plugin_description.xml

<library path="lib/librviz_lighting">
  <class name="rviz_lighting/AmbientLight"
         type="rviz_lighting::AmbientLightDisplay"
         base_class_type="rviz::Display">
    <description>
      Set the ambient light value for the scene.
    </description>
  </class>
  <class name="rviz_lighting/Light"
         type="rviz_lighting::LightDisplay"
         base_class_type="rviz::Display">
    <description>
      Add a directional, point, or spot light to the scene.
    </description>
  </class>
</library>