# How to get polygonal cut surface when I want to use vtkCutter with input of vtkUnstructuredGrid

**URL:** <https://discourse.vtk.org/t/how-to-get-polygonal-cut-surface-when-i-want-to-use-vtkcutter-with-input-of-vtkunstructuredgrid/14965>\
**Category:** Development\
**Created:** [December 5, 2024, 7:23am UTC](https://discourse.vtk.org/t/how-to-get-polygonal-cut-surface-when-i-want-to-use-vtkcutter-with-input-of-vtkunstructuredgrid/14965 "2024-12-05T07:23:45Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![cmodel](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/c/7ab992/32.png) [@cmodel](https://discourse.vtk.org/u/cmodel)\
**Post date:** [December 5, 2024, 7:23am UTC](https://discourse.vtk.org/t/how-to-get-polygonal-cut-surface-when-i-want-to-use-vtkcutter-with-input-of-vtkunstructuredgrid/14965/1 "2024-12-05T07:23:45Z")

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I want to cut a point set (which is unstructured grid) with a plane and want to generate a polygonal cut surface.

But I checked out the doc, warning says polygons can NOT be generated when the input is vtkPolyData/vtkUnstructuredGridBase.

 ![image](https://discourse.vtk.org/uploads/default/original/2X/2/2bb3c7fe6f90695395fa1f5339dcd4a2aac38726.png)

Need I use vtkFlyingEdgesPlaneCutter to get the polygonal cut surface, instead of triangular surface ?