[Paraview] Combination of polygonal-data and unstructured grid?

[Armin Wehrfritz]

Hi Stefan,

If I understand your problem correctly, then you are looking for
polyhedral cells (i.e. N face cells, where each face is a M edge
polygon). Polyhedral cells are commonly used in Computational Fluid
Dynamics codes, as e.g. OpenFOAM, and VTK/ParaView support them already
for quite some time (i.e. since around 2010), see [1] for more details.

> My problem is now i have a set of complex shaped volumes (dual-grid
> data) which cannot be found in the list of cell types for
> unstructured grid data. Therefore i use the polygonal data and color
> each cell with one color. Of course for further analysis (e.g.
> integration of the cell volumes, volume gradient and so on) i need a
> way to give a set of (closed surface) poly-data elements a kind
> connection to form a volume to handle them together.
In which file format do you store your data?

For example, the unstructured VTK XML format [2] has support for
polyhedral cells. An alternative would be the XDMF file format [3] to
which I recently added polyhedral cell support [4,5]. Please note that
the latest release versions of VTK (7.0) or ParaView (5.1) don't support
the polyhedral cells in XDMF yet, but the nightly builds and the
upcoming releases (i.e. VTK 7.1 and ParaView 5.2) will have this feature.

Cheers,
Armin


[1] http://www.vtk.org/Wiki/VTK/Polyhedron_Support
[2] http://www.vtk.org/Wiki/VTK_XML_Formats
[3] http://www.xdmf.org
[4] 
https://gitlab.kitware.com/xdmf/xdmf/commit/0a9fbd0590dff8a677c86754169cd2ccd72fe4b1
[5] 
https://gitlab.kitware.com/vtk/vtk/commit/802c9b61de28e560c2659d2af76660bbb49c68be


-- 
Armin Wehrfritz, Dipl.-Ing. (M.Sc.)
Aalto University, School of Engineering
Department of Mechanical Engineering
PO Box 14300
FI-00076 Aalto, Finland
+358 50 4340607
armin.wehrfritz at aalto.fi
https://people.aalto.fi/armin_wehrfritz