# 3D rendering for polydata points

**URL:** https://discourse.vtk.org/t/3d-rendering-for-polydata-points/1365
**Category:** Support
**Created:** [July 17, 2019, 11:22am UTC](https://discourse.vtk.org/t/3d-rendering-for-polydata-points/1365 "2019-07-17T11:22:44Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![vasya\_slot](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/v/a3d4f5/32.png) [@vasya\_slot](https://discourse.vtk.org/u/vasya_slot)
#### Post date: [July 17, 2019, 11:22am UTC](https://discourse.vtk.org/t/3d-rendering-for-polydata-points/1365/1 "2019-07-17T11:22:44Z")

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I am a VTK beginner.  
I have a large number of points with some attribute value for each point. I want to build a 3D volume in VTK / Paraview with the ability to apply various filters. I tried to use Delaunau3D in Paraview, but this filter does not correctly display hollow objects, such as a thick-walled tube. How can I do it?

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### Author: ![Paulo\_Carvalho](https://discourse.vtk.org/user_avatar/discourse.vtk.org/paulo_carvalho/32/370_2.png) [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [July 21, 2019, 9:35pm UTC](https://discourse.vtk.org/t/3d-rendering-for-polydata-points/1365/2 "2019-07-21T21:35:33Z")

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Hello, Vasy,

From your question I understand that you have a point cloud, then use Delaunay3D filter to build a mesh from it. But the result of the filter being rendered a thin wireframe and you want to display the edges as tubes, right?  
If I understood correctly, then you need the vtkTubeFilter to convert the wireframe into a tubular truss:

```
(...) //previous VTK pipeline calls

// build a tube around the polygonal line
vtkSmartPointer<vtkTubeFilter> tubeFilter =
          vtkSmartPointer<vtkTubeFilter>::New();
tubeFilter->SetInputConnection( <output from vtkDelaunay3D goes here> );
tubeFilter->SetRadius(10); //default is .5
tubeFilter->SetNumberOfSides(50);
tubeFilter->Update();

(...) // the rest of the VTK pipeline calls

```

I hope this helps.