Remove Grasshopper Mesh

Hi All,

The plugin of the Finite Element software I use requires a mesh as an input to export/create domains in the FE software. The issue is that I would like to use the FE software’s algorithm to generate the mesh. I use the Mesh Brep component to create the simplest mesh possible from a trimmed surface in Grasshopper, however, this still approximates the surface with triangles and creates unwanted inner faces which will be exported into the FE software as independent domains. Is it possible to create a mesh that consists of one single element following the boundaries of the surface? This single element would need to have an irregular shape with a hole inside. Is this possible at all?

Many thanks,

Meshes are made up of triangle and quads only. These primitive faces can be combined into n-gons but that’s only a visual trick. Or does your FE handle n-gons as single domains?

Hi David,

Not sure but I suppose it does as I cannot see how could it work otherwise. I can give a try anyway to find out. Is there a standard GH component that combines these primitives?

No, n-gons were added to Rhino after grasshopper and there has never been good support for them. You may have to resort to scripting or a plugin.

Hi Mark,

Try this plugin by @Petras_Vestartas


Upload the geometry I will try it in NGon.
Are you exporting then the geometry to other software?


Thanks for this. I will download and give a try.

@Petras_Vestartas, I have simplified the model to keep only one of these surfaces. There is now just one mesh subdivided into 7 triangles.

A picture is also attached which shows how the mesh is imported into the FE software (left-hand side of the picture) and how I would like to import it (right-hand side of the picture). Merging the domains is possible in the software but as many similar domains will be exported, it is time-consuming to do it by hand and it would be good to import them as one single domain.

Please let me know if you have any idea how this could be done.

Thanks a million,


Mesh Ngon.3dm (17.2 KB) Mesh (6.0 KB)

You can convert mesh to ngons like this.
But be aware that ngons is a visualization method and works well for tracking adjacencies.
For structural calculation you would need something else.

I think, if you would just export individual mesh faces to you FE software it will work the same as with simple triangle meshes.

For Abaqus when I was working with engineers we were exporting simple surface in the file format IGS, that worked well. The simple python scripts helped to identify the indexing. So file import export really depends on your workflow.

Yes, you are right, it seems that this method will result in more elements (F=80 instead of 7 previously) so the exported mesh will create even more domains in the other software. I suppose the only solution is if the FE plugin could accept surfaces as inputs rather than meshes.

…the same problem is when you import into 3ds max…