# Feature Request: create nset from elset

**URL:** <https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216>\
**Category:** Uncategorized\
**Created:** [April 16, 2024, 7:11am UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216 "2024-04-16T07:11:16Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![Kankreu](https://avatars.discourse-cdn.com/v4/letter/k/7ba0ec/32.png) [@Kankreu](https://calculix.discourse.group/u/Kankreu)\
**Post date:** [April 16, 2024, 7:11am UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216/1 "2024-04-16T07:11:16Z")

</div>

hello all,  
I was cross checking the documentation of Calculix and Abaqus and came across something I miss:  
I’m generating a mesh from gmsh and it created all surfaces as elset.  
I need to clamp one of them so I used:  
\*NSET,NSET=clamp,ELSET=Surface9

Unfortunately, this is not supported today.

Thanks,  
Max

---

<div class="post-metadata">

**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\
**Post date:** [April 16, 2024, 8:26am UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216/2 "2024-04-16T08:26:33Z")

</div>

Yeah, you could create a feature request on GitHub: [Issues · Dhondtguido/CalculiX · GitHub](https://github.com/Dhondtguido/CalculiX/issues)

---

<div class="post-metadata">

**Author:** ![Kankreu](https://avatars.discourse-cdn.com/v4/letter/k/7ba0ec/32.png) [@Kankreu](https://calculix.discourse.group/u/Kankreu)\
**Post date:** [April 16, 2024, 9:19am UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216/3 "2024-04-16T09:19:44Z")

</div>

Thanks for the suggestion. I was looking for a place for FR and couldn’t find it.  
I probably didn’t search well enough 🙂

---

<div class="post-metadata">

**Author:** ![Nobody-86](https://avatars.discourse-cdn.com/v4/letter/n/e495f1/32.png) [@Nobody-86](https://calculix.discourse.group/u/Nobody-86)\
**Post date:** [April 16, 2024, 8:25pm UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216/4 "2024-04-16T20:25:43Z")

</div>

hey @Kankreu ,  
if you use gmsh as a preprocessor, you can also export physical groups directly as node components using the Mesh.SaveGroupsOfNodes option. See also here: [Gmsh 4.12.2](https://gmsh.info/doc/texinfo/gmsh.html#index-Mesh_002eSaveGroupsOfNodes)

---

<div class="post-metadata">

**Author:** ![Kankreu](https://avatars.discourse-cdn.com/v4/letter/k/7ba0ec/32.png) [@Kankreu](https://calculix.discourse.group/u/Kankreu)\
**Post date:** [April 17, 2024, 7:43am UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216/5 "2024-04-17T07:43:52Z")

</div>

Hi,  
thanks for the hint, I have actually done that in the past when I was building directly the model in GMSH.  
…  
//+  
Physical Volume(“tuning\_fork”, 77) = {1};  
//+  
Physical Surface(“clamp”, 78) = {12};  
Mesh.SaveGroupsOfNodes=1;  
Mesh 3;

But I haven’t succeeded (yet) when importing a complex geometry.  
I’m not really skilled with Gmsh.  
Maybe I can do something similar, knowing that I want to work with Surface 9 and 10 of my geometry.  
But the problem is that it currently exports all lines, faces and volume to the input file…While I only need the 2 surfaces and volume.

---

<div class="post-metadata">

**Author:** ![Nobody-86](https://avatars.discourse-cdn.com/v4/letter/n/e495f1/32.png) [@Nobody-86](https://calculix.discourse.group/u/Nobody-86)\
**Post date:** [April 17, 2024, 4:20pm UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216/6 "2024-04-17T16:20:04Z")

</div>

You can simply define the surfaces of interest that you have as a physical group, as you have already done. For complex geometries, you will probably need to look at their numbers beforehand. Then set “Mesh.SaveGroupsOfNodes=-100” to only save nodes that are on surfaces that belong to a physical group. If you also need the nodes on lines, set =-110, or if you only need nodes in the volume and on points =-1001. I think the pattern should be clear.

---

<div class="post-metadata">

**Author:** ![Kankreu](https://avatars.discourse-cdn.com/v4/letter/k/7ba0ec/32.png) [@Kankreu](https://calculix.discourse.group/u/Kankreu)\
**Post date:** [April 18, 2024, 11:19am UTC](https://calculix.discourse.group/t/feature-request-create-nset-from-elset/2216/7 "2024-04-18T11:19:30Z")

</div>

thanks I’ll try that.  
If you are interested, I can share the original geometry and my actual script.

regards,  
Max