# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md). # All rights reserved. # # SPDX-License-Identifier: BSD-3-Clause """ Utility to convert a URDF into USD format. Unified Robot Description Format (URDF) is an XML file format used in ROS to describe all elements of a robot. For more information, see: http://wiki.ros.org/urdf This script uses the URDF importer extension from Isaac Sim (``isaacsim.asset.importer.urdf``) to convert a URDF asset into USD format. It is designed as a convenience script for command-line use. For more information on the URDF importer, see the documentation for the extension: https://docs.isaacsim.omniverse.nvidia.com/latest/robot_setup/ext_isaacsim_asset_importer_urdf.html positional arguments: input The path to the input URDF file. output The path to store the USD file. optional arguments: -h, --help Show this help message and exit --merge-joints Consolidate links that are connected by fixed joints. (default: False) --fix-base Fix the base to where it is imported. (default: False) --joint-stiffness The stiffness of the joint drive. (default: 100.0) --joint-damping The damping of the joint drive. (default: 1.0) --joint-target-type The type of control to use for the joint drive. (default: "position") """ """Launch Isaac Sim Simulator first.""" import argparse from isaaclab.app import AppLauncher # add argparse arguments parser = argparse.ArgumentParser(description="Utility to convert a URDF into USD format.") parser.add_argument("input", type=str, help="The path to the input URDF file.") parser.add_argument("output", type=str, help="The path to store the USD file.") parser.add_argument( "--merge-joints", action="store_true", default=False, help="Consolidate links that are connected by fixed joints.", ) parser.add_argument("--fix-base", action="store_true", default=False, help="Fix the base to where it is imported.") parser.add_argument( "--joint-stiffness", type=float, default=100.0, help="The stiffness of the joint drive.", ) parser.add_argument( "--joint-damping", type=float, default=1.0, help="The damping of the joint drive.", ) parser.add_argument( "--joint-target-type", type=str, default="position", choices=["position", "velocity", "none"], help="The type of control to use for the joint drive.", ) # append AppLauncher cli args AppLauncher.add_app_launcher_args(parser) # parse the arguments args_cli = parser.parse_args() # launch omniverse app app_launcher = AppLauncher(args_cli) simulation_app = app_launcher.app """Rest everything follows.""" import contextlib import os import carb import omni.kit.app import isaaclab.sim as sim_utils from isaaclab.sim.converters import UrdfConverter, UrdfConverterCfg from isaaclab.utils.assets import check_file_path from isaaclab.utils.dict import print_dict def main(): # check valid file path urdf_path = args_cli.input if not os.path.isabs(urdf_path): urdf_path = os.path.abspath(urdf_path) if not check_file_path(urdf_path): raise ValueError(f"Invalid file path: {urdf_path}") # create destination path dest_path = args_cli.output if not os.path.isabs(dest_path): dest_path = os.path.abspath(dest_path) # Create Urdf converter config urdf_converter_cfg = UrdfConverterCfg( asset_path=urdf_path, usd_dir=os.path.dirname(dest_path), usd_file_name=os.path.basename(dest_path), fix_base=args_cli.fix_base, merge_fixed_joints=args_cli.merge_joints, force_usd_conversion=True, joint_drive=UrdfConverterCfg.JointDriveCfg( gains=UrdfConverterCfg.JointDriveCfg.PDGainsCfg( stiffness=args_cli.joint_stiffness, damping=args_cli.joint_damping, ), target_type=args_cli.joint_target_type, ), ) # Print info print("-" * 80) print("-" * 80) print(f"Input URDF file: {urdf_path}") print("URDF importer config:") print_dict(urdf_converter_cfg.to_dict(), nesting=0) print("-" * 80) print("-" * 80) # Create Urdf converter and import the file urdf_converter = UrdfConverter(urdf_converter_cfg) # print output print("URDF importer output:") print(f"Generated USD file: {urdf_converter.usd_path}") print("-" * 80) print("-" * 80) # Determine if there is a GUI to update: # acquire settings interface carb_settings_iface = carb.settings.get_settings() # read flag for whether a local GUI is enabled local_gui = carb_settings_iface.get("/app/window/enabled") # read flag for whether livestreaming GUI is enabled livestream_gui = carb_settings_iface.get("/app/livestream/enabled") # Simulate scene (if not headless) if local_gui or livestream_gui: # Open the stage with USD sim_utils.open_stage(urdf_converter.usd_path) # Reinitialize the simulation app = omni.kit.app.get_app_interface() # Run simulation with contextlib.suppress(KeyboardInterrupt): while app.is_running(): # perform step app.update() if __name__ == "__main__": # run the main function main() # close sim app simulation_app.close()