Hello,

At first I want to say that I am relatively new to Ros, so I am sorry if my question is trivial, but I simply couldn't find any answers on my google search (In fact I find it quite difficult in general to find useful ros documentation, so if anyone has general tips where to look at, I would highly appreciate it) I am using Ubuntu 20.04 and Ros2 foxy

Now to my problem: I am currently working on a Robot which currently uses an RPLidarA1, Realsense T265 and Realsense D435 as sensors (as well as a selfmade drive system). All of the sensors are working and deliver data. I am at the point where I can view the data thats coming in in rviz2, but I would like to not only see the current data, but I also want to see past data (I am mostly talking about the Pointcloud data of the D435 here). So I want to create a map from the data, that will be displayed in rviz2. My research showed, that most people seem to use rtabmap for that. So i installed it on my system and with the command rtabmap i can open the GUI and select my D435 and I can map the environment. But I can't use it like that when I have the node for the D435 running since the camera is already in use and also that way I wont get my data in rviz2.

I found the following command that worked for others:

ros2 launch rtabmap_launch rtabmap.launch.py 
args:="-d --Mem/UseOdomGravity true --Optimizer/GravitySigma 0.3" 
odom_topic:=/T265/odom/sample 
frame_id:=T265_link 
rgbd_sync:=true 
depth_topic:=/D435/depth/color/points  
rgb_topic:=/d435/color/image_raw 
camera_info_topic:=/D435/color/camera_info 
approx_rgbd_sync:=false 
visual_odometry:=false

but for me only delivered a window of rtabmap with nothing in it.

I hope anyone has an idea what I did wrong. If you need any more information, feel free to ask.

Best regards, Martin