Hi everybody,
A new ParaView python plugin providing a new cell volume computation filter has been published (https://gitlab.kitware.com/paraview/plugins/volumefromcellsfilter).
The Volume From Cells filter can compute cells and total volume of an input vtkUnstructuredGrid, like the actual Cell Size filter, but leads to better results with concave cells.
Indeed, the Cell Size filter relies on a tetrahedralization of the cells before doing computations, resulting to inaccurate results with concave cells (that is an actual limitation of vtkPolyhedron) :
This new method relies on the Green theorem to compute the volume of a cell from its surface, leading to way better results in that case (similar to those we obtain with the same volume composed of tetrahedrons or hexahedrons) :
Many thanks to Eramet Ideas that developed the plugin and supported us to share it publicly.