# Substract meshes
**URL:** https://community.freefem.org/t/substract-meshes/2063
**Category:** General Discussion
**Created:** [October 15, 2022, 5:30am UTC](https://community.freefem.org/t/substract-meshes/2063 "2022-10-15T05:30:18Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@galfras](https://community.freefem.org/u/galfras)
#### Post date: [October 15, 2022, 5:30am UTC](https://community.freefem.org/t/substract-meshes/2063/1 "2022-10-15T05:30:18Z")
Hello!
I have two already constructed meshes and I what to substract one from the other (make a hole in the bigger mesh with the shape of the smaller mesh). Is that possible?
Thanks!
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### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [October 15, 2022, 5:58am UTC](https://community.freefem.org/t/substract-meshes/2063/2 "2022-10-15T05:58:28Z")
Use the `trunc` function.
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### Author:  [@galfras](https://community.freefem.org/u/galfras)
#### Post date: [October 15, 2022, 5:00pm UTC](https://community.freefem.org/t/substract-meshes/2063/3 "2022-10-15T17:00:17Z")
I read a lot about the Trunc function, but I could’t figure it out how give two meshes as parameters. Before asking I tried something like:
mesh Th = trunc(Th0, Sh);
Where Th0 is the bigger mesh and Sh the smaller mesh. I couldn’t make it work.
NOTE: I’m working with 2D meshes
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### Author:  [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [October 16, 2022, 10:08am UTC](https://community.freefem.org/t/substract-meshes/2063/4 "2022-10-16T10:08:37Z")
THe problem is not so simple, to remove a part of the mesh inside other mesh.
To day in freefem++, the only way in build a mesh from all the boundary, by hand, and than use trunc of remove some part!