# Mysterious points found when clipping a Delaunay filtered model

**URL:** https://discourse.vtk.org/t/mysterious-points-found-when-clipping-a-delaunay-filtered-model/7805
**Category:** Support
**Created:** [February 10, 2022, 6:33am UTC](https://discourse.vtk.org/t/mysterious-points-found-when-clipping-a-delaunay-filtered-model/7805 "2022-02-10T06:33:51Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![dwventer](https://discourse.vtk.org/user_avatar/discourse.vtk.org/dwventer/32/1579_2.png) [@dwventer](https://discourse.vtk.org/u/dwventer)
#### Post date: [February 10, 2022, 6:33am UTC](https://discourse.vtk.org/t/mysterious-points-found-when-clipping-a-delaunay-filtered-model/7805/1 "2022-02-10T06:33:51Z")

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Hi, I have a strange problem that I do not understand why it is happening.

I have a ply file model that I crop to a small section using vtkClipPolyData and vtkPlanes. This is the resulting clipped image:  
 ![image](https://discourse.vtk.org/uploads/default/original/2X/9/96adf69dbe66fdb303d6abb1b00c34e7a5aeaafc.png)

I then run a vtkDelaunay3D filter on the model to get the following:  
 ![image](https://discourse.vtk.org/uploads/default/original/2X/a/aa8e43310f5b5dc13ce4218d3e158549f66a425b.png)

Now when I try to cut the model with vtkCutter using vtkPlane as the cut function I get the following cut (coloured in blue):

![image](https://discourse.vtk.org/uploads/default/original/2X/0/01354e764f0290326f4e4ac6c49dd6f39d0629cb.png)

Notice the mysterious points in the middle area that is not supposed to be there. What is causing this? Thanks

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### Author: ![dwventer](https://discourse.vtk.org/user_avatar/discourse.vtk.org/dwventer/32/1579_2.png) [@dwventer](https://discourse.vtk.org/u/dwventer)
#### Post date: [February 11, 2022, 4:22am UTC](https://discourse.vtk.org/t/mysterious-points-found-when-clipping-a-delaunay-filtered-model/7805/2 "2022-02-11T04:22:21Z")

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Hi,

I don’t know if this is the correct solution but I have passed the output of the Delaunay filter to a Geometry filter (vtkGeometryFilter).This seemed to have removed the mysterious points.

My reasoning was that the output of the Delaunay filter gave me unstructured grid data that I think was causing the problems. The vtkGeometryFilter then converted the unstructured data to polygonal type.

Regards,  
Daniel