# Export linear extrusion as .ply file
**URL:** https://discourse.vtk.org/t/export-linear-extrusion-as-ply-file/2092
**Category:** Support
**Created:** [November 13, 2019, 2:50pm UTC](https://discourse.vtk.org/t/export-linear-extrusion-as-ply-file/2092 "2019-11-13T14:50:54Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Mskovmand](https://discourse.vtk.org/u/Mskovmand)
#### Post date: [November 13, 2019, 2:50pm UTC](https://discourse.vtk.org/t/export-linear-extrusion-as-ply-file/2092/1 "2019-11-13T14:50:54Z")
Hello,
I’ve had great luck exporting colored glyphs as .ply files for use in other software.
Now I’m trying to export some “cylinders” which are created using a linear extrusion, more specifically, like this:
```
disk = vtk.vtkDiskSource()
disk.SetCircumferentialResolution(128)
disk.SetRadialResolution(1)
disk.SetOuterRadius(2)
disk.SetInnerRadius(1)
pipe = vtk.vtkLinearExtrusionFilter()
pipe.SetInputConnection(disk.GetOutputPort())
pipe.SetExtrusionTypeToNormalExtrusion()
pipe.SetVector(0, 0, 1)
pipe.SetScaleFactor(5)
pipe.Update()
```
However, doing this, and writing it to a .ply file
```
writer = vtk.vtkPLYWriter()
writer.SetFileName('pipe.ply')
writer.SetInputConnection(pipe.GetOutputPort())
writer.Write()
```
only leaves me with 2 disks, one upper and one lower, and not the “pipe” that I’m seeing if I add this to a render window.
I tried the same thing, using a cylinder instead of my extruded disk, and here I had success.
Does anyone know what I am missing?
---
### Author:  [@Mskovmand](https://discourse.vtk.org/u/Mskovmand)
#### Post date: [November 13, 2019, 3:04pm UTC](https://discourse.vtk.org/t/export-linear-extrusion-as-ply-file/2092/2 "2019-11-13T15:04:40Z")
I’m clearly an idiot here, delete if you want.
The answer:
Add a triangle filter.
```
fil = vtk.vtkTriangleFilter()
fil.SetInputConnection(pipe.GetOutputPort())
```
and use this in the writer and it works fine.