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Labeling each point in the point cloud

Posted: Thu Apr 09, 2020 8:26 am
by dhirajsuvarna
Hi,

Thank you for this Software, it is really amazing.

I am new to this software and here is what I am trying to achieve.

I am looking to label each point in the point cloud with a label and then export the point cloud in ascii format.
Ideally this would be stored as follows -
X Y Z Label

I tried using "Point Picking" feature, where I am able to label group of points using "Rectangular 2D Label", but when I try to save it into an ascii format the label information is not saved.

I would really appreciated any help on this front.

Re: Labeling each point in the point cloud

Posted: Thu Apr 09, 2020 4:52 pm
by daniel
Ah! Interesting idea, but sadly CloudCompare doesn't support labels this way, or even exporting labels.

We just added recently the ability to create labels from an ASCII file with a column with text labels. But they are created as separate "2D label" entities and are not considered at export time.

Re: Labeling each point in the point cloud

Posted: Thu Apr 09, 2020 4:55 pm
by daniel
Here is a dirty hack:

One thing you could do is creating a scalar field instead. You can cut the cloud in multiple parts (with the scissors tool). Then 'add' a constant scalar field to each of them with 'Edit > Scalar fields > Add constant SF' (use a specific value for each one and make sure the scalar field name is always the same). Eventually merge all the parts together.

Export the cloud to ASCII. The ASCII file will have a column with all the values you set. You can then replace them by a text label with any smart text editor (e.g. Notepad++).

Re: Labeling each point in the point cloud

Posted: Sat Apr 11, 2020 4:17 am
by dhirajsuvarna
Thanks for the hack Daniel,

I did try it out, and I am able to get the scalar values for each point.
But sadly, I am not able to read these scalar values using Open3d library or Point Cloud Library (python libs).
Hence for now, as a workaround I am thinking of using the color values to distinguish points.

Let me know if there is any other idea you got or also if you are planning to include this feature in the future release.