In Gazebo 1.5 (the version packaged with ROS Groovy), I set gazebo_media_path in package.xml like this:

  <run_depend>gazebo</run_depend>
  <export>
    <gazebo gazebo_media_path="${prefix}"/>
  </export>

In my world file, I specified materials and meshes like this:

  <material>
    <script>
      <name>cerberus_gazebo/srrc_terrain</name>
    </script>
  </material>

  <geometry>
    <mesh>
      <uri>file://restroom_bldg.dae</uri>
    </mesh>
  </geometry>

The materials and meshes were defined in subdirectories of my Media directory, which was in the same directory as package.xml. Gazebo rendered the world correctly.

I have now moved to Gazebo 1.8.6 and I get the following warnings and errors:

  Warning [Visual.cc:775] Unable to get Material[cerberus_gazebo/srrc_terrain] for
    Geometry[terrain::link::visual. Object will appear white
  Error [SystemPaths.cc:370] File or path does not exist[""]
  Error [Visual.cc:2075] No mesh specified

My materials and meshes are no longer found. Is gazebo_media_path no longer supported? I tried adding my package directory to GAZEBO_RESOURCE_PATH (i.e. I added the directory that contains package.xml and Media), but that had no effect.

  <run_depend>gazebo_ros</run_depend>
  <export>
    <gazebo_ros gazebo_media_path="${prefix}"/>
  </export>