[MOAB-dev] ghost exchange with triangles?

[Ryan O'Kuinghttons]

Hi Iulian, cleaning up those few things fixed the issues. I didn't 
realize that I need to exchange only elem related tags on elements, and 
vice versa for nodes. Thanks again!

Ryan

On 11/12/18 22:31, Grindeanu, Iulian R. wrote:
> Hi Ryan,
> Sorry, I missed again your messages
> you are exchanging the tags only on elements (you call  merr = pcomm->exchange_tags(tags, tags, range_ent);), while there are 4 tags active, in the list, globalid, owner, orig_pos and elem coords;
>
> there are some elements for which the tag does not exist (for example edges)
> Also, global id for vertices is not updated, because you exchange tags only on elements; you should exchange on vertices too
>
> something like
> Range verts;
> merr=mb->get_entities_by_dimension(0,0,verts);
>   pcomm->exchange_tags(mbmesh->gid_tag, verts);
>
> what tags are not updated? there are some edges too created automatically by moab (it helps in resolving shared ents and ghosting; on them there is no tag defined, but vtk writer for moab will write default values for them)
>
> also, you are calling resolve shared ents twice (once inside MBMesh_addelements), and once in main program;
>
> Also, you are creating 2 parallel comms ; you need only one
>
> if you resolve inside MBMesh_addelements, you can retrieve that parallel comm with something like
>
>   //! get the indexed pcomm object from the interface
>      static ParallelComm *get_pcomm(Interface *impl, const int index);
> (pass index 0, it will the one created inside MBMesh_addelements)
>
> you can then call ghosting routines
>
> Again, after I run your model, what tags are missing in ghost files?
>
> Iulian
>
>
>
>
> ________________________________________
> From: Ryan O'Kuinghttons <ryan.okuinghttons at noaa.gov>
> Sent: Monday, November 12, 2018 10:45:21 AM
> To: Grindeanu, Iulian R.; moab-dev at mcs.anl.gov
> Subject: Re: ghost exchange with triangles?
>
> Hi Iulian,
>
> After looking into this further I realize that the issue has nothing to
> do with meshes composed of triangles, I do actually get the same issue
> with quadrilaterals (my previous mail said that quads were working). In
> fact, I even see the same issue with the last test case we were
> debugging. The difference between now and then is that the previous test
> case was only calling exchange_tags with the elem_coords tag (as a
> minimal reproducer), which now works in both versions. Now I am seeing
> that every other tag on this test mesh is not being updated by the
> exchange_tags call, even though the debug code says that they are:
>
>     1  ParallelComm(0.04 s) Unpacking tag GLOBAL_ID
>     1  ParallelComm(0.04 s) Unpacking tag orig_pos
>     1  ParallelComm(0.04 s) Unpacking tag owner
>     1  ParallelComm(0.04 s) Done unpacking tags.
>
> The only difference I can see between the elem_coords and the GLOBAL_ID
> or owner tags is that elem_coords is initialized as a double, and the
> others are integers. Is there some reason that a call like the following
> would not work with exchange_tags?
>
> int int_def_val = 0;
>
> merr=moab_mesh->tag_get_handle(GLOBAL_ID_TAG_NAME, 1, MB_TYPE_INTEGER,
> mbmp->gid_tag, MB_TAG_DENSE, &int_def_val);
>
> Ryan
>
> On 11/9/18 10:56, Ryan O'Kuinghttons wrote:
>> Hi Iulian, I ran into an issue with the ghost element exchange this
>> week. I'm using a small test mesh with one quadrilateral, two
>> triangles and two pentagon/hexagons that are broken down into
>> triangles. The ghost exchange seems to work, but the tag exchange does
>> not. I modified the test we were using before, if you want to have a
>> look. When I plot the mesh after the exchange_tags call I see 0s at
>> the the node and element ids locations, which is strange because this
>> works just fine with a mesh of quadrilaterals. The test is on the
>> moab4 branch, at
>> esmf/src/Infrastructure/Mesh/tests/ESMC_MeshMOABGhostUTest. You should
>> call 'make distclean' before rebuilding esmf, then just "make" in test
>> directory and you can run it with:
>>
>> mpirun -np 4 $ESMF_DIR/tests/*/*/ESMC_MeshMOABGhostUTest
>>
>> I am traveling today, and I will be in and out most of the day, but
>> will check email when I can. I have a feeling this is another issue
>> with how we are setting the tags, but hopefully it's a quick fix.
>> Thanks again,
>>