Subtraction of 2 Point cloud/DSM

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deepoberai
Posts: 1
Joined: Sat Jan 07, 2023 6:04 am

Subtraction of 2 Point cloud/DSM

Post by deepoberai »

Hello,

I have few queries as below: -

1. is it possible to subtract 2 point cloud/DTM of same location/projection.
2. Can we flatten/delete a object like car, bus, tree, house etc. from the Point cloud without removing the base surface.
3. How accurate the volume estimation in CC.
4. Is slop/road gradient calculation is possible in point cloud in CC.
5. Is contour generation is possible.
6. Is surface creation is possible using triangulation method in CC
daniel
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Location: Grenoble, France
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Re: Subtraction of 2 Point cloud/DSM

Post by daniel »

That's a lot of questions...

1. The only way to do that is to use the 2.5D Volume calculation tool (https://www.cloudcompare.org/doc/wiki/i ... .5D_Volume) and then output the resulting grid (which is the difference between the 2 point clouds) with the 'Export grid as cloud' button.

2. Not sure to understand. There are options to extract the base surface (with the CSF plugin especially)...

3. The accuracy depends on the grid resolution (which also depends on your cloud density, as you won't be able to set if very high if you don't have a lot of points)

4. Maybe the 'Dip/dip direction' calculation can help?

5. Yes, with the either the 'Cross Section' or the 'Extract sections' tools (see https://www.cloudcompare.org/doc/wiki/index.php/Methods)

6. Either with Delaunay (2.5D) or with the Poisson Surface Reconstruction plugin
Daniel, CloudCompare admin
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