DEM

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Sile
Posts: 21
Joined: Tue Oct 10, 2017 3:40 pm

Re: DEM

Post by Sile »

These are my trees that I have projected. The lowest point of each tree are at the same level (Z coordinate), but the points that make up the tree have been stretched in the Z direction. I believe all my settings are correct. I will have to play with it some more. I was just wondering if you have seen this problem before?
daniel
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Re: DEM

Post by daniel »

Nope, never. The stretching is really suspicious.
Daniel, CloudCompare admin
wpqjbzwm
Posts: 37
Joined: Tue May 24, 2016 10:59 am

Re: DEM

Post by wpqjbzwm »

hi, Sile. You may try plugin CSF to get ground and non-ground points, and then use the method provided by Daniel. You can refer to our post at Researchgate:
How to calculate AGL (above ground level) height using CSF in Cloudcompare
Sile
Posts: 21
Joined: Tue Oct 10, 2017 3:40 pm

Re: DEM

Post by Sile »

Hello wpqjbzwm,

I have used the plugin CSF. Separating the ground points and non-ground points is not the issue. As you can see in my other posts, the issue is my trees are being stretched. When I view the "side view" there are multiple sections of points on a z coordinate. All of these are put together resulting in my stretch tree.

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daniel
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Re: DEM

Post by daniel »

I still don't see how this is possible... are you sure the cloud vertical dimension is right (i.e. parallel to Z)?

If you can't send me the dataset, could you maybe make a video of your process so that we could spot a potential mistake?
Daniel, CloudCompare admin
Sile
Posts: 21
Joined: Tue Oct 10, 2017 3:40 pm

Re: DEM

Post by Sile »

Daniel,

I will ask my professor if that is alright to do, since it is not my data. If he agrees, I will be able to post the video tomorrow.
Sile
Posts: 21
Joined: Tue Oct 10, 2017 3:40 pm

Re: DEM

Post by Sile »

My professor has allowed me to share a sub sample plot of the data with you. How do you want me to send it to you?
daniel
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Re: DEM

Post by daniel »

You can send me the data directly by email or via a file sharing website (dropbox, google drive, etc.) : cloudcompare [at] danielgm.net
Daniel, CloudCompare admin
daniel
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Re: DEM

Post by daniel »

Thanks for the dataset.

I tested the method I described earlier and I couldn't reproduce your result:
- load the cloud
- start the Rasterize tool
- make sure the projection direction is 'Z'
- set the grid 'step' to something not too small (I used 0.1 or 0.2 during my tests)
- make sure the 'height range' checkbox in the 'Export' section is checked
- click on the 'Cloud' button in the same 'Export' section
- close the Rasterize tool
- select the generated 'raster' (cloud)
- change the active scalar field to 'Height range' (see the cloud properties)
- call 'Edit > Scalar fields > Set SF as coordinates'
- click on the 'magnifier' icon to center the camera on the cloud (as its coordinates may have changed a lot)

Here's what I get:
cc_height_range.JPG
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Daniel, CloudCompare admin
Sile
Posts: 21
Joined: Tue Oct 10, 2017 3:40 pm

Re: DEM

Post by Sile »

Daniel,

That worked perfectly. The problem I believe I was having was not having the correct Active field selected. Thank you so much for working with me on this problem and I hope others find it useful as well. Cheers!
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