[MOAB-dev] Puzzled

[Grindeanu, Iulian R.]

yes, the issue is the model.
I had to turn on "Show internal zones" in visit, otherwise I could not see the inverted elements

In this picture, there are the 2 partitions, and some of the hexas have negative orientation, they do not show up with solid color, just as wireframe.

I still can't explain where are the 599 hexas, as I see only 500

the nodes on the interface between partitions are not resolved correctly if the elements are inverted (skinner does not identify them ) 
so 10 nodes are not shared (2x5) and this is why there are 10 more nodes in the "owned" category

(I highlighted 3 of those 10 nodes, A, B, C)

Again, how is this model created?

Thanks,
Iulian
________________________________________
From: moab-dev-bounces at mcs.anl.gov [moab-dev-bounces at mcs.anl.gov] on behalf of Grindeanu, Iulian R. [iulian at mcs.anl.gov]
Sent: Monday, August 11, 2014 6:12 PM
To: Gerd Heber; MOAB dev
Subject: Re: [MOAB-dev] Puzzled

hello,
Yes, it does not add up. Your code seems fine.

 There are other issues I can't explain with this mesh file.
How was this mesh generated?
It seems that elements have a "negative" orientation (negative volume).

moab uses the skinner to identify the boundary, a similar algorithm is used by paraview/visit to show the surface. if some elements are oriented differently, the skinner fails to identify the correct boundary, and it fails later in resolving the shared entities.

I can see only about 5x8x10~400  hexas, total, but mbsize reports 599;

It seems that there are elements filling a cube 10x10x10
about half are hexas, but 5x10x10 is 500, (again, mbsize reports 599)

So is half of the volume filled with prisms, and the other half with hexas?

Iulian
________________________________________
From: moab-dev-bounces at mcs.anl.gov [moab-dev-bounces at mcs.anl.gov] on behalf of Gerd Heber [gheber at hdfgroup.org]
Sent: Monday, August 11, 2014 3:15 PM
To: moab-dev at mcs.anl.gov
Subject: [MOAB-dev] Puzzled

I'm probably doing something stupid, but here it is:

The attached mesh contains 599 hexahedra and 1,140 prisms.
I has 1,408 nodes. It was partitioned into two partitions with mbpart.
When I run the attached program with 'mpirun -np 2 feawdy feawd.h5m' the
output reads:

# hexes :       299     300
# prisms:       570     570
# vertexes:     781     781
# shared:       144     144
# owned:        781     637
# shared/owned: 144     0

The element counts add up nicely, but
I'm confused that the 'owned' counts don't add up to 1408.
What am I missing?

Thanks for your help.
G.
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