Right way to replay laser scan from bag file and visualize in rviz
I recorded a rosbag containing laser scans and while trying to play it back and visualize the output in rviz I get the following warning: Detected jump back in time of 1.0252e-05s. Clearing TF buffer.
The jump-back time just keeps increasing. I realize this problem has something to do with using the --clock option in rosbag play and using use_sim_time. Both of which are rightly done. I set at the very beginning of the launch file:
<param name="/use_sim_time" type="bool" value="true"/>
and pass the --clock option to rosbag play. I still get the warning.
The scans are being visualized in rviz, but every now and then there is a flicker in the screen and the scans go away and then come back. This is surely not how it's normally supposed to behave. (Additionally, when I feed the rosbag laser scans and other sensor data to a SLAM algorithm, it doesn't work. While in fact, the rosbag was recorded the first time with said algorithm, rtabmap).
Edit: Adding the launch file and a snippet of what the rosbag file contains:
<launch>
<param name="/use_sim_time" type="bool" value="true"/>
<node pkg="rosbag" type="play" name="playback_vel_rtab"
args="--clock $(find my_pkg)/datacapture/bagname.bag">
<remap from="/scan" to="/fake_scan"/>
</node>
</launch>
And here is my bagfile:
path: rtab_in_2023-01-27-10-05.bag
version: 2.0
duration: 2:22s (142s)
start: Jan 01 1970 01:00:00.29 (0.29)
end: Jan 01 1970 01:02:23.02 (143.02)
size: 6.2 GB
messages: 159462
compression: none [919/919 chunks]
types: nav_msgs/Odometry [cd5e73d190d741a2f92e81eda573aca7]
rosgraph_msgs/Clock [a9c97c1d230cfc112e270351a944ee47]
sensor_msgs/CameraInfo [c9a58c1b0b154e0e6da7578cb991d214]
sensor_msgs/Image [060021388200f6f0f447d0fcd9c64743]
sensor_msgs/LaserScan [90c7ef2dc6895d81024acba2ac42f369]
tf2_msgs/TFMessage [94810edda583a504dfda3829e70d7eec]
topics: /camera/depth/image_raw 459 msgs : sensor_msgs/Image
/camera/rgb/camera_info 459 msgs : sensor_msgs/CameraInfo
/camera/rgb/image_raw 459 msgs : sensor_msgs/Image
/clock 141763 msgs : rosgraph_msgs/Clock
/odom 4274 msgs : nav_msgs/Odometry
/scan 712 msgs : sensor_msgs/LaserScan
/tf 11335 msgs : tf2_msgs/TFMessage (3 connections)
/tf_static 1 msg : tf2_msgs/TFMessage
Is it possible you have two sources publishing to /clock topic? It won't work if both gazebo and rosbag are publishing the ros time.
No, it is only the rosbag that is publishing. Let me update the question with my launch file and a snippet of my rosbag file^^
When the bag file was created, it recorded the /clock topic; this is a problem because I believe that the
--clockoption synthesizes (i.e. generates) a ros clock. So your play command is sending two different data streams to the /clock topic. I would try specifying the topics you want rosbag to play back, and make sure not to publish the /clock topic from the bag file.You are right. This works like a charm (with the exception of occasionally getting the
TF_REPEATED_DATAwarning, which i think is a different issue altogether).Thanks a lot. You can write this as an answer and I will mark it as accepted.