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ros-drivers / velodyne

ROS support for Velodyne 3D LIDARs
http://ros.org/wiki/velodyne
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Question: How can I convert pointcould2 to XYZIR? #486

Closed horita-J closed 1 year ago

horita-J commented 1 year ago

OS and Version: ubuntu 22.04 ROS Version: ROS2 humble

I'm a beginner. I don't know how to convert pointcloud2 to ring data in ROS2 humble. In ROS1, I could use the type "velodyne_pointcloud::PointXYZIR" to take ring data, however, I couldn't use it in ROS2. Is there any methods to take ring data from pointcoud2?

I would appriciate it if you could teach me in detail about procdures.

JWhitleyWork commented 1 year ago

@horita-J On the ros2 branch, the point cloud is stored in the format PointXYZIRT which contains fields for the X, Y, and Z position as well as Intensity, Ring, and Time. The type that you're referring to in ROS1 was based on a PCL structure but the ROS2 driver avoids using PCL to remove a very heavy dependency. For iterating over the points and getting the Ring field, I recommend taking a look at the PointCloud2Iterator which can be found in sensor_msgs here. Please let me know if this resolves the issue.

horita-J commented 1 year ago

@JWhitleyWork Thank you for your reply. I could get the ring data !!