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Visualiation from .pcd files - no points to read

Hello,

I want to make point of cloud from multiple files with .pcd extensions. I have installed ROS Kinetic and done steps accordingly to this tutorial. I am getting this error : [pcl::PCDReader::readHeader] No points to read

Here I have few questions:

  1. Is range image as useful as points of cloud? Or should I use other method in order to visualize it.
  2. How can I merge multiple scans from the same object (production plant from inside) to achieve final PoC.
  3. I will appreciate if someone could give me some hints/links/other materials which might be helpful and give me knowledge to handle this project.

Edit: Firstly, thanks for explaining 2 point.

Regarding proper file name, I have changed this part in code. The file is found but error as mentioned before occurs. I am doing this after I had made my project exacutable

About project - I have to visualize in 3D environment production plant. I have .bag file with messages and about 40 .pcd files with scans taken from different spots. What I've been trying to do is to visualize only one of this scan. I've got stuck on this error.

Asked by RafMil on 2018-08-23 10:58:02 UTC

Comments

Have you opened these pcd files with another viewer to confirm they are valid pcd files and they contain points? What are the file sizes? The warning message is saying the file is empty, the first thing to check is that the pcd file isn't actually empty.

Asked by PeteBlackerThe3rd on 2018-08-24 10:01:36 UTC

Yes, each files has about 1.4 MB and structure looks like: *2097 0 R/XYZ 27 413 null]>> endobj 11772 0 obj <> endobj 11773 0 obj <> endobj 11774 0 obj *

For me it looks fine.

Asked by RafMil on 2018-08-24 12:53:29 UTC

I don't recognise the file structure you show at all. An ascii pcd file should be structured as shown here. If it doesn't match this it's either a binary pcd or a different file format.

Asked by PeteBlackerThe3rd on 2018-08-25 07:42:15 UTC

Answers

Regarding your first question, how are you running the example program? You need to provide the name of a valid pcd file for this to work.

  1. If you want to visualise a point cloud you can't beat a 3D viewer which you can navigate around showing the full point cloud. Range images are good for showing a particular point of view if you have very dense points, but I wouldn't use them much myself.

  2. You'll want to look into Iterative Closest Point (ICP) there are some good tutorials on the PCL website

  3. You'll need to tell us more about you project before we can really help you with this.

Asked by PeteBlackerThe3rd on 2018-08-23 14:45:07 UTC

Comments

Thanks for your answer. It makes few topics more clear for me. Anyway, I have tried to go trough ICP tutorial (with monkey example), and while running run command $ ./interactive_icp monkey.ply 1 ./ message ./ is a directory pops up. I would like to try import .pcd into blender. Any ideas?

Asked by RafMil on 2018-08-24 12:50:28 UTC