Import Fusion360 Model to Gazebo

(Based on wonderful work by SpaceMaster85, with modifications to support the latest Fusion version.)

This guide provides instructions for setting up the environment to import models from Fusion 360 into Gazebo. The conversion process relies on a tool in ROS 2, so ROS 2 must also be installed.

This setup uses Ubuntu Noble 24.04 + Gazebo Harmonic + ROS 2 Jazzy Jalisco, but other Ubuntu and ROS 2 versions should work. Gazebo Harmonic is recommended for compatibility. For issues with other versions of Gazebo, see Troubleshooting in Gazebo at the end.

Table of Contents

1. Prerequisites
2. Export Fusion360 Model
3. Import to Gazebo
4. Fusion Model Settings
5. Troubleshooting in Gazebo

1 Prerequisites

Installing ROS 2 and Gazebo

1. Check your Ubuntu version:

lsb_release -a

2. Identify the recommended versions for your system:

• Check compatible Gazebo versions: https://gazebosim.org/docs/fortress/getstarted/
• Refer to ROS installation recommendations: https://gazebosim.org/docs/fortress/ros_installation/

3. Install ROS 2 :

• If you are intalling ROS 2 jazzy, use:

https://docs.ros.org/en/jazzy/Installation/Alternatives/Ubuntu-Development-Setup.html

• For other ROS 2 versions, refer to the general ROS 2 installation documentation:

  https://docs.ros.org/en/

4. Install Gazebo Harmonic:

• For the recommended Gazebo version, see the Gazebo Harmonic Installation Guide: https://gazebosim.org/docs/harmonic/install_ubuntu/

Environment Configuration

Configure your shell to automatically source the ROS 2 environment each time you open a terminal:

# For Zsh users:
echo "source /opt/ros/${ROS_DISTRO}/setup.zsh" >> ~/.zshrc
source ~/.zshrc

# For Bash users:
echo "source /opt/ros/${ROS_DISTRO}/setup.bash" >> ~/.bashrc
source ~/.bashrc

Install the xacro Package

The xacro package, part of ROS 2, is necessary for converting files from .xacro to .urdf format.

sudo apt install ros-${ROS_DISTRO}-xacro

2 Export Fusion360 Model

This section is based on a fork from https://github.com/SpaceMaster85/fusion2urdf. The original project is no longer maintained, so I have updated it to be compatible with the latest version of Fusion 360.

Installation

Clone this repo

 git clone [email protected]:YanningDai/Import_Fusion_Model_to_Gazebo.git

Note: By default, this setup uses ROS 2; however, if you need ROS 1, set the variable ros_version_is_ros1 to True in the Import_Fusion_Model_to_Gazebo/URDF_Exporter.py file.

Run the following command in your shell:

- Windows (In PowerShell)

cd Import_Fusion_Model_to_Gazebo
Copy-Item ".\URDF_Exporter\" -Destination "${env:APPDATA}\Autodesk\Autodesk Fusion 360\API\Scripts\" -Recurse

- macOS (In bash or zsh)

cd Import_Fusion_Model_to_Gazebo
cp -r ./URDF_Exporter "$HOME/Library/Application Support/Autodesk/Autodesk Fusion 360/API/Scripts/"

Model Export

• Important: Before exporting, check your model settings in Fusion Model Settings.

• Once your model is ready, go to ADD-INS in Fusion 360 and select URDF_Exporter.

• Run the script and wait for the process to complete (this may take a few seconds or minutes). A folder dialog will then appear—select your desired location for the output files.

• The script will create a folder named after your Fusion 360 model in lowercase, followed by "_description". For example, "robot_description".

3 Import to Gazebo

Convert the xacro file to SDF format and view it in Gazebo.

# Navigate to an empty project folder for the output .sdf file
cd /path/to/empty/folder
mkdir src

# Copy files from Fusion 360 output to the src folder
# Replace `robot` with your Fusion360 model's name
export MODEL_NAME=robot
scp -r "/path/to/fusion360/output/${MODEL_NAME}_description" src 

# Build xacro
colcon build
source install/setup.bash  # in zsh: source install/setup.zsh

# Convert xacro -> urdf -> sdf
xacro src/${MODEL_NAME}_description/urdf/${MODEL_NAME}.xacro > src/${MODEL_NAME}_description/urdf/${MODEL_NAME}.urdf
gz sdf -p src/${MODEL_NAME}_description/urdf/${MODEL_NAME}.urdf > src/${MODEL_NAME}_description/urdf/${MODEL_NAME}.sdf

# Then, the generated `.sdf` file and the `meshes` folder (under src/${MODEL_NAME}_description) are what you need for gazebo.

# Set up the Gazebo resource path and preview in Gazebo
export GZ_SIM_RESOURCE_PATH=$(pwd)/src/
gz sim src/${MODEL_NAME}_description/urdf/${MODEL_NAME}.sdf

Note:

1. Replace /path/to/empty/folder with the path to an empty directory for your project.
2. Replace /path/to/fusion360/output with the path of your Fusion 360 export files.
3. Update robot with the name of your Fusion360 model.

4 Fusion Model Settings

Links

• Ensure all links are set as components in Fusion 360 by creating corresponding components.

Joint Constraints

• Supported Joint Types: Only "Rigid," "Slider," and "Revolute" joints are supported.
• Parent links should be set as Component2 when defining a joint. Setting "base_link" as Component1, for instance, will cause a "KeyError: base_link__1" error.

Export Limitations

• Nested components are exported as a single STL file; only root-level joints are processed, while joints in nested or lower-level components are ignored.
• Only components and bodies with active light bulbs are exported; those with deactivated light bulbs are ignored. Components connected by deactivated joints will not be exported.

Colors

• Colors defined at the root level of components are retained and included in the URDF file’s material definitions.

Troubleshooting

• Occasionally, the script may export an abnormal URDF without error messages. If this occurs, try redefining the joints and running the export again.

For more details and examples, see: https://github.com/SpaceMaster85/fusion2urdf

5 Troubleshooting in Gazebo

1. If gz sim loads the SDF model but doesn’t display it, try setting the mesh scale to 1:1:1 as it may be too small.

2. If the SDF file can’t find the model path, it could be due to a version mismatch. Use gz sim -h to check environment variables, and update export GZ_SIM_RESOURCE_PATH to match the model path variable in your version. Some Gazebo versions use GAZEBO_MODEL_PATH as the path for models.

3. Materials aren’t set, so inertial matrix and mass parameters might be incorrect, but this won’t affect the display.

4. If the Gazebo world doesn’t update and remains in a previous state, clear the Gazebo cache with:

   pkill -f gz
   ps aux | grep gz