[MOAB-dev] Quadratic pyramid faces

[Grindeanu, Iulian R.]

 Yes, thank you!
this looks like a bug and you also provided the proper fix

Basically, the arrays for pyramid-face should be corrected in CN::mConnectivityMap[MBPYRAMID]
the up connectivity arrays are fine CN::mUpConnMap[MBPYRAMID]  (about line 428)



Iulian
________________________________________
From: moab-dev-bounces at mcs.anl.gov [moab-dev-bounces at mcs.anl.gov] on behalf of Jacob Hochhalter [Jacob.D.Hochhalter at nasa.gov]
Sent: Monday, November 02, 2015 3:35 PM
To: moab-dev at mcs.anl.gov
Subject: [MOAB-dev] Quadratic pyramid faces

Hello,

I'm working with moab 4.7, compiled during a petsc install, and have
noticed some strange behavior with quadratic pyramids.  I'll do my best
to explain below, without writing too much - let me know if more detail
is needed.

Upon making a set of face entities, consisting of the quadrilateral
faces on a pyramid, moab generates "Tri7" and "Quad7" faces.  The Tri7
faces consist of 3 corner nodes from a triangular face and the 4 midside
nodes from the quadrilateral face.  The Quad7 faces consist of the 4
corner nodes from the quadrilateral face and 3 midisde nodes from a
triangular face.  Note, linear pyramids work fine.  I figured that meant
that there was some inconsistency in the face ordering and midside node
ordering (for quadratic pyramids) and landed in MBCNArrays.hpp, after
snooping around a bit.  There I noticed that the face indexing does not
match the documentation that I have been referring to
(http://homepages.cae.wisc.edu/~tautges/papers/cnmev3.pdf).  Upon making
the change below, and rebuilding, the issue disappeared and moab
generates "Tri6" and "Quad8" faces, as expected.

The following code from lines 89-92:
"
      // pyramid-face
    { 3, 5, {4,3,3,3,3}, {MBQUAD,MBTRI,MBTRI,MBTRI,MBTRI, MBMAXTYPE,
                          MBMAXTYPE, MBMAXTYPE, MBMAXTYPE, MBMAXTYPE,
MBMAXTYPE, MBMAXTYPE},
      {{0,3,2,1}, {0,1,4},  {1,2,4}, {2,3,4}, {3,0,4} } },
"

should be this (the 4th face should be the quadrilateral)
"
      // pyramid-face
    { 3, 5, {3,3,3,3,4}, {MBTRI,MBTRI,MBTRI,MBTRI,MBQUAD, MBMAXTYPE,
                          MBMAXTYPE, MBMAXTYPE, MBMAXTYPE, MBMAXTYPE,
MBMAXTYPE, MBMAXTYPE},
      { {0,1,4},  {1,2,4}, {2,3,4}, {3,0,4}, {0,3,2,1} } },
"

Thanks,
- Jake