Noise on .las files

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ayush
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Joined: Sat Nov 19, 2022 1:19 am

Noise on .las files

Post by ayush »

Hi, I am trying to open UAV generated dense point cloud in CC but getting a lot of noise at the z-axis. If I use top and bottom-facing icons for my point cloud, it looks fine, but as I moved to the other directions, it scattered. I wonder if there is something wrong with what I am doing.
daniel
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Re: Noise on .las files

Post by daniel »

Well, there are 2 options: either the cloud is noisy, or you have kept the large coordinates (if any) which is generally a bad idea as OpenGL can't properly display them (hence it generally causes a noisy display).
Daniel, CloudCompare admin
ayush
Posts: 3
Joined: Sat Nov 19, 2022 1:19 am

Re: Noise on .las files

Post by ayush »

Thank you, Daniel!
But still, I am not able to solve the problem. I wanted to share more insights for a better understanding. The first image is the top angle for the .las data, where the second is scattering; my concern is also about the zoom-in level. Can you suggest any document or video I can watch for this?
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daniel
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Re: Noise on .las files

Post by daniel »

The scale of the cloud seems indeed very small... Where does it come from?

Would you be able to share it with me maybe? (admin [at] cloudcompare.org)
Daniel, CloudCompare admin
ayush
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Joined: Sat Nov 19, 2022 1:19 am

Re: Noise on .las files

Post by ayush »

daniel wrote: Mon Nov 21, 2022 8:32 am The scale of the cloud seems indeed very small... Where does it come from?
It came from the Drone with the Multispectral sensor dense point cloud.

Would you be able to share it with me maybe? (admin [at] cloudcompare.org)
I did share data with admin@cloudcomare.org; I hope you can address the query.
daniel
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Joined: Wed Oct 13, 2010 7:34 am
Location: Grenoble, France
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Re: Noise on .las files

Post by daniel »

Thanks. I believe the issue is simply that the cloud has geographical coordinates (with X and Y being angles) and not cartesian coordinates (all the same units). CC doesn't manage this mix of very small angles values for X and Y, and large coordinates for Z (relatively).
Daniel, CloudCompare admin
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