# how to get a "thick" poly line from vtkPlaneCutter & vtkPolyData?

**URL:** <https://discourse.vtk.org/t/how-to-get-a-thick-poly-line-from-vtkplanecutter-vtkpolydata/8480>\
**Category:** Development\
**Tags:** python\
**Created:** [May 12, 2022, 5:22am UTC](https://discourse.vtk.org/t/how-to-get-a-thick-poly-line-from-vtkplanecutter-vtkpolydata/8480 "2022-05-12T05:22:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Ingmar](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/i/cc9497/32.png) [@Ingmar](https://discourse.vtk.org/u/Ingmar)\
**Post date:** [May 12, 2022, 5:22am UTC](https://discourse.vtk.org/t/how-to-get-a-thick-poly-line-from-vtkplanecutter-vtkpolydata/8480/1 "2022-05-12T05:22:04Z")

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I am trying to cut a mesh with a plane and render the contour on top of an image (resliced along using the same plane), much like the image below:

![](https://discourse.vtk.org/uploads/default/original/2X/3/3876ac882412c85c83e114de351035c610ff0b6c.png)

The examples at [https://gitlab.kitware.com/vtk/vtk/-/blob/v9.1.0/Filters/Core/Testing/Python/TestPolyDataPlaneCutter.py](https://gitlab.kitware.com/vtk/vtk/-/blob/v9.1.0/Filters/Core/Testing/Python/TestPolyDataPlaneCutter.py) almost do the slicing part that I need  
But when viewing the contour from the direction of the normal the contour / polyline is invisible (see screenshot below left side) as opposed to viewing it from the side (right side of the screenshot below)

So I assume I should try to “dilate” the resulting contour somehow? Any suggestions?

 ![image](https://discourse.vtk.org/uploads/default/original/2X/6/6e66f71cf5ef3559b9e8230d036366b13af8d579.png)

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<div class="post-metadata">

**Author:** ![finetjul](https://discourse.vtk.org/user_avatar/discourse.vtk.org/finetjul/32/154_2.png) [@finetjul](https://discourse.vtk.org/u/finetjul)\
**Post date:** [May 16, 2022, 4:26pm UTC](https://discourse.vtk.org/t/how-to-get-a-thick-poly-line-from-vtkplanecutter-vtkpolydata/8480/2 "2022-05-16T16:26:55Z")

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It seems that you need to turn off shading. You can somehow do so by setting 100% ambient color to your contour actor.

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<div class="post-metadata">

**Author:** ![Ingmar](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/i/cc9497/32.png) [@Ingmar](https://discourse.vtk.org/u/Ingmar)\
**Post date:** [March 19, 2024, 12:47pm UTC](https://discourse.vtk.org/t/how-to-get-a-thick-poly-line-from-vtkplanecutter-vtkpolydata/8480/3 "2024-03-19T12:47:27Z")

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meanwhile I solved it with a vtkTubeFilter