# Getting coordinates of interpolated points in a vtkPolyData instance

**URL:** https://discourse.vtk.org/t/getting-coordinates-of-interpolated-points-in-a-vtkpolydata-instance/641
**Category:** Support
**Created:** [March 29, 2019, 3:00pm UTC](https://discourse.vtk.org/t/getting-coordinates-of-interpolated-points-in-a-vtkpolydata-instance/641 "2019-03-29T15:00:32Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![msmerps](https://discourse.vtk.org/user_avatar/discourse.vtk.org/msmerps/32/1559_2.png) [@msmerps](https://discourse.vtk.org/u/msmerps)
#### Post date: [March 29, 2019, 3:00pm UTC](https://discourse.vtk.org/t/getting-coordinates-of-interpolated-points-in-a-vtkpolydata-instance/641/1 "2019-03-29T15:00:33Z")

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Hi VTK-Experts,  
I’m using vtkParametricSpline to fit a spline to a set of points. I then render the spline via a vtkPolyDataMapper. I would like to access the coordinates of the interpolated points. Can I get that from the vtkPolyDataMapper? If so, how?  
thank you in advance for your help,  
-Merps

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### Author: ![marcomusy](https://discourse.vtk.org/user_avatar/discourse.vtk.org/marcomusy/32/95_2.png) [@marcomusy](https://discourse.vtk.org/u/marcomusy)
#### Post date: [March 29, 2019, 3:27pm UTC](https://discourse.vtk.org/t/getting-coordinates-of-interpolated-points-in-a-vtkpolydata-instance/641/2 "2019-03-29T15:27:46Z")

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try:

```python
mapper.GetInput().GetPoints()
# or as a numpy array:
from vtk.util.numpy_support import vtk_to_numpy 
vtk_to_numpy(mapper.GetInput().GetPoints().GetData())

```

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<div class="post-metadata">

### Author: ![msmerps](https://discourse.vtk.org/user_avatar/discourse.vtk.org/msmerps/32/1559_2.png) [@msmerps](https://discourse.vtk.org/u/msmerps)
#### Post date: [March 30, 2019, 1:37am UTC](https://discourse.vtk.org/t/getting-coordinates-of-interpolated-points-in-a-vtkpolydata-instance/641/3 "2019-03-30T01:37:11Z")

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That did the trick! Thank you Marco. 😄