Custom World Gazebo Problem

[roduralde93]

Hi!
I’ve been following some old Constructsim YouTube tutorials on how to create a custom world on Gazebo, but I’m having some difficulties replicating what it shown on the video in my local machine.

So I have the same package structure as shown in the video, meaning I have a package named my_simulations, with a world file inside a world folder, and a launch file inside the launch folder (both executable)

Inside this world file I define a world with nothing but a ground plane, a sun and a postbox (an existing model inside the gazebo package, as explained in the video).
This is the world file:

<?xml version="1.0" ?>
<sdf version="1.5">
  <world name="default">
    <!-- A global light source -->
    <include>
      <uri>model://sun</uri>
    </include>
    <!-- A ground plane -->
    <include>
      <uri>model://ground_plane</uri>
    </include>
    <include>
      <uri>model://postbox</uri>
    </include>
  </world>
</sdf>

And this is the launch file:

<?xml version="1.0" encoding="UTF-8"?>

<launch>
    <arg name="debug" default="false" />
    <arg name="gui" default="true" />
    <arg name="pause" default="false" />
    <arg name="world" default="$(find my_simulations/world/empty_world.world" />

    <include file="$(find gazebo_ros)/launch/empty_world.launch">
        <arg name="world_name" value="$(arg world)"/>
        <arg name="debug" value="$(arg debug)"/>
        <arg name="gui" value="$(arg gui)"/>
        <arg name="paused" value="$(arg pause)"/>    
        <arg name="use_sim_time" value="true"/>
    </include>

</launch>

Both exactly as shown in the tutorial.
My problem is that, when I launch this package (which launches without issues), gazebo just opens an empty world, not recognizing the one I specified with the postbox.
I’ve tried to edit the files to somehow get a different output, but there’s nothing getting included in the empty world.
I tried removing the build and devel folders also and recompiling the package, with no luck.
Could you please help me understand what’s wrong here?
Thanks in advance!