Align two clouds in a small overlapping area

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Mauro Marty
Posts: 3
Joined: Wed Dec 05, 2012 11:45 am

Align two clouds in a small overlapping area

Post by Mauro Marty »

Hello,

I`ve two point clouds representing a mountainous area. They`re overlapping in a small area. They both have the same reference system and scale, but originate from different sources (one is an aereal laser scan, the othe a terrestrial laser scan)
I want to align the overlapping area, because there might be some horizontal shift between the clouds because of orientation differences of the scanners during record.

Does anyone know whether this is possible?

Thanks for any information.

Mauro
daniel
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Re: Align two clouds in a small overlapping area

Post by daniel »

Good question, I've just created an entry in the wiki for this:
http://www.cloudcompare.org/doc/wiki/in ... ing_clouds

This is the only way to apply the ICP registration algorithm on a subset of a point cloud for now...
Daniel, CloudCompare admin
Mauro Marty
Posts: 3
Joined: Wed Dec 05, 2012 11:45 am

Re: Align two clouds in a small overlapping area

Post by Mauro Marty »

Thanks Daniel for the fast answer.

I think your advise worked out. But how do I see, that the applied transformation has finished and how do I export the transformed cloud? I guess I have to keep the transformed point cloud activated and save it as whatever file I want to, is this correct?

And I suppose my original data cloud doesn`t get physically transformed, that means my original .las files I first loaded in CC stay unchanged?

Thanks,


Mauro
daniel
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Re: Align two clouds in a small overlapping area

Post by daniel »

I'm not sure about your question 'how do I see that the applied transformation has finished'? The 'Apply transformation' tool is immediate (once you hit "ok", your selected cloud - should be the original one - will be rotated/translated).

Then you keep this cloud selected, and you can "save" it (with the 'File > Save' entry). Be sure to select the cloud itself (and not its container).

Otherwise you are correct, the original (LAS) file will remained unchanged. Once a cloud is loaded, data is kept in memory and the input file is closed and "forgotten".
Daniel, CloudCompare admin
Mauro Marty
Posts: 3
Joined: Wed Dec 05, 2012 11:45 am

Re: Align two clouds in a small overlapping area

Post by Mauro Marty »

Thank you daniel,

exactly the advise I needed.

Mauro
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