ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange
Ask Your Question

narf and kdtree flann search

asked 2011-07-26 02:56:53 -0500

robojoe gravatar image

updated 2014-01-28 17:10:06 -0500

ngrennan gravatar image


I'm not sure if I should ask this here or in the PCL mailing list but I'll ask here anyways.

I am trying to use kdtree_flann to match narf descriptors. I am extracting the descriptors in a similar way to the NARF PCL tutorial. The problem is when I try perform the NN search between two pointclouds (pointcloud A added as the input and point cloud B used as the query), all the features in B match to the same feature in A. The distances reported by kdtree are all 0 (zero).

  • I noticed that narf36 has a {x,y,z,roll,pitch,yaw} value which are all 0 (zero) for my features, is this why all my distances are zero when kdtree performs its search?

The .descriptor values themselves are different for each feature in A and B. I would have expected that kdtree would use the Narf::getDescriptorDistance function or something similar to compute the distances.

  • Does anyone know what distance metric it uses when you provide the PointCloud< Narf36 > as the data type to kdtree?
  • And is there a way to change this (to maybe even a custom distance function)?

Thanks in advance, - Joe

edit retag flag offensive close merge delete


You'll probably get a faster/better response on the PCL mailing list.
fergs gravatar image fergs  ( 2011-07-26 05:53:14 -0500 )edit
Also, you might get a better response if you break up your post into bullet points, and direct questions. Many people tend to pass over long paragraphs.
Asomerville gravatar image Asomerville  ( 2011-07-26 07:26:40 -0500 )edit

1 Answer

Sort by » oldest newest most voted

answered 2011-09-02 11:45:22 -0500

Mac gravatar image

The comments above are correct; this is best asked on pcl-users.

edit flag offensive delete link more

Question Tools


Asked: 2011-07-26 02:56:53 -0500

Seen: 649 times

Last updated: Sep 02 '11