rtabmap_ros/rtabmap_examples/launch/tests/test_map_optimizer.launch

<?xml version="1.0"?>
<launch>
   <include file="$(find rtabmap_ros)/launch/rtabmap.launch">
     <arg name="rtabmap_args" value="
                                     --delete_db_on_start
                                     --RGBD/OptimizeMaxError 0
                                     --Optimizer/Iterations 0
                                     --RGBD/ProximityBySpace false"/>
     <arg name="rtabmapviz" value="false"/>
  </include>

  <group ns="rtabmap">
     <node pkg="rtabmap_ros" type="map_optimizer" name="map_optimizer"/>

     <node pkg="rtabmap_ros" type="rtabmapviz" name="rtabmapviz" output="screen">
        <remap from="mapData" to="mapData_optimized"/>
        <param name="frame_id" value="camera_link"/>
        <param name="subscribe_depth" value="false"/>
     </node>

     <node pkg="rtabmap_ros" type="map_assembler" name="map_assembler">
        <remap from="mapData" to="mapData_optimized"/>
     </node>
  </group>
</launch>