Threshold of vtkPolyData with vtkLines

Hi all,

I have generated a dataset similar to this example: but with multiple point data arrays in the dataset as well.

I can open the file in Paraview and it displays all of the arrays perfectly. The information tab shows 11804 cells and 11805 points. I want to then threshold the line to where an array is greater than a certain value, however this causes nothing to be displayed, and the information tab shows 0 points and 0 cells. The only work around I have managed is by adding the Point Data to Cell Data filter and then thresholding off the cell data. Is there a better way of doing this while preserving the point data attribute?