filter close range in-air noise with Azure kinect ROS

[simon]

Good day!
I've set up the Azure kinect depth camera within ROS (melodic, ubuntu 18.04) and got some amazing results. But I also encountered some issue about close range airborne noise points (shown below).
I've been trying to get rid of the close range points to make a better map but couldn't find the correct way to adjust RTAB-map. What I need is a real-time pointcloud2 ROS topic with rgbd data to stream to Unity (can cutoff the close range points in database viewer). I've tried to modify launch file, using "rosparam" to set several params, but still no luck. Pretty sure there are some parameters can solve this problem but I just haven't find it yet. Please help~
Thousand thanks!

[matlabbe]

Which is the topic exactly you want to filter? For cloud_map, you could set Grid/RangeMin

cheers,
Mathieu

[simon]

Hi Mathieu,
cloud_map is ideal for the result, and I just tried to set this parameter in the launch file and also with rosparam, but it still didn't work. I must have done it wrong.... And I noticed this Grid/RangeMin always reset to 0.0 when I launch.
I'm still not very clear of the way how these nodes work together,,, is it possible for me to change this parameter inside a config file? I couldn't find a corresponding one (seems config.ini) inside "Documents", or "/opt/ros/melodic/share/rtabmap_ros/launch/config/". Please help~

Thank you very much!

[matlabbe]

The parameter is not set at the right place. If you modify rtabmap.launch, set it under rtabmap node here:

<param name="Grid/RangeMin" value="5"/>

The more general way I use with rtabmap.launch is to do:

roslaunch rtabmap_ros rtabmap.launch args:="-d --Grid/RangeMin 5"

When you change a parameter with "rosparam set" after the node has been launched, you should call "update_parameters" service of rtabmap node so that rtabmap knows it needs to re-read the parameters.

cheers,
Mathieu

[simon]

Hi Mathieu,
Problem solved! It's really nice and efficient to have knowledgeable people like you to help us newbies. Thank you again and have a nice day!