could not find camera topic on rviz

Question

I was launching the techman robot on ros using the demo.launch. The first time when I launched it on rviz I could able to see the camera under by topic and I can see the video output. So I edited the moveit setup and added some poses to the robot. so when I launched again. now I could not find a camera under by topic. And I am very new to ros.

and the following was my demo.launch file

<launch>

  <!-- specify the planning pipeline -->
  <arg name="pipeline" default="ompl" />

  <!-- By default, we do not start a database (it can be large) -->
  <arg name="db" default="false" />
  <!-- Allow user to specify database location -->
  <arg name="db_path" default="$(find new_techman)/default_warehouse_mongo_db" />

  <!-- By default, we are not in debug mode -->
  <arg name="debug" default="false" />

  <!-- By default, we will load or override the robot_description -->
  <arg name="load_robot_description" default="true"/>

  <!-- Set execution mode for fake execution controllers -->
  <arg name="execution_type" default="interpolate" />

  <!--
  By default, hide joint_state_publisher's GUI

  MoveIt!'s "demo" mode replaces the real robot driver with the joint_state_publisher.
  The latter one maintains and publishes the current joint configuration of the simulated robot.
  It also provides a GUI to move the simulated robot around "manually".
  This corresponds to moving around the real robot without the use of MoveIt.
  -->
  <arg name="use_gui" default="false" />
  <arg name="use_rviz" default="true" />

  <!-- If needed, broadcast static tf for robot root -->


  <!-- We do not have a robot connected, so publish fake joint states -->
  <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher" unless="$(arg use_gui)">
    <rosparam param="source_list">[move_group/fake_controller_joint_states]</rosparam>
  </node>
  <node name="joint_state_publisher" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui" if="$(arg use_gui)">
    <rosparam param="source_list">[move_group/fake_controller_joint_states]</rosparam>
  </node>

  <!-- Given the published joint states, publish tf for the robot links -->
  <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" respawn="true" output="screen" />

  <!-- Run the main MoveIt! executable without trajectory execution (we do not have controllers configured by default) -->
  <include file="$(find new_techman)/launch/move_group.launch">
    <arg name="allow_trajectory_execution" value="true"/>
    <arg name="fake_execution" value="true"/>
    <arg name="execution_type" value="$(arg execution_type)"/>
    <arg name="info" value="true"/>
    <arg name="debug" value="$(arg debug)"/>
    <arg name="pipeline" value="$(arg pipeline)"/>
    <arg name="load_robot_description" value="$(arg load_robot_description)"/>
  </include>

  <!-- Run Rviz and load the default config to see the state of the move_group node -->
  <include file="$(find new_techman)/launch/moveit_rviz.launch" if="$(arg use_rviz)">
    <arg name="rviz_config" value="$(find new_techman)/launch/moveit.rviz"/>
    <arg name="debug" value="$(arg debug)"/>
  </include>

  <!-- If database loading was enabled, start mongodb as well -->
  <include file="$(find new_techman)/launch/default_warehouse_db.launch" if="$(arg db)">
    <arg name="moveit_warehouse_database_path" value="$(arg db_path)"/>
  </include>

</launch>

and when I launch the gazebo.launch that was created by the moveit setup assistant I can see the camera from the gazebo platform into rviz

Looking for camera topics might be easier using the "by display type" tab, but it doesn't seem to be published. Can you share your launch-file? — Jere
while you're on it: Could you also share -> the command line output, ROS produces when the launch file is executed and -> the output of rostopic list? — Jere
I'm not sure I understand correctly. When you launch gazebo.launch, you CAN see the camera in rviz? What is missing then? :D — Jere
so let me brief it for you. first i tried to create a world in gazebo tried adding my robot into the world. when i tried that some parts of robots was not properly imported. So then i decided to create a world on rviz itself and placed some boxes. but when i launch both rviz only. i cannot see the camera topic. once i launch gazebo.launch on another terminal. i can see there is a topic on camera is publishing. when i try to add camera topic into rviz. i am getting the camera output from the gazebo world. i cannot get the camera output from the robot in rviz platform — Akash

Jere Jere · Accepted Answer · 2021-07-23T10:34:13

Have you launched Gazebo before or after launching your demo.launch? Try doing it the other way around!

It seems that Gazebo provides your camera-simulation. Rviz itself doesn't create the camera view, it just listens to a topic where a different engine (normally a robot, in your case the robot-simulation of Gazebo) publishes the images and then shows these images to you.

Rviz and Gazebo sometimes have trouble communicating based on which is started first.

could not find camera topic on rviz

1 Answers