无法显示点云

[2805651606]

都运行成功，也没有任何报错。但是就是无法显示点云

[tipodgorsk]

Hi @2805651606, it seems that you are trying to display data coming from the topic "octomap_point_cloud_centers" (aka sensor_msgs::msg::PointCloud2), as an occupancy grid. I don't think it's possible.

1. Make sure that you are filling a topic with "sensor_msgs::msg::PointCloud2". Let's call this topic "/your_topic"
   Use "ros2 topic echo /your_topic" to check it.

2. launch the octomap_server2 node with "ros2 launch octomap_server2 octomap_server_launch.py input_cloud_topic:=/your_topic". You can find all parameters which can be remapped in "launch/octomap_server_launch.py".

3. You can display the occupancy grid in rviz2 by clicking on "Display --> by_topic --> /projected_map"

If it's still not working, please try to give me as much information as possible

[2805651606]

也是按照老哥你的步骤提示的做的，就是会显示[octomap_server-1] [INFO] [1720579298.740991451] [octomap_server]: Message Filter dropping message: frame 'camera_depth_optical_frame' at time 1720579298.534 for reason 'discarding message because the queue is full' 这么个错误
点云数据可以发布

[tipodgorsk]

Can you tell me what the purpose of the node at the bottom-left is ? I suppose it's a visual slam node. But it has no name.

Regarding on your MessageFilter issue, it seems that you don't have a full tf tree.

A message filter is an object that filter every message consumed by a subscriber, by checking if a transform with appropriate timestamp between the message frame_id and a reference frame_id is available (in this case, the reference frame_id is "map" by default).

So if you don't generate any tf between your pointcloud_msg frame_ids and a world frame, this won't work.
Refer to the following issue :

https://answers.ros.org/question/389383/slam_toolbox-message-filter-dropping-message-for-reason-discarding-message-because-the-queue-is-full/

To understand and generate a tf tree, see :

https://articulatedrobotics.xyz/tutorials/ready-for-ros/tf/

https://docs.ros.org/en/foxy/Tutorials/Intermediate/URDF/Using-URDF-with-Robot-State-Publisher.html

[2805651606]

你好，我现在已经可以显示点云图了，但是我再利用ros2 run nav2_map_server map_saver_cli -t /project_map -f fishbot_map进行建图的时候，就会报错。把/project_map的/去掉，也是报同样的错误。请问这是怎么回事呢

[tipodgorsk]

This problem does not concern the package octomap_server2 anymore. You may close this issue and open a new one on :

https://github.com/ros-navigation/navigation2/issues

https://robotics.stackexchange.com/