Overview

This tutorial describes the process of creating a model using the Model Editor.

Open the Model Editor

1. Make sure Gazebo is installed.

2. Start up gazebo.

   $ gazebo
   

3. On the Edit menu, go to Model Editor, or hit Ctrl+M to open the editor.

   

Graphical user interface

The editor is composed of the following 2 areas:

• The Palette on the left where you can select links and insert them into the scene to build the model.

• The 3D View on the right where you can see a preview of your model and interact with it to edit its properties and create joints between links.

The GUI tools on the top toolbar can be used to manipulate joints and links in the 3D View.

Add Links

Add simple shapes

The model editor has three simple primitive geometries that the user can insert into the 3D view to make a link of the model.

1. On the Palette, click on the box, sphere, or cylinder icon under Simple Shapes.

2. Move your mouse cursor over the 3D view to see the visual appear, and click/release anywhere to add it to the model.

   Tip: You can press Esc to cancel adding the current link attached to the mouse cursor.

   

Add meshes

To add a custom mesh,

1. Click on the Add button under Custom Shapes, which pops up a dialog that lets you find the mesh you want to add.

2. Click on Browse button and use the file browser to find the mesh file on your local machine. If you know the path of the mesh file, you can enter it directly in the text field box next to the Browse button. Note Gazebo currently only supports importing COLLADA (dae), STereoLithography (stl), and Scalable Vector Graphics (svg) files.

3. Click Import to load the mesh file. Then, add it to the 3D view.

   

Create Joints

The model editor supports creating several types of joints between links in the model being edited. To create a joint:

1. Click on the joint icon on the tool bar. This defaults to a revolute joint which you can edit its type later. Alternatively, click on the small arrow at the bottom right corner of the joint icon to choose a specific joint type.

2. Once the joint type is selected, move your mouse over the link you wish to create a joint for to see it being highlighted and click on it. This link will be the parent link of the joint.

3. Next, move your mouse to the link which you would like to be the child link of the joint. Click on it to finalize the joint creation process and see a colored line connecting the two links and a joint visual attached to the child link.

   Tip: You can press Esc to cancel the joint creation process.

   

The line representing the joint is color-coded. Play around with different joint types to see the colors.

The joint visual consists of RGB axes which help to give an idea of the coordinate frame of the joint. The yellow arrow indicates the primary axis of the joint. For example, in the case of a revolute joint, this is the axis of rotation.

Edit your model

Note: Be careful when editing your model; the editor currently has no option to undo your actions.

Tip: All measurements are in meters.

Edit links

The model editor supports editing properties of a link which you would also find in its SDF.

Note: Gazebo 6 supports editing links, visuals, and collisions. The ability to edit sensors and plugins are to be implemented in later versions.

To edit a link's properties: Double-click on the link or right click and select Open Link Inspector. A dialog window will appear which contains Link, Visual, and Collision property tabs.

As an example, try changing the link pose and visual colors. Click on Apply to see the changes reflected in the 3D view. Once you are done, click on OK to close the inspector.

Edit joints

As mentioned earlier, joint properties can also be edited. These are properties that you would find in the joint SDF.

To edit a joint: Double-click on the line connecting the links or right click on it and select Open Joint Inspector. The joint inspector will appear.

As an example, try changing the joint pose and joint type. Click on Apply to see the changes reflected in the 3D view. Once you are done, click on OK to close the inspector.

Saving your model

Saving will create a directory, SDF and config files for your model.

As an exercise, let's build a simple car and save it. The car will have a box chassis and four cylinder wheels. Each wheel will be connected to the chassis with a revolute joint:

Once you're happy with the model you created. Let's save it.

Before saving, give your model a name on the Palette.

On the top menu, choose File, then Save As (or hit Ctrl+S). A dialog will come up where you can choose the location for your model.

Exit

When you're done creating your model and you've saved it, go to File and then Exit Model Editor.

Your model will show up in the main window.

Edit existing models

Rather than creating a model from the ground up with simple shapes and meshes, you can also edit existing models that are already in the simulation.

To edit an existing model:

• Make sure you have saved the model you've created and are now back to the normal gazebo mode. Alternatively, start from a fresh gazebo instance.

• Insert a model from the Insert tab of the left. For example, let's insert a Simple Arm.

• Right click on the model you just inserted and select Edit Model.

Now you are in the model editor mode and you are free to add new links to the model or edit existing ones.