How to remove details from imported STL file

Hello, 

I have imported a STL file into Salome. I want to clean up the mesh. But nothing happens after I click "Union Faces". What operation shall I do to clean up the mesh? I would like to remesh it using the Netgen mesh in mesh module. Thanks. 

Hi,

you can remesh the stl by using Netgen in the 2D tab in Edit mesh dialog box.

Christophe

Hi  Christophe,

Yes, but the original mesh will still remain there, as someone previoulsy says in the end of this post (https://www.salome-platform.org/forum/forum_11/996229876) . I guess you just let the Netgen mesh superposes the original one, right? 

Hi,

the thread of 2014 talks about importing the stl in GEOM and meshing it.

But if you import the stl in MESH module, right-click Edit mesh, and add NETGEN 2D, you will be able to get coarser or finer elements depending on the parameters you provide.

Christophe

Hi Christophe,

Yes, you're right. I tried again in the mesh module. It can edit the mesh. But I encounter some problems. 

You may look in the following dropbox folder to see my screenshot.

https://www.dropbox.com/sh/rwvotbki5hglo3x/AADVuPTbTNDlhDTbFprVgvcva?dl=0

Problem1: When using different types of mesh types (Quadrilateral, tetrahedral, hexahedral) other than triangular mesh, the meshing progress bar goes back and forth, without end. So I cancel it every time. 

Problem2: If I use triangular, the mesh of the core does not match the shell. 

Problem3: If I use any mesh type, I can not assign NETGEN 3D parameters to change it to be coarse. 

Do you have any clue about this? Or could you please take a look at my STL files? Thank you so much!

Best wishes,

Tryphena

I have one more problem. If I build compound mesh of the two objects, the final mesh will not be consistent....

Hi,

you won't be able to get a mesh of 2 boundary stl shells with Netgen. It can only mesh one closed domain.

Each stl can be remeshed:

- import stl

- edit mesh:

  - 2D: NETGEN

  - Netgen 2D parameters: Max size: 0.1

- Compute

If the mesh is OK for you, edit mesh and add Netgen 3D.

But with this approach, the 2 meshes are non conformal.

It will take much more time to get a conformal mesh.

Hi Christophe,

Thank you for testing out my model. I guess I need to rebuild the model in the geometry by boolean operation. I just have problems with that as well...

Oh, Christophe, how do you cut the mesh as you did in the images you are showing above? Are you saying the mesh is not conformable between the core and shell?  Did you try other cutting planes of different orientations? Thanks. 

Hi,

sorry for the late answer. To get this display, right-click in the view and select Clipping. In the dialog box, press New, Relative and choose a plane.

The two not conformal surfaces are the outer of the core and the inner of the sell. There is no way to tell to remesh these faces with the same triangles.

Maybe you can try to get a better STL without the overalpping faces between the core and the shell (mixed blue-green faces in the screenshot below).

Hi Christophe,

Thank you for getting back to me. Yes, I need a better STL files, or created the cylinders in geometry module. Thanks. 

Previously Christophe Bourcier wrote:

Hi,

sorry for the late answer. To get this display, right-click in the view and select Clipping. In the dialog box, press New, Relative and choose a plane.

The two not conformal surfaces are the outer of the core and the inner of the sell. There is no way to tell to remesh these faces with the same triangles.

Maybe you can try to get a better STL without the overalpping faces between the core and the shell (mixed blue-green faces in the screenshot below).