Anders Logg wrote: > On Tue, Jun 23, 2009 at 09:25:19AM +0200, 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. >> >> 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). >> >> The Dolfin XML file format needs to be documented. >> > > Yes, and there's some ongoing work on creating schemas and validating > against these schemas when parsing (Relax-NG using libxml2). > > Ilmar has been working on it but I don't know the current > status. Ilmar? Ola? > > The functions for validating the schemas are in place, the use the function validate in NewXMLFile.cpp.
The schema file is available on the fenics server as pub/misc/dolfin.rng now, and is used in the validate function. We might want to add a release number to this file, e.g. dolfin-0.9.2.rng, as the schema might change as new mesh types are added. ilmar > ------------------------------------------------------------------------ > > _______________________________________________ > 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
