MJCF2USD

A powerful Isaac Sim extension for converting MuJoCo XML Configuration Format (MJCF) files to Universal Scene Description (USD) format.

Welcome to the Lightwheel open-source community!

Join us, contribute, and help shape the future of AI and robotics. For questions or collaboration, contact Frank Chen at ming.chen@lightwheel.ai.

Overview

MJCF2USD is a user-friendly tool that enables seamless conversion of MuJoCo simulation files to USD format, making it easy to integrate MuJoCo models into Omniverse workflows and other USD-compatible applications.

Features

• Batch Conversion: Convert multiple MJCF files at once
• Intuitive UI: Simple and clean interface with step-by-step guidance
• Flexible Output: Choose custom output locations or use default paths
• Progress Tracking: Real-time conversion progress with time estimates
• Error Handling: Detailed success/failure reporting
• XML Modification: Optional temporary XML file saving for debugging

Installation

Prerequisites

• NVIDIA Isaac Sim

Installation Steps

1. Clone this repository to your Omniverse extensions directory:

   git clone <repository-url> /path/to/isaacsim/extensions
   

2. Enable the extension through the Extensions Manager in Isaac Sim.

3. Set the Import Path in Isaac Sim:

   • Open Isaac Sim and go to Window > Extensions.
   • Click the Settings (gear) icon.
   • In the Extension Search Paths section, click the + button.
   • Copy and paste the parent path of the mjcf2usd folder (the path where you cloned this repository).

📄 For detailed step-by-step instructions with screenshots, please refer to Installation.pdf included in this repository.

Usage

Getting Started

1. Launch the Extension:

   • Open IsaacSim
   • Go to Window > Extensions.
   • Enable "MJCF2USD" extension
   • The MJCF2USD window will appear

2. Select MJCF Files:

   • Click "Select File or Folder" in step 1
   • Choose either a single MJCF file or a folder containing multiple MJCF files
   • The extension will automatically scan and list all found MJCF files

3. Choose Output Location (Optional):

   • Click "Select Folder" in step 2
   • Choose where you want the USD files to be saved
   • If left empty, USD files will be saved in the same directory as the MJCF files

4. Configure Options:

   • Check "Save Temp MJCF XML" if you want to save modified XML files for debugging

5. Start Conversion:

   • Click "MJCFs to USDs" button
   • Monitor the progress in the status area
   • View conversion results and timing information

Output

• Success: USD files will be created in the specified output location
• File Naming: Output files follow the pattern {parent_folder}_{filename}.usd
• Reports: Detailed conversion statistics including:
  • Total conversion time
  • Number of successful conversions
  • Number of failed conversions
  • List of successful and failed files

Project Structure

MJCF2USD/
├── config/
│   └── extension.toml          # Extension configuration
├── data/
│   ├── logo.png               # Extension icon
│   └── preview.jpeg           # Extension preview image
├── lightwheel/
│   └── MJCF2USD/
│       └── connection/
│           ├── extension.py   # Main extension entry point
│           ├── window.py      # UI window implementation
│           ├── mjcf2usd_utils.py  # Core conversion utilities
│           ├── option_widget.py   # UI components
│           ├── ui_utils.py    # UI utility functions
│           └── style.py       # UI styling
├── LICENSE.txt                # License file
└── README.md                  # This file

Development

Dependencies

• omni.kit.uiapp: Omniverse UI framework
• omni.ui: Omniverse UI components
• omni.usd: USD manipulation utilities
• omni.kit.commands: Omniverse command system

Building

The extension is built using Omniverse Kit's extension system. No additional build steps are required beyond the standard Python module structure.

Version

Current version: 1.0.0

Support

For issues and questions, please contact the development team or create an issue in the repository.