Proper way of subsribing to a costmap_2d OccupancyGrid
Hi, I am using the costmap_2d_node to build a local costmap from a Lidar. I can view the local costmap properly in Rviz. What I don't understand is that the topic /costmap of type OccupancyGrid is only published once, no matter how high I set the value of the publish_frequency parameter. I see that there is a /costmap_updates topic of type OccupancyGridUpdate and I guess there is a proper way of subcribing to the local costmap through it but i did not find any information about it. For instance, what mechanism Rviz uses to display the live costmap?