameters:child (Link) – Child link.

set_collision_local2link_mats(matrix_list)

Sets the transformation matrices from link to the collision parts.

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

set_collisions(collisions)

Sets the collision meshes for this link.

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

set_fk_bone(bone)

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

Parameters:bone (PoseBone) – The bone.

set_ik_bone(bone)

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

Parameters:bone (PoseBone) – The bone.

set_ik_bone_constraint(bone)

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

Parameters:bone (PoseBone) – The bone.

set_ik_bone_controller(bone)

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

Parameters:bone (PoseBone) – The bone.

set_inertial(inertial)

Sets the inertial meshes for this link.

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

set_inertial_local2link_mat(matrix)

Sets the transformation matrix from link to inertial.

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

set_joint_type(joint_type)

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)

Sets the transformation matrix from bone to link.

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

set_location(*args, **kwargs)

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)

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

Parameters:location (Union[List[float], <built-in function array>, Vector]) – Location vector.

set_parent(parent)

Sets the parent of this link.

Parameters:parent (Link) – Parent link.

set_rotation_euler(*args, **kwargs)

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)

Sets the rotation for this link in forward kinematics mode. See self._set_rotation_euler() for details.

set_rotation_euler_ik(*args, **kwargs)

Sets the rotation for this link in inverse kinematics mode. See self._set_rotation_euler() for details.

set_visual_local2link_mats(matrix_list)

Sets the transformation matrices from link to the visual parts.

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

set_visuals(visuals)

Sets the visual meshes for this link.

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

switch_fk_ik_mode(mode='fk', keep_pose=True)

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