Unsymmetric contour rendered by symmetric data

Support
1

Hi,
The problem of “Unsymmetric contour rendered by symmetric data” explained in Paraview support on the following links:
https://discourse.paraview.org/t/unsymmetric-contour-rendered-by-symmetric-data/4118
https://discourse.paraview.org/t/inconsistent-rendering-of-point-data-in-hexahedrall-cells/6536

I have the same problem for representing Displacements and Stresses of FEM analysis which shows asymmetry contour for symmetry structural element that is not acceptable!
I have unstructured quadratic elements and the linear data interpolation shows wrong data in the middle of the cells.
Is there any straightforward solution for this issue?

2

One solution is using "resampletoimagefilter "
https://vtk.org/doc/nightly/html/classvtkResampleToImage.html
vtkPResampleToImage is a filter that resamples the input dataset on a uniform grid. It internally uses vtkProbeFilter to do the probing.

The following code works with VTK > version 7

            vtkGeometryFilter GeometryFilter = vtkGeometryFilter.New();
            GeometryFilter.SetInputData(uGrid);
            GeometryFilter.Update();

            vtkResampleToImage resampletoimagefilter = vtkResampleToImage.New();
            resampletoimagefilter.SetInputConnection(GeometryFilter.GetOutputPort());
            resampletoimagefilter.SetSamplingDimensions(20, 10, 1);
            resampletoimagefilter.UseInputBoundsOn();
            resampletoimagefilter.Update();

            vtkImageDataGeometryFilter imageDataGeometryFilter = vtkImageDataGeometryFilter.New();
            imageDataGeometryFilter.SetInputConnection(resampletoimagefilter.GetOutputPort());
            imageDataGeometryFilter.Update();

            mapper2.SetInputData(imageDataGeometryFilter.GetOutput());
            mapper2.Update();