# vtkProbe not passing scalar values?
**URL:** https://discourse.vtk.org/t/vtkprobe-not-passing-scalar-values/13272
**Category:** Support
**Created:** [February 6, 2024, 4:59pm UTC](https://discourse.vtk.org/t/vtkprobe-not-passing-scalar-values/13272 "2024-02-06T16:59:49Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@rexthor](https://discourse.vtk.org/u/rexthor)
#### Post date: [February 6, 2024, 4:59pm UTC](https://discourse.vtk.org/t/vtkprobe-not-passing-scalar-values/13272/1 "2024-02-06T16:59:49Z")
I have a vtkXMLPolyData file that stores point data (temperature, etc.), I wanted to probe it with vtkProbeFilter. The resulting file (`out.vtp`) has all of the point data array names, but the ranges of the values in those arrays is all [0, 0]? I have also verified that the data (which sort of looks like a cone) has a tip at the origin, and does pass through the radius 1 area with nodes having nonzero temperature.
```python
import sys, vtk
def project_onto_sphere(pd):
s = vtk.vtkSphereSource()
s.SetThetaResolution(60)
s.SetPhiResolution(30)
s.SetRadius(1)
pf = vtk.vtkProbeFilter()
pf.SetInputConnection(s.GetOutputPort())
pf.SetSourceData(pd)
pf.Update()
return pf.GetOutput()
if __name__ == " __main__":
r = vtk.vtkXMLPolyDataReader()
r.SetFileName(sys.argv[1])
r.Update()
b = project_onto_sphere(r.GetOutput())
w = vtk.vtkXMLPolyDataWriter()
w.SetFileName("out.vtp")
w.SetInputData(b)
w.Write()
```
---
### Author:  [@rexthor](https://discourse.vtk.org/u/rexthor)
#### Post date: [February 6, 2024, 7:04pm UTC](https://discourse.vtk.org/t/vtkprobe-not-passing-scalar-values/13272/2 "2024-02-06T19:04:54Z")
I tried to increase the node density, that didn’t seem to work either:
```python
def project_onto_sphere(pd):
s = vtk.vtkSphereSource()
s.SetThetaResolution(60)
s.SetPhiResolution(30)
s.SetRadius(1)
tf = vtk.vtkTriangleFilter()
tf.SetInputData(pd)
lf = vtk.vtkLoopSubdivisionFilter()
lf.SetInputConnection(tf.GetOutputPort())
lf.SetNumberOfSubdivisions(3)
lf.Update()
pf = vtk.vtkProbeFilter()
pf.SetInputConnection(s.GetOutputPort())
pf.SetSourceConnection(lf.GetOutputPort())
pf.Update()
return pf.GetOutput()
```
---
### Author:  [@rexthor](https://discourse.vtk.org/u/rexthor)
#### Post date: [February 6, 2024, 8:50pm UTC](https://discourse.vtk.org/t/vtkprobe-not-passing-scalar-values/13272/3 "2024-02-06T20:50:44Z")
Based on [this post](https://discourse.paraview.org/t/how-to-transfer-scalar-data-from-mesh-a-to-mesh-b/2100/2), I tried vtkResampleWithDataset … also only produced zero scalar values. I also gather [from here](https://discourse.paraview.org/t/resample-with-dataset-on-thin-surfaces/4759) that using vtkResampleWithDataset using the scalars from _a surface_ is probably not going to work.
I was able to get output somewhat similar to what I was expecting by using `vtkPointInterpolator` … but I still don’t understand why `vtkProbe` didn’t produce nonzero output.