warning in terminal

[7DoF]

Hi, when i run the launch file I get this message in the terminal indefinitely:
Failed to find match for field 'ring'.

Here's the info about my rosbag:

path:        calib_3.bag
version:     2.0
duration:    1:06s (66s)
start:       Jul 19 2023 15:15:13.51 (1689759913.51)
end:         Jul 19 2023 15:16:19.87 (1689759979.87)
size:        1007.3 MB
messages:    35466
compression: none [664/664 chunks]
types:       sensor_msgs/Imu         [6a62c6daae103f4ff57a132d6f95cec2]
             sensor_msgs/PointCloud2 [1158d486dd51d683ce2f1be655c3c181]
topics:      /imu0               33284 msgs    : sensor_msgs/Imu        
             /mavros/imu/data     1519 msgs    : sensor_msgs/Imu        
             /ouster_11/points     663 msgs    : sensor_msgs/PointCloud2

Thanks

[nkhedekar]

The point type for your pointcloud may be different from what is expected by this package. I would check the point fields in the pointcloud2 message and match them with the point types defined here

LiDAR_IMU_Init/src/preprocess.h

Lines 35 to 115 in 6d20db3

	namespace velodyne_ros {
	struct EIGEN_ALIGN16 Point {
	PCL_ADD_POINT4D;
	float intensity;
	float time;
	uint16_t ring;
	EIGEN_MAKE_ALIGNED_OPERATOR_NEW
	};
	} // namespace velodyne_ros
	POINT_CLOUD_REGISTER_POINT_STRUCT(velodyne_ros::Point,
	(float, x, x)
	(float, y, y)
	(float, z, z)
	(float, intensity, intensity)
	(float, time, time)
	(uint16_t, ring, ring)
	)
	namespace ouster_ros {
	struct EIGEN_ALIGN16 Point {
	PCL_ADD_POINT4D;
	float intensity;
	uint32_t t;
	uint16_t reflectivity;
	uint8_t ring;
	uint16_t ambient;
	uint32_t range;
	EIGEN_MAKE_ALIGNED_OPERATOR_NEW
	};
	} // namespace ouster_ros
	POINT_CLOUD_REGISTER_POINT_STRUCT(ouster_ros::Point,
	(float, x, x)
	(float, y, y)
	(float, z, z)
	(float, intensity, intensity)
	// use std::uint32_t to avoid conflicting with pcl::uint32_t
	(std::uint32_t, t, t)
	(std::uint16_t, reflectivity, reflectivity)
	(std::uint8_t, ring, ring)
	(std::uint16_t, ambient, ambient)
	(std::uint32_t, range, range)
	)
	// namespace pandar_ros
	namespace pandar_ros {
	struct EIGEN_ALIGN16 Point {
	PCL_ADD_POINT4D;
	float intensity;
	double timestamp;
	uint16_t ring;
	EIGEN_MAKE_ALIGNED_OPERATOR_NEW
	};
	}
	POINT_CLOUD_REGISTER_POINT_STRUCT(pandar_ros::Point,
	(float, x, x)
	(float, y, y)
	(float, z, z)
	(float, intensity, intensity)
	(double, timestamp, timestamp)
	(std::uint16_t, ring, ring)
	)
	//ANCHOR robosense modify
	namespace robosense_ros {
	struct EIGEN_ALIGN16 Point {
	PCL_ADD_POINT4D;
	std::uint8_t intensity;
	std::uint16_t ring;
	double timestamp;
	EIGEN_MAKE_ALIGNED_OPERATOR_NEW
	};
	}
	// namespace robosense_ros
	POINT_CLOUD_REGISTER_POINT_STRUCT(robosense_ros::Point,
	(float, x, x)
	(float, y, y)
	(float, z, z)
	// use std::uint32_t to avoid conflicting with pcl::uint32_t
	(std::uint8_t, intensity, intensity)
	(std::uint16_t, ring, ring)
	(double, timestamp, timestamp)

Most likely the datatype for the ring field is different (e.g. the bag as the ring as a uint8 instead of a uint16) in which case you can just make the change in these lines.

[Vor-Art]

I have simular warning:

Failed to find match for field 'reflectivity'. 
Failed to find match for field 'ring'. 
Failed to find match for field 'ambient'. 
Failed to find match for field 'range'.

These warnings occur due to the specifics of different lidar data.
You need to look at the data header and figure out which fields you have.

I handle this warning this way:

1. Collect some of the lidar data

   rostopic echo /os1_points > test_lidar.txt
   

2. Display header of one message:

   $ head test_lidar.txt -n42
   header: 
     seq: 5
     stamp: 
       secs: 1565943694
       nsecs: 928035526
     frame_id: "ouster"
   height: 1
   width: 65537
   fields: 
     - 
       name: "x"
       offset: 0
       datatype: 7
       count: 1
     - 
       name: "y"
       offset: 4
       datatype: 7
       count: 1
     - 
       name: "z"
       offset: 8
       datatype: 7
       count: 1
     - 
       name: "intensity"
       offset: 16
       datatype: 7
       count: 1
     - 
       name: "t"
       offset: 20
       datatype: 6
       count: 1
     - 
       name: "ring"
       offset: 24
       datatype: 5
       count: 1
   is_bigendian: False
   point_step: 32
   row_step: 2097184
   data: [.......]
   is_dense: True
   ---
   

3. Update preprocess.h file:

   You can check the docks to choose the right fuild types: sensor_msgs/PointField and sensor_msgs/PointCloud2
   

4. Rebuild project: catkin build