How to include two or more models in sdf

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Hello everyone, I'm working with PX4 and I'm trying to add two realsense cameras to the iris drone, one pointing forward and one pointing down, but when I include the two models the second camera topics overwrite the first ones. I know this happens because they have the same namespaces but I can't figure out how to distinguish them inside the sdf file in order to have, for example:

• /camera_front/depth/image
• /camera_down/depth/image

The sdf I'm using for the drone is the following:

<sdf version='1.5'>
<model name='iris_realsense'>

<include>
  <uri>model://iris</uri>
</include>

<include>
  <uri>model://r200</uri>
  <name>front_camera</name>
  <pose>0.2 0 0 0 0 0</pose>
</include>

<include>
  <uri>model://r200</uri>
  <name>down_camera</name>
  <pose>0 0 -0.05 0 1.57 0</pose>
</include>

<joint name="fpv_cam_joint" type="fixed">
  <parent>iris::base_link</parent>
  <child>front_camera::link</child>
  <axis>
    <xyz>0 0 1</xyz>
    <limit>
      <upper>0</upper>
      <lower>0</lower>
    </limit>
  </axis>
</joint>

<joint name="fpv_cam_joint2" type="fixed">
  <parent>iris::base_link</parent>
  <child>down_camera::link</child>
  <axis>
    <xyz>0 0 1</xyz>
    <limit>
      <upper>0</upper>
      <lower>0</lower>
    </limit>
  </axis>
</joint>

</model>
</sdf>

and the realsense sdf included is:

<plugin name="r200_controller" filename="libgazebo_ros_camera.so">
   <ros>
      <namespace>custom_ns</namespace>
      <argument>custom_camera/image_raw:=custom_camera/custom_image</argument>
      <argument>custom_camera/image_depth:=custom_camera/custom_image_depth</argument>
      <argument>custom_camera/camera_info:=custom_camera/custom_info_raw</argument>
      <argument>custom_camera/camera_info_depth:=custom_camera/custom_info_depth</argument>
      <argument>custom_camera/points:=custom_camera/custom_points</argument>
    </ros>
    <frameName>r200</frameName>
</plugin>

Thanks for your help!