Gazebo: make an animated box using a separate model file(s)

The Gazebo tutorial at http://gazebosim.org/tutorials?tut=actor&cat=build_robot shows how to make a box actor rotate around the vertical axis using only a world file. I wanted to use create a separate actor model and include it in the world file so I don't have to repeat the code. After fiddling around, I managed to figure out the procedure to do it. This post summarizes the steps.

Create an actor model

1. In the user's home directory ~/.gazebo/models/, create a model folder, e.g. animated_box
   
   $ cd ~/.gazebo/models/
   $ mkdir -p animated_box/materials/scripts
   $ mkdir -p animated_box/materials/textures
   
   
2. Change directory into the animated_box folder.
   
   $ cd animated_box
   
   
   
3. Using a text editor, create a model.config file. Type in the following:
   

   <?xml version="1.0" encoding="utf-8"?>
   <model>
    <name>Animated Box</name>
    <version>1.0</version>
    <sdf version="1.4">model.sdf</sdf>
    <description>My animated box</description>
   </model>
   

   
   
   
4. Using a text editor, create a model.sdf file. Type in the following:
   
   Note: instead of the model tag, use the actor tag.
   

   <?xml version="1.0" encoding="utf-8"?>
   <sdf version="1.4">
    <actor name="animated_box">
     <static>false</static>
      <link name="link">
       <visual name="visual">
        <geometry>
         <box>
          <size>0.2 0.2 0.2</size>
         </box>
        </geometry>
       </visual>
      </link>
      <script>
       <loop>true</loop>
       <delay_start>0.0</delay_start>
       <auto_start>true</auto_start>
       <trajectory id="0" type="square">
        <waypoint>
         <time>0.0</time>
         <pose>-1 -1 1 0 0 0</pose>
        </waypoint>
        <waypoint>
         <time>1.0</time>
         <pose>-1 1 1 0 0 0</pose>
        </waypoint>
        <waypoint>
         <time>2.0</time>
         <pose>1 1 1 0 0 0</pose>
        </waypoint>
        <waypoint>
         <time>3.0</time>
         <pose>1 -1 1 0 0 0</pose>
        </waypoint>
        <waypoint>
         <time>4.0</time>
         <pose>-1 -1 1 0 0 0</pose>
        </waypoint>
       </trajectory>
      </script>
   
    </actor>
   </sdf>
   

   
   
   

Create and run the world file

1.  Using a text editor, create a world file, e.g. my_animated_box.world. Type in the following commands:
   

   <?xml version="1.0" ?>
   <sdf version="1.3">
    <world name="default">
     <include>
     <uri>model://sun</uri>
     </include>
     <include>
      <uri>model://ground_plane</uri>
     </include>
     <include>
      <uri>model://animated_box</uri>
     </include>
    </world>
   </sdf>
   

   
   Note: the previously created animated_box model is included as a model.
   
   
2. Run the world file.
   
   $ gazebo my_animated_box.world
   
   Gazebo opens and an animated box is shown circling the z axis.