Sort points on line in PolyData

Support
#1

So I have a PolyData object of lines generated from extracting feature edges from a 2D unstructured grid and then cutting out portions of the feature edges I didn’t want.

In my example, the original grid was just a square, so the feature edges would equally just be a square. Then I “extracted” out one side of the square. I would like to have the points of this PolyData object be in the order of the line, as currently they are more-or-less random.

From this definition on the VTK examples website, maybe the solution would be to convert the PolyData to a PolyLine? I can’t find any obvious path to achieve this though.

#2

You can use vtkStripper to merge randomly ordered line segments into polylines. If the polydata is large then you may need to increase MaximumLength.

#3

So this does work, but it has the unintended effect of combining the individual cells into single lines. ie.

wallpoly.GetNumberOfCells() # 1246

strip = vtk.vtkStripper()
strip.SetInputData(wallpoly.GetOutput())
strip.Update()
wallstrip = strip.GetOutput()

wallstrip.GetNumberOfCells() # 2

I tried setting strip.SetJoinContiguousSegments(False), but this did not change anything. It’s not a deal breaker by any means, but it would be nice to preserve the cells/lines.