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Expand LaserScan in rviz and set the topic to /scan, looks like the values are being published correctly so they should

@mgruhler Sorry but I think you misunderstood my issue, It's not that I can't "SEE" the scan properly, so changing the s

ROS Melodic, Ubuntu18, Gazebo9

Issue: Not able to visualize laser scan data in rviz

Error: No tf data. Actual error: Fixed Frame [map] does not exist

Steps to recreate:

1. Launch gazebo with ros
   roslaunch gazebo_ros empty_world.launch
2. Insert Hokuyo laser sensor. Go to the insert tab in gazebo and add the hokuyo model to the world. Also add a few blocks near the sensor (for visualization).
3. Open rviz
   rviz

Rviz gives the error as mentioned above. I have done rostopic list and saw that there was /laser/scan topic, but there was no /tf topic. I added the LaserScan visualisation to rviz.

I did rostopic echo on /laser/scan and the data was actually being published properly. I am not doing slam or anything, I just want to visualize the scan data in rviz.

Who publishes this map frame? Should I be publishing this? If so, how should I?

Thank You! This worked. I understand that the key here was the *_state_publisher nodes. rostopic info showed that the tf

Thank You! This worked. I understand that the key here was the *_state_publisher nodes. rostopic info indeed showed that

After running bringup, check if the topics are being published or not using rostopic echo <topicName>

The frame_id in the /laser/scan topic is indeed set to map. But in rviz the dropdown menu for Fixed Frame is empty. Even

There are no tf frames at all. As u can see in the above comment that the frame is set to map in the plugin, but there a

The included hokuyo model does use a laser plugin. <plugin name="laser" filename="libRayPlugin.so" /> <plu

Who publishes the map frame? ROS Melodic, Ubuntu18, Gazebo9 Issue: Not able to visualize laser scan data in rviz Error

I am using ros melodic on ubuntu18. I was following the tutorials on tf2, so after going through the broadcaster and listener, the start demo launch file is not launching the listener node. What is even weirder to me is that it works (without giving an error) when I launch the file directly from the folder i.e.

roslaunch start_demo.launch

instead of

roslaunch learning_tf2 start_demo.launch

Here is my launch file

<launch>
<node pkg="turtlesim" type="turtlesim_node" name="sim"/>
<node pkg="turtlesim" type="turtle_teleop_key" name="teleop" output="screen"/>


<node name="turtle1_tf2_broadcaster" pkg="learning_tf2" type="turtle_tf2_broadcaster.py" respawn="false" output="screen" >
  <param name="turtle" type="string" value="turtle1" />
</node>
<node name="turtle2_tf2_broadcaster" pkg="learning_tf2" type="turtle_tf2_broadcaster.py" respawn="false" output="screen" >
  <param name="turtle" type="string" value="turtle2" /> 
</node>
<node name="turtle_listener" pkg="learning_tf2" type="turtle_tf2_listener.py" output="screen"/></launch>

I have done things like deleting my devel and build folders, running catkin_make, sourcing setup.bash, but still the same issue. Am I missing something here? When I run from the folder directly:

NODES
  /
    sim (turtlesim/turtlesim_node)
    teleop (turtlesim/turtle_teleop_key)
    turtle1_tf2_broadcaster (learning_tf2/turtle_tf2_broadcaster.py)
    turtle2_tf2_broadcaster (learning_tf2/turtle_tf2_broadcaster.py)
    turtle_listener (learning_tf2/turtle_tf2_listener.py)

When I reference through package:

NODES
  /
    sim (turtlesim/turtlesim_node)
    teleop (turtlesim/turtle_teleop_key)
    turtle1_tf2_broadcaster (learning_tf2/turtle_tf2_broadcaster.py)
    turtle2_tf2_broadcaster (learning_tf2/turtle_tf2_broadcaster.py)

It's the same launch file! What am I missing here?

I am sorry, I realized the mistake later. What's happening is that I had another workspace with the same package name an

roslaunch is not launching all nodes I am using ros melodic on ubuntu18. I was following the tutorials on tf2, so after