# Remove elements from a region

**URL:** https://community.freefem.org/t/remove-elements-from-a-region/2140
**Category:** General Discussion
**Created:** [November 23, 2022, 2:05pm UTC](https://community.freefem.org/t/remove-elements-from-a-region/2140 "2022-11-23T14:05:31Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![agTSL](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@agTSL](https://community.freefem.org/u/agTSL)
#### Post date: [November 23, 2022, 2:05pm UTC](https://community.freefem.org/t/remove-elements-from-a-region/2140/1 "2022-11-23T14:05:31Z")

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Hello,

I would like in a 3D mesh remove elements which are in a specific region.  
Regions doesn’t have commom boundary and I can not use trunc fonction with geometrical criteria.  
Are there a possibility with functions “movemesh”, “trunc”, … to select a tetreadre with his region number?  
Or perhaps with tetgen but I didn’t find it.

Best Regards,  
Alexandre

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<div class="post-metadata">

### Author: ![agTSL](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@agTSL](https://community.freefem.org/u/agTSL)
#### Post date: [November 24, 2022, 2:36pm UTC](https://community.freefem.org/t/remove-elements-from-a-region/2140/2 "2022-11-24T14:36:56Z")

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I find a solution, not very beautiful but it’s work…

1. load my mesh with n region with freefem
2. export a vtk file (savevtk)
3. read the vtk file with paraview, use threshold filter to extract region and export vtk file
4. load the vtk file in freefem (vtkload3)

If someone have a solution with a function in freefem I am still interested. Thank you
