Re: [Gmsh] refine existing mesh

[Christophe Geuzaine]

> On 19 Feb 2018, at 08:38, Johannes Töger  wrote:
> 
> Dear Christophe,
> 
> The new version of your reparametrization algorithm sounds very interesting 
> for our application. Is it possible for you to tell us a bit more about it?

It's a new implementation of the kinds of methods described in the "Cross-patch 
and STL meshing (Compounds)" reference section on gmsh website (see the bottom 
of the page).

> What will it be capable of, and what is the approximate timeline for it?
> 

It will be in Gmsh 4.0 - hopefully within the next couple of months. Gmsh 4.0 
will bring many new features : a stable C++/C/Python API, a new efficient mesh 
file format (MSH4), a  much faster mesh partitioning interface, improved 
OpenCASCADE integration, ...

Christophe

> 
> — 
> Johannes Töger
> 
> Postdoctoral Research Scholar
> National 7T Facility, Lund Biomedical Imaging Center
> Department of Clinical Sciences Lund, Diagnostic Radiology
> Lund University, Sweden
> 
> On Mon, Feb 12, 2018 at 9:41 PM, Christophe Geuzaine  > wrote:
> 
> 
>> On 12 Feb 2018, at 15:42, Juan E. Sanchez > > wrote:
>> 
>> Hello,
>> 
>> Unfortunately, I do not have the geometrical description.  Is there a way to 
>> convert the mesh to a geometrical description?
>> 
> 
> No ; we are working on a new implementation of our “reparametrization” 
> algorithm, which will allow you to do some of this, but it’s not ready yet...
> 
> 
>> Regards,
>> 
>> Juan
>> 
>> On 2/12/18 1:21 AM, Christophe Geuzaine wrote:
 On 10 Feb 2018, at 22:06, Juan E. Sanchez >>>  >> wrote:
 
 Hello,
 
 I have an existing msh file, and a pos file containing a background mesh.  
 Is there a script example showing how to use these files to create a 
 refined mesh using the background field?
 
>>> Start from the geometrical description (not the mesh): this way Gmsh will 
>>> be able to place the new vertices correctly, i.e. on the CAD
>>> gmsh -3 test.geo -bgm test.pos
>>> CG
 Using
 
 gmsh -3 test.msh -bgm test.pos
 
 results in a mesh where there is the same number of nodes and elements, 
 but it appears that the physical entity number is lost:
 
 last element in original file:
 
 36210 4 3 15 15 0 5786 5791 5792 5800
 
 last element in new file:
 
 36210 4 2 0 15 2603 5822 2604 2605
 
 Now all of the mesh elements belong to the same physical entity, 0.
 
 If I perform a "refine by splitting" in the gui, the physical entity 
 information is maintained:
 
 266256 4 2 15 15 42825 10009 41452 9710
 
 The file is a 3d tetrahedral mesh, and it also contains triangular 
 surfaces to impose boundary conditions.
 
 Regards,
 
 Juan
 
 
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 gmsh mailing list
 gmsh@onelab.info  >
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>>> —
>>> Prof. Christophe Geuzaine
>>> University of Liege, Electrical Engineering and Computer Science
>>> http://www.montefiore.ulg.ac.be/~geuzaine 
>>> 
>>> Free software: http://gmsh.info  | http://getdp.info 
>>>  | http://onelab.info 
>> 
>> 
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>> 
> 
> — 
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science 
> http://www.montefiore.ulg.ac.be/~geuzaine 
> 
> 
> Free software: http://gmsh.info  | http://getdp.info 
>  | http://onelab.info 
> 
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> 
> 
> 

— 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine

Free software: http://gmsh.info | http://getdp.info | http://onelab.info

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Re: [Gmsh] refine existing mesh

[Johannes Töger]

Dear Christophe,

The new version of your reparametrization algorithm sounds very interesting
for our application. Is it possible for you to tell us a bit more about it?
What will it be capable of, and what is the approximate timeline for it?


—
Johannes Töger

Postdoctoral Research Scholar
National 7T Facility, Lund Biomedical Imaging Center
Department of Clinical Sciences Lund, Diagnostic Radiology
Lund University, Sweden

On Mon, Feb 12, 2018 at 9:41 PM, Christophe Geuzaine 
wrote:

>
>
> On 12 Feb 2018, at 15:42, Juan E. Sanchez 
> wrote:
>
> Hello,
>
> Unfortunately, I do not have the geometrical description.  Is there a way
> to convert the mesh to a geometrical description?
>
>
> No ; we are working on a new implementation of our “reparametrization”
> algorithm, which will allow you to do some of this, but it’s not ready
> yet...
>
>
> Regards,
>
> Juan
>
> On 2/12/18 1:21 AM, Christophe Geuzaine wrote:
>
> On 10 Feb 2018, at 22:06, Juan E. Sanchez  mailto:juan.e.sanc...@gmail.com >> wrote:
>
> Hello,
>
> I have an existing msh file, and a pos file containing a background mesh.
> Is there a script example showing how to use these files to create a
> refined mesh using the background field?
>
> Start from the geometrical description (not the mesh): this way Gmsh will
> be able to place the new vertices correctly, i.e. on the CAD
> gmsh -3 test.geo -bgm test.pos
> CG
>
> Using
>
> gmsh -3 test.msh -bgm test.pos
>
> results in a mesh where there is the same number of nodes and elements,
> but it appears that the physical entity number is lost:
>
> last element in original file:
>
> 36210 4 3 15 15 0 5786 5791 5792 5800
>
> last element in new file:
>
> 36210 4 2 0 15 2603 5822 2604 2605
>
> Now all of the mesh elements belong to the same physical entity, 0.
>
> If I perform a "refine by splitting" in the gui, the physical entity
> information is maintained:
>
> 266256 4 2 15 15 42825 10009 41452 9710
>
> The file is a 3d tetrahedral mesh, and it also contains triangular
> surfaces to impose boundary conditions.
>
> Regards,
>
> Juan
>
>
> ___
> gmsh mailing list
> gmsh@onelab.info 
> http://onelab.info/mailman/listinfo/gmsh
>
> —
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
>
>
>
> ___
> gmsh mailing list
> gmsh@onelab.info
> http://onelab.info/mailman/listinfo/gmsh
>
>
> —
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
>
> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
>
>
> ___
> gmsh mailing list
> gmsh@onelab.info
> http://onelab.info/mailman/listinfo/gmsh
>
>
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Re: [Gmsh] refine existing mesh

[Christophe Geuzaine]

> On 12 Feb 2018, at 15:42, Juan E. Sanchez  wrote:
> 
> Hello,
> 
> Unfortunately, I do not have the geometrical description.  Is there a way to 
> convert the mesh to a geometrical description?
> 

No ; we are working on a new implementation of our “reparametrization” 
algorithm, which will allow you to do some of this, but it’s not ready yet...


> Regards,
> 
> Juan
> 
> On 2/12/18 1:21 AM, Christophe Geuzaine wrote:
>>> On 10 Feb 2018, at 22:06, Juan E. Sanchez >> > wrote:
>>> 
>>> Hello,
>>> 
>>> I have an existing msh file, and a pos file containing a background mesh.  
>>> Is there a script example showing how to use these files to create a 
>>> refined mesh using the background field?
>>> 
>> Start from the geometrical description (not the mesh): this way Gmsh will be 
>> able to place the new vertices correctly, i.e. on the CAD
>> gmsh -3 test.geo -bgm test.pos
>> CG
>>> Using
>>> 
>>> gmsh -3 test.msh -bgm test.pos
>>> 
>>> results in a mesh where there is the same number of nodes and elements, but 
>>> it appears that the physical entity number is lost:
>>> 
>>> last element in original file:
>>> 
>>> 36210 4 3 15 15 0 5786 5791 5792 5800
>>> 
>>> last element in new file:
>>> 
>>> 36210 4 2 0 15 2603 5822 2604 2605
>>> 
>>> Now all of the mesh elements belong to the same physical entity, 0.
>>> 
>>> If I perform a "refine by splitting" in the gui, the physical entity 
>>> information is maintained:
>>> 
>>> 266256 4 2 15 15 42825 10009 41452 9710
>>> 
>>> The file is a 3d tetrahedral mesh, and it also contains triangular surfaces 
>>> to impose boundary conditions.
>>> 
>>> Regards,
>>> 
>>> Juan
>>> 
>>> 
>>> ___
>>> gmsh mailing list
>>> gmsh@onelab.info 
>>> http://onelab.info/mailman/listinfo/gmsh
>> —
>> Prof. Christophe Geuzaine
>> University of Liege, Electrical Engineering and Computer Science
>> http://www.montefiore.ulg.ac.be/~geuzaine
>> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
> 
> 
> ___
> gmsh mailing list
> gmsh@onelab.info
> http://onelab.info/mailman/listinfo/gmsh

— 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine

Free software: http://gmsh.info | http://getdp.info | http://onelab.info

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Re: [Gmsh] refine existing mesh

[Juan E. Sanchez]

Hello,

Unfortunately, I do not have the geometrical description.  Is there a 
way to convert the mesh to a geometrical description?


Regards,

Juan

On 2/12/18 1:21 AM, Christophe Geuzaine wrote:



On 10 Feb 2018, at 22:06, Juan E. Sanchez > wrote:


Hello,

I have an existing msh file, and a pos file containing a background 
mesh.  Is there a script example showing how to use these files to 
create a refined mesh using the background field?




Start from the geometrical description (not the mesh): this way Gmsh 
will be able to place the new vertices correctly, i.e. on the CAD


gmsh -3 test.geo -bgm test.pos

CG


Using

gmsh -3 test.msh -bgm test.pos

results in a mesh where there is the same number of nodes and 
elements, but it appears that the physical entity number is lost:


last element in original file:

36210 4 3 15 15 0 5786 5791 5792 5800

last element in new file:

36210 4 2 0 15 2603 5822 2604 2605

Now all of the mesh elements belong to the same physical entity, 0.

If I perform a "refine by splitting" in the gui, the physical entity 
information is maintained:


266256 4 2 15 15 42825 10009 41452 9710

The file is a 3d tetrahedral mesh, and it also contains triangular 
surfaces to impose boundary conditions.


Regards,

Juan


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—
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine

Free software: http://gmsh.info | http://getdp.info | http://onelab.info




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Re: [Gmsh] refine existing mesh

[Christophe Geuzaine]

> On 10 Feb 2018, at 22:06, Juan E. Sanchez  wrote:
> 
> Hello,
> 
> I have an existing msh file, and a pos file containing a background mesh.  Is 
> there a script example showing how to use these files to create a refined 
> mesh using the background field?
> 

Start from the geometrical description (not the mesh): this way Gmsh will be 
able to place the new vertices correctly, i.e. on the CAD

gmsh -3 test.geo -bgm test.pos

CG

> Using
> 
> gmsh -3 test.msh -bgm test.pos
> 
> results in a mesh where there is the same number of nodes and elements, but 
> it appears that the physical entity number is lost:
> 
> last element in original file:
> 
> 36210 4 3 15 15 0 5786 5791 5792 5800
> 
> last element in new file:
> 
> 36210 4 2 0 15 2603 5822 2604 2605
> 
> Now all of the mesh elements belong to the same physical entity, 0.
> 
> If I perform a "refine by splitting" in the gui, the physical entity 
> information is maintained:
> 
> 266256 4 2 15 15 42825 10009 41452 9710
> 
> The file is a 3d tetrahedral mesh, and it also contains triangular surfaces 
> to impose boundary conditions.
> 
> Regards,
> 
> Juan
> 
> 
> ___
> gmsh mailing list
> gmsh@onelab.info
> http://onelab.info/mailman/listinfo/gmsh

— 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine

Free software: http://gmsh.info | http://getdp.info | http://onelab.info

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