MuJoCo Visualizer

MuJoCo Visualizer#

JAXsim provides a simple interface with MuJoCo’s visualizer. The visualizer is a separate process that communicates with the main simulation process. This allows for the simulation to run at full speed while the visualizer can run at a different frame rate.

Loaders#

class jaxsim.mujoco.loaders.ModelToMjcf[source]#

Class to convert a URDF/SDF file or a ROD model to a Mujoco MJCF string.

static convert(model, considered_joints=None, plane_normal=(0, 0, 1), heightmap=None, heightmap_samples_xy=(101, 101), cameras=())[source]#

Convert a model to a Mujoco MJCF string.

Parameters:

model (str | Path | Model) – The URDF/SDF file or ROD model to convert.
considered_joints (list[str] | None) – The list of joint names to consider in the conversion.
plane_normal (tuple[float, float, float]) – The normal vector of the plane.
heightmap (bool | None) – Whether to generate a heightmap.
heightmap_samples_xy (tuple[int, int]) – The number of points in the heightmap grid.
cameras (MujocoCamera | Sequence[MujocoCamera] | dict[str, str] | Sequence[dict[str, str]]) – The custom cameras to add to the scene.

Return type:

tuple[str, dict[str, Any]]

Returns:

A tuple containing the MJCF string and the dictionary of assets.

class jaxsim.mujoco.loaders.RodModelToMjcf[source]#

Class to convert a ROD model to a Mujoco MJCF string.

static add_floating_joint(urdf_string, base_link_name, floating_joint_name='world_to_base')[source]#

Add a floating joint to a URDF string.

Parameters:

urdf_string (str) – The URDF string to modify.
base_link_name (str) – The name of the base link to attach the floating joint.
floating_joint_name (str) – The name of the floating joint to add.

Returns:

The modified URDF string.

Return type:

str

static assets_from_rod_model(rod_model)[source]#

Generate a dictionary of assets from a ROD model.

Parameters:: rod_model (Model) – The ROD model to extract the assets from.
Returns:: A dictionary of assets.
Return type:: dict

static convert(rod_model, considered_joints=None, plane_normal=(0, 0, 1), heightmap=None, heightmap_samples_xy=(101, 101), cameras=())[source]#

Convert a ROD model to a Mujoco MJCF string.

Parameters:

rod_model (Model) – The ROD model to convert.
considered_joints (list[str] | None) – The list of joint names to consider in the conversion.
plane_normal (tuple[float, float, float]) – The normal vector of the plane.
heightmap (bool | None) – Whether to generate a heightmap.
heightmap_samples_xy (tuple[int, int]) – The number of points in the heightmap grid.
cameras (MujocoCamera | Sequence[MujocoCamera] | dict[str, str] | Sequence[dict[str, str]]) – The custom cameras to add to the scene.

Return type:

tuple[str, dict[str, Any]]

Returns:

A tuple containing the MJCF string and the dictionary of assets.

class jaxsim.mujoco.loaders.SdfToMjcf[source]#

Class to convert a SDF file to a Mujoco MJCF string.

static convert(sdf, considered_joints=None, model_name=None, plane_normal=(0, 0, 1), heightmap=None, cameras=())[source]#

Convert a SDF file to a Mujoco MJCF string.

Parameters:

sdf (str | Path) – The SDF file to convert.
considered_joints (list[str] | None) – The list of joint names to consider in the conversion.
model_name (str | None) – The name of the model to convert.
plane_normal (tuple[float, float, float]) – The normal vector of the plane.
heightmap (bool | None) – Whether to generate a heightmap.
cameras (MujocoCamera | Sequence[MujocoCamera] | dict[str, str] | Sequence[dict[str, str]]) – The list of cameras to add to the scene.

Returns:

A tuple containing the MJCF string and the assets dictionary.

Return type:

tuple

class jaxsim.mujoco.loaders.UrdfToMjcf[source]#

Class to convert a URDF file to a Mujoco MJCF string.

static convert(urdf, considered_joints=None, model_name=None, plane_normal=(0, 0, 1), heightmap=None, cameras=())[source]#

Convert a URDF file to a Mujoco MJCF string.

Parameters:

urdf (str | Path) – The URDF file to convert.
considered_joints (list[str] | None) – The list of joint names to consider in the conversion.
model_name (str | None) – The name of the model to convert.
plane_normal (tuple[float, float, float]) – The normal vector of the plane.
heightmap (bool | None) – Whether to generate a heightmap.
cameras (MujocoCamera | Sequence[MujocoCamera] | dict[str, str] | Sequence[dict[str, str]]) – The list of cameras to add to the scene.

Returns:

A tuple containing the MJCF string and the assets dictionary.

Return type:

tuple

jaxsim.mujoco.loaders.load_rod_model(model_description, is_urdf=None, model_name=None)[source]#

Load a ROD model from a URDF/SDF file or a ROD model.

Parameters:

model_description (str | Path | Model) – The URDF/SDF file or ROD model to load.
is_urdf (bool | None) – Whether to force parsing the model description as a URDF file.
model_name (str | None) – The name of the model to load from the resource.

Returns:

The loaded ROD model.

Return type:

rod.Model

Model#

class jaxsim.mujoco.model.MujocoModelHelper(model, data=None)[source]#

Helper class to create and interact with Mujoco models and data objects.

Parameters:

model (mj.MjModel)
data (mj.MjData | None)

base_link()[source]#

Return the name of the base link.

Return type:: str

base_orientation(dcm=False)[source]#

Return the orientation of the base link.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]
Parameters:: dcm (bool)

base_position()[source]#

Return the 3D position of the base link.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]

body_names()[source]#

Return the names of the bodies in the model.

Return type:: list[str]

body_orientation(body_name, dcm=False)[source]#

Return the orientation of a body.

Return type:

ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]

Parameters:

body_name (str)
dcm (bool)

body_position(body_name)[source]#

Return the position of a body.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]
Parameters:: body_name (str)

static build_from_xml(mjcf_description, assets=None, heightmap=None, heightmap_name='terrain', heightmap_radius_xy=(1.0, 1.0))[source]#

Build a Mujoco model from an MJCF description.

Parameters:

mjcf_description (str | Path) – A string containing the XML description of the Mujoco model or a path to a file containing the XML description.
assets (dict[str, Any] | None) – An optional dictionary containing the assets of the model.
heightmap (Callable[[Union[float, Array, ndarray, bool, number, bool, int, complex], Union[float, Array, ndarray, bool, number, bool, int, complex]], Union[float, Array, ndarray, bool, number, bool, int, complex]] | None) – A function in two variables that returns the height of a terrain in the specified coordinate point.
heightmap_name (str) – The default name of the heightmap in the MJCF description to load the corresponding configuration.
heightmap_radius_xy (tuple[float, float]) – The extension of the heightmap in the x-y surface corresponding to the plane over which the grid of the sampled heightmap is generated.

Return type:

MujocoModelHelper

Returns:

A MujocoModelHelper object.

geometry_names()[source]#

Return the names of the geometries in the model.

Return type:: list[str]

geometry_orientation(geometry_name, dcm=False)[source]#

Return the orientation of a geometry.

Return type:

ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]

Parameters:

geometry_name (str)
dcm (bool)

geometry_position(geometry_name)[source]#

Return the position of a geometry.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]
Parameters:: geometry_name (str)

gravity()[source]#

Return the 3D gravity vector.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]

is_fixed_base()[source]#

Return true if the model is fixed-base.

Return type:: bool

is_floating_base()[source]#

Return true if the model is floating-base.

Return type:: bool

joint_dofs(joint_name)[source]#

Return the number of DoFs of a joint.

Return type:: int
Parameters:: joint_name (str)

joint_names()[source]#

Return the names of the joints in the model.

Return type:: list[str]

joint_position(joint_name)[source]#

Return the position of a joint.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]
Parameters:: joint_name (str)

joint_positions(joint_names=None)[source]#

Return the positions of the joints.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]
Parameters:: joint_names (list[str] | None)

number_of_bodies()[source]#

Return the number of bodies in the model.

Return type:: int

number_of_dofs()[source]#

Return the number of DoFs in the model.

Return type:: int

number_of_geometries()[source]#

Return the number of geometries in the model.

Return type:: int

number_of_joints()[source]#

Return the number of joints in the model.

Return type:: int

set_base_orientation(orientation, dcm=False)[source]#

Set the 3D position of the base link.

Return type:

None

Parameters:

orientation (ndarray[tuple[int, ...], dtype[_ScalarType_co]])
dcm (bool)

set_base_position(position)[source]#

Set the 3D position of the base link.

Return type:: None
Parameters:: position (ndarray[tuple[int, ...], dtype[_ScalarType_co]])

set_joint_position(joint_name, position)[source]#

Set the position of a joint.

Return type:

None

Parameters:

joint_name (str)
position (ndarray[tuple[int, ...], dtype[_ScalarType_co]] | float)

set_joint_positions(joint_names, positions)[source]#

Set the positions of multiple joints.

Return type:

None

Parameters:

joint_names (Sequence[str])
positions (ndarray[tuple[int, ...], dtype[_ScalarType_co]] | list[ndarray[tuple[int, ...], dtype[_ScalarType_co]]])

time()[source]#

Return the simulation time.

Return type:: float

timestep()[source]#

Return the simulation timestep.

Return type:: float

jaxsim.mujoco.model.generate_hfield(heightmap, samples_xy=(11, 11), radius_xy=(1.0, 1.0))[source]#

Generate an array with elevation points sampled from a heightmap function.

The map will have the following format: ` heightmap[0, 0] heightmap[0, 1] ... heightmap[0, size[1]-1] heightmap[1, 0] heightmap[1, 1] ... heightmap[1, size[1]-1] ... heightmap[size[0]-1, 0] heightmap[size[0]-1, 1] ... heightmap[size[0]-1, size[1]-1] `

Parameters:

heightmap (Callable[[Union[float, Array, ndarray, bool, number, bool, int, complex], Union[float, Array, ndarray, bool, number, bool, int, complex]], Union[float, Array, ndarray, bool, number, bool, int, complex]]) – A function that takes two arguments (x, y) and returns the height at that point.
samples_xy (tuple[int, int]) – A tuple of two integers representing the size of the grid.
radius_xy (tuple[float, float]) – A tuple of two floats representing extension of the heightmap in the x-y surface corresponding to the area over which the grid of the sampled heightmap is generated.

Return type:

ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]

Returns:

A flat array of the sampled terrain heightmap.

Visualizer#

class jaxsim.mujoco.visualizer.MujocoVideoRecorder(model, data, fps=30, width=None, height=None, **kwargs)[source]#

Video recorder for the MuJoCo passive viewer.

Parameters:

model (MjModel)
data (MjData)
fps (int)
width (int | None)
height (int | None)

static compute_down_sampling(original_fps, target_min_fps)[source]#

Return the integer down-sampling factor to reach at least the target fps.

Parameters:

original_fps (int) – The original fps.
target_min_fps (int) – The target minimum fps.

Return type:

int

Returns:

The down-sampling factor.

record_frame(camera_name='track')[source]#

Store a frame in the buffer.

Return type:: None
Parameters:: camera_name (str)

render_frame(camera_name='track')[source]#

Render a frame.

Return type:: ndarray[tuple[int, ...], dtype[TypeVar(_ScalarType_co, bound= generic, covariant=True)]]
Parameters:: camera_name (str)

reset(model=None, data=None)[source]#

Reset the model and data.

Return type:

None

Parameters:

model (MjModel | None)
data (list[MjData] | MjData | None)

write_video(path, exist_ok=False)[source]#

Write the video to a file.

Return type:

None

Parameters:

path (Path)
exist_ok (bool)

class jaxsim.mujoco.visualizer.MujocoVisualizer(model=None, data=None)[source]#

Visualizer for the MuJoCo passive viewer.

Parameters:

model (MjModel | None)
data (MjData | None)

open(model=None, data=None, *, show_left_ui=False, close_on_exit=True, lookat=None, distance=None, azimuth=None, elevation=None)[source]#

Context manager to open the Mujoco passive viewer. :rtype: AbstractContextManager[Handle]

Note

Refer to the Mujoco documentation for details of the camera options: https://mujoco.readthedocs.io/en/stable/XMLreference.html#visual-global

Parameters:

model (MjModel | None)
data (MjData | None)
show_left_ui (bool)
close_on_exit (bool)
lookat (Sequence[float | int] | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)
distance (float | int | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)
azimuth (float | int | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)
elevation (float | int | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)

Return type:

AbstractContextManager[Handle]

open_viewer(model=None, data=None, show_left_ui=False)[source]#

Open a viewer.

Return type:

Handle

Parameters:

model (MjModel | None)
data (MjData | None)
show_left_ui (bool)

static setup_viewer_camera(viewer, *, lookat, distance=None, azimuth=None, elevation=None)[source]#

Configure the initial viewpoint of the Mujoco passive viewer.

Note

Refer to the Mujoco documentation for details of the camera options: https://mujoco.readthedocs.io/en/stable/XMLreference.html#visual-global

Return type:

Handle

Returns:

The viewer with configured camera.

Parameters:

viewer (Handle)
lookat (Sequence[float | int] | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)
distance (float | int | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)
azimuth (float | int | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)
elevation (float | int | ndarray[tuple[int, ...], dtype[_ScalarType_co]] | None)

sync(viewer, model=None, data=None)[source]#

Update the viewer with the current model and data.

Return type:

None

Parameters:

viewer (Handle)
model (MjModel | None)
data (MjData | None)

MuJoCo Visualizer

Contents

MuJoCo Visualizer#

Loaders#

Model#

Visualizer#