Export points coordinates picked for 2 clouds alignment

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Pierre-emmanuel
Posts: 2
Joined: Thu Apr 04, 2019 8:40 am

Export points coordinates picked for 2 clouds alignment

Post by Pierre-emmanuel »

Hi everyone,

I use CC 2.10.2 on macos 10.14 in order to registrate 2 clouds of points. I first need to do a rough alignment by points picking alignment before running the ICP registration.

I would like to know if the first step, the manual points picking, has an effect on the final registration? If yes (that I suspect) I wanted to measure its variability with several observators registering the same 2 clouds of points, diverging only by the manual picking.

To do so, does someone know if we can export the points coordinates in order to test inter/ intra observator variability? I couldn't find a way to do so...

Please find attached a screenshot showing the case, I can't even copy/paste the coordinates, is it possible on Windows/other OS? Image

Thank's a lot!
Attachments
Point picking registration
Point picking registration
Capture d’écran 2019-04-05 à 14.03.29.png (445.62 KiB) Viewed 844 times
daniel
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Re: Export points coordinates picked for 2 clouds alignment

Post by daniel »

Nope you can't export them currently (you would have to hack the code to do that).

And I don't expect a big variability, as the ICP algorithm should more or less converge to the (almost) same position as long as the rough registration is not too bad.

Mind also that with the default parameters of the ICP algorithm you'll always have some variability (even from the exact same starting position) as points are randomly selected at each iteration (to speed up the process). You can prevent that by changing the 'random sampling limit' parameter to something bigger than the clouds size).
Daniel, CloudCompare admin
Pierre-emmanuel
Posts: 2
Joined: Thu Apr 04, 2019 8:40 am

Re: Export points coordinates picked for 2 clouds alignment

Post by Pierre-emmanuel »

Thank you very much for your quick and detailed answer!

Have a nice sunday!
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