# vtkClipPolyData and vtkXMLUnstructuredGridReader

**URL:** https://discourse.vtk.org/t/vtkclippolydata-and-vtkxmlunstructuredgridreader/1779
**Category:** Support
**Created:** [September 18, 2019, 8:14am UTC](https://discourse.vtk.org/t/vtkclippolydata-and-vtkxmlunstructuredgridreader/1779 "2019-09-18T08:14:38Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![hamid\_badi](https://discourse.vtk.org/user_avatar/discourse.vtk.org/hamid_badi/32/895_2.png) [@hamid\_badi](https://discourse.vtk.org/u/hamid_badi)
#### Post date: [September 18, 2019, 8:14am UTC](https://discourse.vtk.org/t/vtkclippolydata-and-vtkxmlunstructuredgridreader/1779/1 "2019-09-18T08:14:38Z")

</div>

Hello,  
I try to display some filled isolines from a vtu file containing a 2d mesh and a scalar node field. Based on this [example](https://vtk.org/Wiki/VTK/Examples/Cxx/VisualizationAlgorithms/FilledContours), it seems that vtkClipPolyData is not compatible with vtkXMLUnstructuredGridReader.  
Moreover i can see what is the best way to display isolines, either vtkContour, vtkClip, vtkMarchingSquares…  
Best regards.