Kent Andre wrote: > On ma., 2009-06-22 at 20:57 +0200, Anders Logg wrote: >> On Mon, Jun 22, 2009 at 12:46:09PM -0600, Bartosz Sawicki wrote: >>> Kent Andre wrote: >>>> On ma., 2009-06-22 at 00:40 -0600, Bartosz Sawicki wrote: >>>>> On 22/06/09 12:06 AM, Anders Logg wrote: >>>>>> On Sun, Jun 21, 2009 at 11:36:29PM -0600, Bartosz Sawicki wrote: >>>>>>> On 19/06/09 02:53 PM, kent-...@simula.no wrote: >>>>>>>> When using VMTK the boundary indicators are stored as a set of arrays >>>>>>>> with names >>>>>>>> boundary facet cells, >>>>>>>> boundary facet numbers >>>>>>>> boundary indicators >>>>>>>> The two first arrays are used to find the global facet numbers. >>>>>>>> The function computes a mesh function based on these arrays. >>>>>>>> >>>>>>>> This was what Anders prefered since VMTK does not now anything >>>>>>>> about the global numbering of facets in Dolfin (without linking it into >>>>>>>> Dolfin). >>>>>>>> >>>>>>>> This is not a VMTK specific problem, but I do think VMTK is the only >>>>>>>> mesh-generator >>>>>>>> that let you store boundary indicators at the moment. I guess we >>>>>>>> should add >>>>>>>> this to NetGen as well, both Hans Petter Langtangen and Douglas Arnold >>>>>>>> has >>>>>>>> bugged >>>>>>>> me about this the last few days. >>>>>>> I'm every day user of this functionality. I use Netgen generated >>>>>>> models, >>>>>>> but also other software which add boundary indicators to existing >>>>>>> meshes. Netgen supports boundary indicators quite well, both by geo >>>>>>> files, and by GUI. I don't understand what you want to add? >>>>>> Is it possible to set DOLFIN boundary indicators from Netgen? I didn't >>>>>> know. >>>>> It is definitely possible :) I don't have direct converter from Netgen >>>>> vol to Dolfin xml. Most of my old models were stored in Diffpack grid >>>>> format, so I'm using grid to xml converter. >>>>> Netgen can export to the grid format, so this is not a big issue. >>>> It is not possible to store the boundary indicators in Dolfin format >>>> using Netgen, at the current time. I wrote the Netgen -> dolfin filter >>>> in Netgen so I should know :). >>>> >>>> But it should be possible to include support for that in a similar >>>> fashion as we did in VMTK. >>> You are right that Netgen doesn't support Dolfin XML mesh format. But it >>> doesn't mean that is not possible to use boundary indicators generated >>> by Netgen in Dolfin. Converterting via Diffpack grid file preserves >>> boundaries. >>> >>> The algoritm is simple: >>> 1. Generate mesh using Netgen. >>> 2. Mark boundaries indicators. >>> 3. Export to Diffpack format. >>> 4. Convert Diffpack to XML. >>> 5. Enjoy boundary indicators in Dolfin. >>> >>> cheers, >> Nice, but not optimal. At some point, we need an application that can >> do all of these (and more). There seem to be a couple of different >> options: >> >> 1. Extend Netgen with full support for DOLFIN (and change the toolkit...) >> 2. Extend Gmsh with full support for DOLFIN (and change the toolkit...) >> 3. Extend MeshBuilder to do mesh generation (using for example Netgen) >> 4. ? >> >> Any thoughts on these options? >> >> The problem with (3) is that no one is really developing MeshBuilder, >> except when we pay Kalkulo (http://simula.no/applications/kalkulo/) to >> do it. >> > > It should be fairly easy to include bc indicators in NetGen. I can look > at it, I think I need to update the filter anyway to make sure the mesh > is ordered correctly according to UFC.
Are you going to extend Netgen to enable export into dolfin-xml? You mentioned about some filter, is it somewhere in dolfin repository? I can't find anything. Can upload your code into dolfin-convert utility? > In general it is rather easy to write out the mesh and indicators > compared to actually making it. I bet we can make Gmsh write Dolfin mesh > in just a few hours (but I have not looked at Gmsh). I'm sure that it will be easy. But don't you thing that good converter is more flexible solution? cheers, > The Dolfin XML file format needs to be documented. > > Kent > > _______________________________________________ > DOLFIN-dev mailing list > DOLFIN-dev@fenics.org > http://www.fenics.org/mailman/listinfo/dolfin-dev _______________________________________________ DOLFIN-dev mailing list DOLFIN-dev@fenics.org http://www.fenics.org/mailman/listinfo/dolfin-dev
