Add Support for Default Namespace Assignment in SDF Labels for Multi-Robot Simulations

[LihanChen2004]

Feature Request

Currently, the plugin requires specifying both the SDF labels <topic> and <frame>. If these labels are not provided, the plugin logs the following error messages:

[Err] [Lidar.cc:51] No 'topic' parameter specified for the RGL lidar. Disabling plugin.
[Err] [Lidar.cc:56] No 'frame' parameter specified for the RGL lidar. Disabling plugin.

In Gazebo Ignition, these labels correspond to <ignition_frame_id> and <topic>. If they are omitted from the SDF file, Gazebo automatically assigns them as /<world_name>/model/<link_1>/<link_2>/.... For instance, using the gpu_lidar plugin without specifying these labels results in:

frame_id: /world/default/model/robot/link/right_mid360/sensor/right_mid360_lidar
topic: /world/default/model/robot/link/right_mid360/sensor/right_mid360_lidar/scan/points

This automatic namespace assignment is crucial for multi-robot simulations, as it simplifies the configuration process.

I am willing to address this issue. Please let me know your thoughts.

[PawelLiberadzki]

Hi @LihanChen2004, thank you for your analysis! This sounds reasonable and will in fact simplify the process - I see no downsides. We will be grateful if you will address this issue.