# Extract Points from vtkParametricSpline
**URL:** https://discourse.vtk.org/t/extract-points-from-vtkparametricspline/5715
**Category:** Support
**Created:** [May 6, 2021, 11:30am UTC](https://discourse.vtk.org/t/extract-points-from-vtkparametricspline/5715 "2021-05-06T11:30:40Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@jamesnoel](https://discourse.vtk.org/u/jamesnoel)
#### Post date: [May 6, 2021, 11:30am UTC](https://discourse.vtk.org/t/extract-points-from-vtkparametricspline/5715/1 "2021-05-06T11:30:40Z")
Dear All,
Does anyone know how I can extract all points calculated in the vtkParametric spline? I only seem to be able to return the control points I inserted as input.
Greatly appreciate any help.
Best Regards,
James
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### Author:  [@will.schroeder](https://discourse.vtk.org/u/will.schroeder)
#### Post date: [May 6, 2021, 2:48pm UTC](https://discourse.vtk.org/t/extract-points-from-vtkparametricspline/5715/2 "2021-05-06T14:48:51Z")
Why wouldn’t you just create a small loop to evaluate the parametric coordinate u from [0,1] ? Using void Evaluate(double u[3], double Pt[3], double Du[9]) override;
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### Author:  [@jamesnoel](https://discourse.vtk.org/u/jamesnoel)
#### Post date: [May 13, 2021, 8:56am UTC](https://discourse.vtk.org/t/extract-points-from-vtkparametricspline/5715/3 "2021-05-13T08:56:58Z")
Thanks! It worked well
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### Author:  [@will.schroeder](https://discourse.vtk.org/u/will.schroeder)
#### Post date: [May 13, 2021, 10:10am UTC](https://discourse.vtk.org/t/extract-points-from-vtkparametricspline/5715/4 "2021-05-13T10:10:20Z")
Great. I wondered if the splines should have a GetLength() method so that it’s easier to figure out what u-spacing to use… I might add that at some point in the future. It’s tricky though because obviously uniform u spacing does not translate into regular world point spacing.