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Export multiple selections as PLYs

Posted: Thu Dec 15, 2022 6:08 am
by Evan
Hi Daniel,

I noticed that if I select multiple clouds and try to export, the option for PLY export vanishes. I can do bin, ASCII Cloud, e57, dxf, shp, and pov.

I see that there is very little difference between PLY and space separated ASCII. Really the only difference is in the header. I am using the PCV tool in Blender which requires PLY files if I want to load in a sequence of point clouds. Unfortunately it doesn't like the ASCII files, with and without headers, even if I save with the .ply extension. I think it may be looking for "ply" on the first line.

I have 75 point clouds from an Azure Kinect recording loaded into CloudCompare which I cleaned and clipped. I now need to re-export these as PLYs. Is there any functionality in the GUI to do this without exporting one by one? Maybe with the command line or with Python? I guess I can figure out how to add a fake header to the ASCII files to trick PCV in Blender, but I was hoping for something quicker.

Thanks.

Re: Export multiple selections as PLYs

Posted: Fri Dec 16, 2022 3:26 pm
by JoeKan
I think the EXPORT option works on only one cloud at a time (as I do not think there is a provision in the exporter to do multiple export instances). This had me stymied for a while as well.

The way I solved it is that I made copies of the clouds, and then joined all the copies into one overall cloud. I then exported that.
Use the "Edit"=>"Merge" commands to merge the clouds together.
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Re: Export multiple selections as PLYs

Posted: Fri Dec 16, 2022 9:39 pm
by Evan
Hi Joe,

Thanks for your reply! My issue is that I need the point clouds exported separately. They depict frames from a dynamic recording, i.e., it isn't capturing the same static scene. This was output from Microsoft's Azure Kinect, which provides such data. I have 75 frames (point clouds) that I'm trying to export.

Re: Export multiple selections as PLYs

Posted: Sat Dec 17, 2022 8:14 am
by daniel
The PLY format (as many other formats) doesn't allow to store multiple clouds in a single file.

That's why if you select multiple files, CC will only allow you to select the formats that can handle that. And mind that there's an exception for ASCII files. Even though they can't store multiple clouds at once, CC is simply able to generate one file per cloud automatically.