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Export mesh as shapefile

Posted: Fri Apr 21, 2023 3:26 pm
by courtlea
Hello there,
I use point clouds that have been acquired over several years by TLS and that represent a rock wall in the Mont Blanc massif.
I try to quantify the erosion rate of this wall by modelling the blocks that detached from one year to another (notably thanks to the visualization tool M3C2) and by studying the volumes involved.
To do this, I cut the point clouds where the blocks have been detached and, after some manoeuvres and the "PoissonRecon" plugin, I manage to obtain a mesh of the missing block.
I would like to export this mesh in shapefile format to integrate it into a QGIS project and wonder if this is possible.
If not, would you have an alternative solution for me?

I don't know if what I'm saying is clear but I hope it is!

Thanks a lot in advance.
Regards,

Re: Export mesh as shapefile

Posted: Sat Apr 22, 2023 8:26 pm
by daniel
Well, theoretically (or at least when I look at the code), CC should be able to export a mesh as a SHP file. Have you tried? If yes, were you able to load it in QGIS?

Re: Export mesh as shapefile

Posted: Sun Apr 23, 2023 11:17 pm
by DA523
CC exports pointscloud into shp and fails to export mesh into shp

Re: Export mesh as shapefile

Posted: Mon Apr 24, 2023 7:18 am
by courtlea
As DA523 said, I can export the pointscloud into a shapefile and load it in QGIS but not the mesh. I have the following error message: "An error occurred while saving 'E:[name_of_the_mesh.shp]': incompatible entity/file types".

Re: Export mesh as shapefile

Posted: Mon Apr 24, 2023 8:52 pm
by daniel
Hum, interesting, I'll have to take a look at this!

Re: Export mesh as shapefile

Posted: Mon Apr 24, 2023 9:05 pm
by daniel
Ah ok, that's because to be to a SHP file, a mesh has to be organized in a very specific way: either as a fan, or as a triangle strip (see https://downloads.esri.com/support/whit ... y_Type.pdf).

CC has no other choice than testing if the mesh respects this condition before saving it to SHP file... I'll try to issue a clearer error message.

Re: Export mesh as shapefile

Posted: Thu Feb 15, 2024 5:01 am
by SAYURI
Hello,

I do not understand English. I rely on translation sites.
I would like to display mesh data created from a point cloud in QGIS.
An error occurs when saving a mesh created with PoissonRecon using shp.

An error occurred while saving PASS/Mesh[ground2.shp': incompatible entity/file types

Is it a problem with Compute normals, PoissonRecon parameters?
I don't understand the special way to organize it.

Please give me some guidance.

Re: Export mesh as shapefile

Posted: Thu Feb 15, 2024 7:21 am
by daniel
To what file format are you trying to export the mesh to?

SHP won't work, and it doesn't look like QGis is supporting any standard '3D' mesh format (see https://docs.qgis.org/3.4/en/docs/user_ ... rties.html).

Re: Export mesh as shapefile

Posted: Thu Feb 15, 2024 7:51 am
by SAYURI
Hello,

I selected SHP entity(*.shp) to save the file.
And the error mentioned in the question occurred.

>SHP won't work
I recognized it.

>it doesn't look like QGis is supporting any standard '3D' mesh format
exactly. So I tried to convert the mesh data to shp.

Does the file save SHP entity (*.shp) mean mesh format?
I'm immature. I may be saying something strange.

I'll think of another way. Thank you very much for your prompt reply.

Re: Export mesh as shapefile

Posted: Thu Feb 15, 2024 8:11 am
by daniel
Ok, so I checked in the code and you can save meshes to SHP files.

Which entity have you selected before use the 'File > Save' option? Make sure to select a mesh entity in the DB tree.