Ros2 LIDAR data structure definition does not match data

[sebastianohl]

Describe the Bug
The lidar plugin in the webots ros2 driver outputs data as sensor_msg.pointcloud2 data structure. This data structure have an array how the binary data is structured. the plugin describes the data as 3 float values (x,y,z). Unfortunately this is not according to the webots lidar point data structure WbLidarPoint[].

Steps to Reproduce

1. mount a Sick LMS291 lidar sensor to a vehicle
2. enable ros output
3. receive pointcloud2 data in a ros2 node and try to decode it

Expected behavior
the expected behavior is that the data in described in message.fields should match the data stored in message.data. The data described by the datastructure WbLidarPoint (https://cyberbotics.com/doc/reference/lidar?tab-language=c). It does not only contain x,y,z as floats but also the layer (int32) and the time(float32). This need to be added to the fields array.

Affected Packages
List of affected packages:

• webots_ros2_driver

System

• Webots Version: R2022a
• ROS Version: galactic
• Operating System: Ubuntu 20.04
• Graphics Card: vmware

[omichel]

@ad-daniel: was this issue fully addressed in #4545? If so, can we close it?

[ad-daniel]

Not yet, only on the ROS1 side at the moment