git_ws/MPC/launch/gazebo_launch/mud_world.launch

<?xml version="1.0"?>
<launch>

  <!-- We resume the logic in empty_world.launch, changing only the name of the world to be launched -->
  <include file="$(find gazebo_ros)/launch/empty_world.launch">
    <arg name="world_name" value="worlds/mud.world"/> <!-- Note: the world_name is with respect to GAZEBO_RESOURCE_PATH environmental variable -->
    <arg name="paused" value="false"/>
    <arg name="use_sim_time" value="true"/>
    <arg name="gui" value="true"/>
    <arg name="headless" value="false"/> <!-- Inert - see gazebo_ros_pkgs issue #491 -->
    <arg name="recording" value="false"/>
    <arg name="debug" value="false"/>
  </include>

</launch>