[Gmsh] igs to geo

Christophe Geuzaine cgeuzaine at ulg.ac.be
Mon Jul 21 20:35:46 CEST 2008


Fabian Braennstroem wrote:
> Hi Christophe,
> 
> * On 20 Jul 2008 * Christophe Geuzaine wrote:
> 
>> Fabian Braennstroem wrote:
>>> Hi,
>>>
>>>     I have a small problem, when importing an igs (exported by
>>>             ICEM) geometry. Actually the import works well,
>>>     but as soon as I save it as a geo file, I get a lot more
>>>     points then in the igs file. I attach to snapshots. Do I
>>>     do anything wrong?
>> Not really: the geo export is pretty much there for debugging purposes  
>> only. The reason you get more points is probably that the straight lines  
>> in the iges files are represented e.g. by splines instead of line 
>> segments.
>>
>> Our goal is to mesh iges/step files directly, without converting them  
>> into geo format first...
> 
> Did not know that; sounds nice.
> 
>>>     The view is an extraction of a simple diffuser, which I
>>>     want to mesh with hexa elements.
>>>
>> ...but indeed, for this you would have to convert the iges file into geo  
>> format, since we haven't (yet) interfaced the structured meshing commands 
>> with general CAD files.
> 
> Sounds even better.
> 
>> Why is having more control points a problem?
> 
> It is actually not a problem, but the geo file gets
> completely messy and I am not able to do the definition of
> the mesh by hand!?

to generate hexas with Gmsh you'll currently need to define either 
transfinite volumes (cf. demos/transfinite.geo) or use extrusion (sweeping).



> 
> Thanks!
> Fabian


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