# vtkTubeFilter with rounded corners
**URL:** https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924
**Category:** Support
**Created:** [July 11, 2023, 6:18am UTC](https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924 "2023-07-11T06:18:02Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@liuzhongshu](https://discourse.vtk.org/u/liuzhongshu)
#### Post date: [July 11, 2023, 6:18am UTC](https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924/1 "2023-07-11T06:18:02Z")
Currently, I have a tube with vtkTubeFilter that has a 90 degree angle at the ends of the tube. Can I change the end with a rounded corner.
In other words, I’d like to change the endpoint of the tube from ‘]’ to ‘)’
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### Author:  [@Stephen\_Aylward](https://discourse.vtk.org/u/Stephen_Aylward)
#### Post date: [July 11, 2023, 1:48pm UTC](https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924/2 "2023-07-11T13:48:34Z")
Hi,
I do not believe that it is possible to do that via the vtkTubeFilter, but I have approximated this in the past by also rendering a sphere at the coordinates of the end points of the tube.
Hope that works for you as well.
Stephen
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### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [July 11, 2023, 10:23pm UTC](https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924/3 "2023-07-11T22:23:14Z")
Hello,
I believe you’re better off if you round the corners of the input polyline (see [graphics - How to "soften" the edges of a polyline? - Stack Overflow](https://stackoverflow.com/questions/10162864/how-to-soften-the-edges-of-a-polyline)) before processing it with the tube filter. This way you’ll likely get tubes with round elbows. Here ([https://public.kitware.com/pipermail/vtkusers/2014-May/083921.html](https://public.kitware.com/pipermail/vtkusers/2014-May/083921.html)) you can find an algorithm in Python to produce rounded corners given an input 3D path/polyline.
Alternativelly, you can use the following pipeline: edges → implicit modeler → distance field → compute isosurface (e.g. for 1") → a smooth tube around the edges with 1" radius. Here’s a Python code illustrating that:
```python
def polylineToTube(edges, radius, resolution=10, sampling=400):
modeller = vtk.vtkImplicitModeller()
modeller.SetSampleDimensions(sampling, sampling, sampling)
modeller.SetInputData(edges)
contours = vtk.vtkContourFilter()
contours.SetInputConnection(modeller.GetOutputPort())
contours.SetValue(0, radius) # generate iso-surface at radius
contours.Update()
return contours
```
source: [https://discourse.vtk.org/t/how-to-show-a-polyline-with-arbitrary-width-and-nice-joins-between-the-nodes](https://discourse.vtk.org/t/how-to-show-a-polyline-with-arbitrary-width-and-nice-joins-between-the-nodes)
I hope this helps,
PC
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### Author:  [@liuzhongshu](https://discourse.vtk.org/u/liuzhongshu)
#### Post date: [August 16, 2023, 5:31am UTC](https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924/4 "2023-08-16T05:31:05Z")
Thanks @Stephen_Aylward@Paulo_Carvalho
I just want a round corner at the end of the tube, I tried add a sphere at the end, but the effect didn’t satisfy me, because my tube is translucent, maybe hemisphere would be better, but I don’t know how to add a hemisphere.
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### Author:  [@Stephen\_Aylward](https://discourse.vtk.org/u/Stephen_Aylward)
#### Post date: [August 16, 2023, 3:27pm UTC](https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924/5 "2023-08-16T15:27:38Z")
Perhaps another option is to specify the final tube endpoints to have decreasing radii so as to approximate a rounded end cap?
Otherwise, it might be a good option to add to the TubeFilter directly, rather than trying to piece together different actors. We’d welcome that contribution to VTK!
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### Author:  [@liuzhongshu](https://discourse.vtk.org/u/liuzhongshu)
#### Post date: [August 17, 2023, 5:14am UTC](https://discourse.vtk.org/t/vtktubefilter-with-rounded-corners/11924/6 "2023-08-17T05:14:58Z")
Good idea, I tried it and it works. Thanks.