Finite Element : using triangular mesh vertices instead of hexahedric

[pasquet]

Hello !

How are you ?
I am an old (heavy ?) Rhino user and currently generating a collection of 3d-scanned objects.

— Is it possible to use a finite element method with meshes made from triangular vertices instead of hexahedric ?

Thank you !

O.

[fredvoisin]

Hi Oliv,

if it can help, Gmesh (linux) can do triangular vertices meshes which may be used for finite element methods.

All the best.
Fred

[pasquet]

Hey Fred !!

Thank you for your answer !!
I am exporting triangular vertices meshes from Rhino as STL files.
I then convert them into MESH format using Gmsh (super: http://gmsh.info).
Finally I want to import them into Modalys. But I could only import hexahedric meshes using the command:
(setq coco (make-mesh 'read-from-file “mesh_from_gmsh.mesh”))

PS: .MESH files can also be .MODAL ones.

[pasquet]

@pasquet

meshes made from triangular vertices instead of hexahedric

If I read the Modalys documentation more carefully (Finite Elements.pdf)… It is specified that it only deals with hexahedric meshes.

[louis.goldford]

Hello to all — Was there any resolution here?

I’m also attempting to use Gmsh for mesh creation / conversion. I’m unable to convert triangles to hexahedra in Gmsh, though. If anybody has a suggestion, please let me know.

Many thanks! —
Louis

[pasquet]

You can here find some info that may be useful for you:

How to read 3D mesh files in Modalys for Max

Hello ! Sorry for my late answer !! — You can indeed quadrangulate some meshes using… “quadrangulate” in Grasshopper for instance. This does not always work well though. Rhino 7 now allows the creation of quad meshes from surfaces, solids, meshes, or SubDs (!!) and works better for complex forms. — After Baking with Grasshopper, I personally export that Rhino mesh as a STL file and convert into a .mesh (INRIA mEdit file) file using the lovely Gmsh (https://gmsh.info). — However, thes…

[piechaud]

Hi everyone,

Sorry to catch this that late!
1- Quads should work as well as hexahedra 2- Triangles will be best avoided!

Could anyone provide with a questionable .mesh file generated by gmsh? I recently came across a similar problem due to some dialectal idiosyncrasy (worked around in Modalys 3.6 beta ).

Also you should know that 3.6 beta now imports .obj although this is not quite documented…

Thanks, that would help a lot!
Robert

[pasquet]

素晴らしい！

[fredfradet]

Hello, I had a successful result with MeshLab : tri to quad by smart triangle pairing

I’m using Fusion 360 —> creating a mesh, exporting to OBJ —> then converting via MeshLab

[antonioflorenca]

Hi,

A great and solid (and free) alternative is Instant Meshes: igl | Interactive Geometry Lab | ETH Zurich | Instant Field-Aligned Meshes

All the best,
António

[pasquet]

Dear Antonio,

Yes it is !
Late thanks !

O.