[vtkusers] ExodusII problem or bug?? Please help

[David Thompson]

Hi Davood,

The ExodusII reader was created before VTK had Soeren Gebbert's 9-node  
quadratic elements, so the 8-node quad was used as an approximation.  
It appears that vtkExodusIIReaderPrivate::DetermineVtkCellType needs  
to be changed to use the bi-quadratic quad, but there may be more  
depending on the order nodes are specified in by Exodus vs. VTK (see  
vtkExodusIIReader::GetCacheOrRead around line 2225 for what's done  
with hexahedra).

If someone wants to create a patch, I'll be happy to review it in  
Gerrit.

	David

On May 12, 2011, at 9:17 , Davood Ansari wrote:

> Hi all
>
> I am having some trouble with reading ExodusII files generated from  
> Cubit 12.
> The elements are supposed to be (and based from what I see in  
> the .exo file are)
> biqudratic quads that have 9 points. When I read the file using  
> vtkExodusIIReader,
> however, I get quadratic quads with 8 sampling points.
>
> Any idea what is going one?
>
> Attached is the header for my .exo mesh file, as you see  
> num_nod_per_el1 = 9 ; but I still get 8 point quadratic quad in VTK??
>
>
> netcdf sphere {
> dimensions:
>     len_string = 33 ;
>     len_line = 81 ;
>     four = 4 ;
>     time_step = UNLIMITED ; // (0 currently)
>     num_dim = 3 ;
>     num_nodes = 386 ;
>     num_elem = 96 ;
>     num_el_blk = 1 ;
>     num_qa_rec = 1 ;
>     num_el_in_blk1 = 96 ;
>     num_nod_per_el1 = 9 ;
> variables:
>     double time_whole(time_step) ;
>     char qa_records(num_qa_rec, four, len_string) ;
>     char coor_names(num_dim, len_string) ;
>     char eb_names(num_el_blk, len_string) ;
>     int elem_map(num_elem) ;
>     int eb_status(num_el_blk) ;
>     int eb_prop1(num_el_blk) ;
>         eb_prop1:name = "ID" ;
>     int connect1(num_el_in_blk1, num_nod_per_el1) ;
>         connect1:elem_type = "QUAD9" ;
>     double coord(num_dim, num_nodes) ;
>
> // global attributes:
>         :api_version = 4.57f ;
>         :version = 4.57f ;
>         :floating_point_word_size = 8 ;
>         :file_size = 0 ;
>         :title = "cubit(/home/dansari/Desktop/sphere/sphere.exo):  
> 03/22/2011: 19:24:22" ;
>
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
>
> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers