gs.morphs.MJCF#

class genesis.options.morphs.MJCF(*, pos: tuple | None = None, euler: tuple | None = None, quat: tuple | None = None, visualization: bool = True, collision: bool = True, requires_jac_and_IK: bool = True, is_free: bool | None = None, file: Any = '', scale: float | tuple = 1.0, decimate: bool = True, decimate_face_num: int = 500, decimate_aggressiveness: int = 2, convexify: bool | None = None, decompose_nonconvex: bool | None = None, decompose_object_error_threshold: float = 0.15, decompose_robot_error_threshold: float = inf, coacd_options: CoacdOptions | None = None, recompute_inertia: bool = False, default_armature: float | None = 0.1)[source]#

Morph loaded from a MJCF file. This morph only supports RigidEntity

Note

MJCF file always contains a ‘world’ body. Although this body is added to the kinematic tree, it is used to define the initial pose of the root link. If pos, euler, or quat is specified, it will override the root pose that was originally specified in the MJCF file.

Note

Genesis currently processes MJCF as if it describing a single entity instead of an actual scene. This means that there is a single gigantic kinematic chain comprising multiple physical kinematic chains connected together using fee joints. The definition of kinematic chain has been stretched a bit to allow us. In particular, there must be multiple root links instead of a single one. One other related limitation is global / world options defined in MJCF but must be set at the scene-level in Genesis are completely ignored at the moment, e.g. the simulation timestep, integrator or constraint solver. Building an actual scene hierarchy with multiple independent entities may be supported in the future.

Note

Collision filters defined in MJCF are considered “local”, i.e. they only apply to collision pairs for which both geometries along to that specific entity. This means that there is no way to filter out collision pairs between primitive and MJCF entity at the moment.

Parameters:

  • file (str) – The path to the file.

  • scale (float or tuple, optional) – The scaling factor for the size of the entity. If a float, it scales uniformly. If a 3-tuple, it scales along each axis. Defaults to 1.0. Note that 3-tuple scaling is only supported for gs.morphs.Mesh.

  • pos (tuple, shape (3,), optional) – The position of the entity in meters as a translational offset. Mathematically, ‘pos’ and ‘euler’ options correspond respectively to the translational and rotational part of a transform that it is (left) applied on the original pose of all floating base links in the kinematic tree indiscriminately. Defaults to (0.0, 0.0, 0.0).

  • euler (tuple, shape (3,), optional) – The euler angles of the entity in degrees as a rotational offset. This follows scipy’s extrinsic x-y-z rotation convention. See ‘pos’ option documentation for details. Defaults to (0.0, 0.0, 0.0).

  • quat (tuple, shape (4,), optional) – The quaternion (w-x-y-z convention) of the entity’s baselink. If specified, euler will be ignored. Defaults to None.

  • decimate (bool, optional) – Whether to decimate (simplify) the mesh. Defaults to True. This is only used for RigidEntity.

  • decimate_face_num (int, optional) – The number of faces to decimate to. Defaults to 500. This is only used for RigidEntity.

  • decimate_aggressiveness (int) – How hard the decimation process will try to match the target number of faces, as a integer ranging from 0 to 8. 0 is losseless. 2 preserves all features of the original geometry. 5 may significantly alters the original geometry if necessary. 8 does what needs to be done at all costs. Defaults to 5. This is only used for RigidEntity.

  • convexify (bool, optional) – Whether to convexify the entity. When convexify is True, all the meshes in the entity will each be converted to a set of convex hulls. The mesh with be decomposed into multiple convex components if a single one is not sufficient to met the desired accuracy (see ‘decompose_(robot|object)_error_threshold’ documentation). The module ‘coacd’ is used for this decomposition process. If not given, it defaults to True for RigidEntity and False for other deformable entities.

  • decompose_nonconvex (bool, optional) – This parameter is deprecated. Please use ‘convexify’ and ‘decompose_(robot|object)_error_threshold’ instead.

  • decompose_object_error_threshold (bool, optional:) – For basic rigid objects (mug, table…), skip convex decomposition if the relative difference between the volume of original mesh and its convex hull is lower than this threashold. 0.0 to enforce decomposition, float(“inf”) to disable it completely. Defaults to 0.15 (15%).

  • decompose_robot_error_threshold (bool, optional:) – For poly-articulated robots, skip convex decomposition if the relative difference between the volume of original mesh and its convex hull is lower than this threashold. 0.0 to enforce decomposition, float(“inf”) to disable it completely. Defaults to float(“inf”).

  • coacd_options (CoacdOptions, optional) – Options for configuring coacd convex decomposition. Needs to be a gs.options.CoacdOptions object.

  • visualization (bool, optional) – Whether the entity needs to be visualized. Set it to False if you need a invisible object only for collision purposes. Defaults to True. visualization and collision cannot both be False.

  • collision (bool, optional) – Whether the entity needs to be considered for collision checking. Defaults to True. visualization and collision cannot both be False.

  • requires_jac_and_IK (bool, optional) – Whether this morph, if created as RigidEntity, requires jacobian and inverse kinematics. Defaults to True.

  • default_armature (float, optional) – Default rotor inertia of the actuators. In practice it is applied to all joints regardless of whether they are actuated. None to disable. Default to 0.1.

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