CGNS file with links

ParaView Support
1

I’m trying to import an unstructured CGNS file into ParaView. If I create this file in full the mesh loads in fine and displays some wall distance data attached to the mesh correctly. However, if I create a second file with links to each of the items under Zone in the original mesh file I get the following error:

ERROR: In C:\glr\builds\paraview\paraview-ci\build\superbuild\paraview\src\VTKExtensions\CGNSReader\vtkCGNSReader.cxx, line 1001
vtkCGNSReader (00000292A30283A0): Not enough coordinates in node GridCoordinates


ERROR: In C:\glr\builds\paraview\paraview-ci\build\superbuild\paraview\src\VTKExtensions\CGNSReader\vtkCGNSReader.cxx, line 2828
vtkCGNSReader (00000292A30283A0): Could not allocate memory for connectivity


ERROR: In C:\glr\builds\paraview\paraview-ci\build\superbuild\paraview\src\VTKExtensions\CGNSReader\vtkCGNSReader.cxx, line 4561
vtkCGNSReader (00000292A30283A0): Error Reading file

ERROR: In C:\glr\builds\paraview\paraview-ci\build\superbuild\paraview\src\VTK\Common\ExecutionModel\vtkExecutive.cxx, line 753
vtkPVCompositeDataPipeline (00000292AC5098A0): Algorithm vtkCGNSFileSeriesReader(00000292AC4CA8A0) returned failure for request: vtkInformation (00000292B9BA8580)
  Debug: Off
  Modified Time: 418111
  Reference Count: 1
  Registered Events: (none)
  Request: REQUEST_DATA
  FORWARD_DIRECTION: 0
  ALGORITHM_AFTER_FORWARD: 1
  FROM_OUTPUT_PORT: 0

The idea here is several solution files may be written for a single mesh, so the mesh should be linked in to avoid duplicating very large meshes. CGNS check reports the same results for both files and CGNSView shows the two files are identical when links are followed and when the diff tool is used.

Is it as simple as ParaView does not support links in CGNS files, or is something else going on here? I can provide an input file if it’s the latter. Thanks!

2

The CGNS reader of ParaView is not tested with links. Thus there may be an hidden bug.
It seems you are able to read correctly a mesh without links with paraview. In the case of your other files describing an unsteady flow evolution you can try this:

  • in the first file add mesh with grid coordinates and elements
  • in other files create links for grid coordinates and elements
  • when loading the file series in paraview, toggle the small wheel and activate caching mesh and caching connectivities. It will allow ParaView to only read the mesh coordinates and elements in the first file and just check that links exists without trying to open them in the remaining files.

If you have a small file to reproduce the issue you are welcome to share it.