[isaacsim.asset.importer.mjcf] MJCF Importer

Version: 3.2.0

Core MJCF importer functionality - converts MuJoCo’s MJCF (MuJoCo XML Format) robot description files into Omniverse USD scenes. UI provided by isaacsim.asset.importer.mjcf.ui.

Enable Extension

The extension can be enabled (if not already) in one of the following ways:

Command-line interface

Define the next entry as an application argument from a terminal.

APP_SCRIPT.(sh|bat) --enable isaacsim.asset.importer.mjcf

Experience/extension configuration

Define the next entry under [dependencies] in an experience (.kit) file or an extension configuration (extension.toml) file.

[dependencies]
"isaacsim.asset.importer.mjcf" = {}

Extension Manager UI

Open the Window > Extensions menu in a running application instance and search for isaacsim.asset.importer.mjcf. Then, toggle the enable control button if it is not already active.

MJCF Importer Extension [isaacsim.asset.importer.mjcf]

MJCF Import Workflow

Use the MJCF importer configuration and converter classes to import MJCF files into USD. Below is a sample demonstrating how to import the Ant MJCF included with this extension.

import omni.usd
from isaacsim.asset.importer.mjcf import MJCFImporter, MJCFImporterConfig
from isaacsim.asset.importer.utils import stage_utils

# Get path to extension data:
ext_manager = omni.kit.app.get_app().get_extension_manager()
ext_id = ext_manager.get_enabled_extension_id("isaacsim.asset.importer.mjcf")
extension_path = ext_manager.get_extension_path(ext_id)

# setting up import configuration:
config = MJCFImporterConfig(mjcf_path=extension_path + "/data/mjcf/nv_ant.xml")

# import MJCF
importer = MJCFImporter(config)
output_path = importer.import_mjcf()

# open the resulting USD for inspection
stage = stage_utils.open_stage(output_path)

class MJCFImporter(

config: MJCFImporterConfig | None = None,

)

MuJoCo MJCF to USD importer.

Uses mujoco-usd-converter to convert MJCF files to USD format.

Parameters:

config – Optional configuration for the import operation.

Example:

>>> from isaacsim.asset.importer.mjcf import MJCFImporter
>>> MJCFImporter()
<...>

import_mjcf(

config: MJCFImporterConfig | None = None,

) → str

Import an MJCF file and convert it to USD.

Parameters:

config – Optional configuration for the import operation. If not provided, the stored importer configuration will be used.

Returns:

Path to the generated USD file.

Raises:

• ValueError – If the MJCF path is not configured.

• FileNotFoundError – If the MJCF file does not exist at the given path.

Example:

>>> from isaacsim.asset.importer.mjcf import MJCFImporter, MJCFImporterConfig

>>> importer = MJCFImporter()
>>> config = MJCFImporterConfig(mjcf_path="/tmp/robot.xml")
>>> importer.config = config
>>> # output_path = importer.import_mjcf()

property config: MJCFImporterConfig

Get the importer configuration.

Returns:

Current importer configuration.

Example:

>>> from isaacsim.asset.importer.mjcf import MJCFImporter, MJCFImporterConfig

>>> importer = MJCFImporter()
>>> importer.config  
MJCFImporterConfig(...)

class MJCFImporterConfig(

mjcf_path: str | None = None,

usd_path: str | None = None,

import_scene: bool = True,

merge_mesh: bool = False,

debug_mode: bool = False,

collision_from_visuals: bool = False,

collision_type: str = 'Convex Hull',

allow_self_collision: bool = False,

)

Configuration for MJCF import operations.

Stores settings that control how MJCF files are converted to USD.

Parameters:

• mjcf_path – Path to the MJCF (.xml) file to import.

• usd_path – Directory path where the USD file will be saved.

• import_scene – If True, imports the MJCF simulation settings along with the model.

• merge_mesh – If True, merges meshes where possible to optimize the model.

• debug_mode – If True, enables debug mode with additional logging and visualization.

• collision_from_visuals – If True, collision geometry is generated from visual geometries.

• collision_type – Type of collision geometry to use. Options: “Convex Hull”, “Convex Decomposition”, “Bounding Sphere”, “Bounding Cube”.

• allow_self_collision – If True, allows the model to collide with itself.

Example:

>>> from isaacsim.asset.importer.mjcf import MJCFImporterConfig

>>> config = MJCFImporterConfig(
...     mjcf_path="/tmp/robot.xml",
...     usd_path="/tmp/output",
...     merge_mesh=True
... )
>>> config.mjcf_path
'/tmp/robot.xml'

allow_self_collision: bool = False

collision_from_visuals: bool = False

collision_type: str = 'Convex Hull'

debug_mode: bool = False

import_scene: bool = True

merge_mesh: bool = False

mjcf_path: str | None = None

usd_path: str | None = None