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What's the meaning of sensor_msgs/PointCloud2

asked 2016-08-04 21:45:58 -0500

iROS
3 ●1 ●3 ●3

Recently, I'm using VLP-16 to get point cloud data. But I am really confused about the structure of sensor_msgs/PointCloud2. I used the commend $ rostopic echo /velodyne_points to check the data. I have known that 32 numbers are used to describe a point. But how to transform these numbers to x, y, z coordinate of the points ? Thanks.

For example: 164, 129, 148, 191, 79, 29, 4, 191, 114, 146, 181, 188, 1, 0, 0, 0, 0, 0, 128, 63, 7, 0, 0, 0, 70, 88, 8, 112, 61, 127, 0, 0, 163, 248, 106, 191, 20, 9, 209, 190, 228, 208, 137, 62, 1, 0, 0, 0, 0, 0, 0, 64, 15, 0, 0, 0, 70, 88, 8, 112, 61, 127, 0, 0, 226, 211, 151, 191, 178, 208, 6, 191, 65, 147, 185, 60, 1, 0, 0, 0, 0, 0, 176, 66, 8, 0, 0, 0, 70, 88, 8, 112, 61, 127, 0, 0,

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I am facing the same problem, could you tell me how that structure works? Thanks!

z1huo ( 2018-08-18 11:57:38 -0500 )edit

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answered 2016-08-08 02:07:51 -0500

tfoote

58457 ●128 ●550 ●526 http://www.ros.org/

updated 2016-08-08 13:11:36 -0500

The PointCloud2 message is defined here: http://docs.ros.org/api/sensor_msgs/h...

For interacting with PointClouds it's common to use the PCL datatype: http://wiki.ros.org/pcl_ros You can subscribe and publish directly as a PCL datatype using pcl_ros/point_cloud.h

There are also a couple of iterators defined in sensor_msgs to allow access to the PointCloud2 message without the added dependency on pcl: http://docs.ros.org/api/sensor_msgs/h...