Obstacle layer don't subscribe laser scans

[PSotiriadis]

Hi
I want to report an issue with nav2_costmap_2d package. Using navigation2 with ROS2 Humble, local costmap is not indicated in RViz, like in screenshot below:

However, global costmap is working properly:

So I thought that problem can be in obstacle layer and I took a look in navigation2->nav2_costmap_2d->plugins->obstacle_layer.cpp. I realized, that in line 226, we unsubscribe the laser scan subscriber, which is subscribed above in lines 224,225. I comment line 226 and local costmap is working now fine for me and is indicated in RViz normally:

This is logical for me, but I don't know if it is desired from the authors of navigation2 (maybe it is desired to unsubscribe in this position, but forgot to subscribe later). I want only to highlight the problem!!!

PS: Same happens also later in line 255, where PointCloud2 subscriber is unsubscribed, but I didn't check if works or not. Please see also this position, because it can also produce a problem.

[padhupradheep]

Already reported #3014 ! More info #3018

More info here https://discourse.ros.org/t/nav2-issues-with-humble-binaries-due-to-fast-dds-rmw-regression/26128/2

switch to cyclone dds and it works good

[SteveMacenski]

Indeed, working through it with Fast-DDS, but there’s the temp PR patch that can be applied to work with Fast-DDS if absolutely required, but I’d recommend just using Cyclone. Fast-DDS has a number of other issues at the moment as well.

[PSotiriadis]

First, @SteveMacenski & @padhupradheep thanks a lot for the very fast response and sorry for the repetition of this issue. I switch to cyclone dds and everything works!!!