[GiDlist] Element connectivity problem
Posted: Thu Dec 25, 2003 6:55 pm
Hello, I am trying to prepare a customized connectivity
data in a particular format ("ucd"). The data file
is created correctly following the specified template,
but it is incompatible with the orientations assumed
in the application (using the deal.II FE library).
Is it possible to specify the connectivity ordering in GiD?
For example, GiD has left-handed axes, but deal.II assumes
a right-handed system. Probably if I could work with right-handed
axes in GiD I could solve my problem? What is the recommended
procedure for working with differently ordered systems? I looked
at the "swap" feature and at defining a "local coordinate system"
but could not see how to make these work.
To make clear my problem I list below 2 ucd data files, the first (a) has been
produced by GiD, the second (b) is done by hand. The 2 formats are not
compatible because of the different implied orderings. The GiD file (a)
does not work with my application, whereas (b) is accepted.
Thanks for your help.
Seasons Greetings,
Roger Young.
Industrial Research Ltd.,
Box 31-310 Lower Hutt,
New Zealand.
r.young at irl.cri.nz
Note: the two example files below list the nodal positions
and connectivities of a unit cube. The hex line
gives the connectivity of the element, the quad lines give the
connectivities of the 6 faces. It can be seen that there
is no 1-1 mapping between (a) and (b) which preserves the orientations.
Note the numbering is 0,1,2,.... not 1,2,3....
........................................................................
(a)
8 7 0 0 0
0 0 0 0
1 1 0 0
2 0 1 0
3 0 0 1
4 1 1 0
5 1 0 1
6 0 1 1
7 1 1 1
0 0 hex 7 6 2 4 5 3 0 1
1 0 quad 5 1 0 3
2 1 quad 7 6 2 4
3 2 quad 2 0 1 4
4 3 quad 7 4 1 5
5 4 quad 7 5 3 6
6 5 quad 6 3 0 2
...........................................................................
(b)
8 7 0 0 0
0 0 0 0
1 1 0 0
2 1 0 1
3 0 0 1
4 0 1 0
5 1 1 0
6 1 1 1
7 0 1 1
0 0 hex 0 1 2 3 4 5 6 7
1 0 quad 0 1 2 3
2 1 quad 4 5 6 7
3 2 quad 0 1 5 4
4 3 quad 1 5 6 2
5 4 quad 3 2 6 7
6 5 quad 0 4 7 3
data in a particular format ("ucd"). The data file
is created correctly following the specified template,
but it is incompatible with the orientations assumed
in the application (using the deal.II FE library).
Is it possible to specify the connectivity ordering in GiD?
For example, GiD has left-handed axes, but deal.II assumes
a right-handed system. Probably if I could work with right-handed
axes in GiD I could solve my problem? What is the recommended
procedure for working with differently ordered systems? I looked
at the "swap" feature and at defining a "local coordinate system"
but could not see how to make these work.
To make clear my problem I list below 2 ucd data files, the first (a) has been
produced by GiD, the second (b) is done by hand. The 2 formats are not
compatible because of the different implied orderings. The GiD file (a)
does not work with my application, whereas (b) is accepted.
Thanks for your help.
Seasons Greetings,
Roger Young.
Industrial Research Ltd.,
Box 31-310 Lower Hutt,
New Zealand.
r.young at irl.cri.nz
Note: the two example files below list the nodal positions
and connectivities of a unit cube. The hex line
gives the connectivity of the element, the quad lines give the
connectivities of the 6 faces. It can be seen that there
is no 1-1 mapping between (a) and (b) which preserves the orientations.
Note the numbering is 0,1,2,.... not 1,2,3....
........................................................................
(a)
8 7 0 0 0
0 0 0 0
1 1 0 0
2 0 1 0
3 0 0 1
4 1 1 0
5 1 0 1
6 0 1 1
7 1 1 1
0 0 hex 7 6 2 4 5 3 0 1
1 0 quad 5 1 0 3
2 1 quad 7 6 2 4
3 2 quad 2 0 1 4
4 3 quad 7 4 1 5
5 4 quad 7 5 3 6
6 5 quad 6 3 0 2
...........................................................................
(b)
8 7 0 0 0
0 0 0 0
1 1 0 0
2 1 0 1
3 0 0 1
4 0 1 0
5 1 1 0
6 1 1 1
7 0 1 1
0 0 hex 0 1 2 3 4 5 6 7
1 0 quad 0 1 2 3
2 1 quad 4 5 6 7
3 2 quad 0 1 5 4
4 3 quad 1 5 6 2
5 4 quad 3 2 6 7
6 5 quad 0 4 7 3