[Paraview] Problem with vtkStringData in Composite dataset

[Jan Brezina]

Dear paraview users,

I have a MultiBlock Dataset
containing a single leaf (vktPolyData) with PointData having a
vtkStringArray named "labels". I try to display these labels selection
the block and setting label format "%s". This approach works if
that leaf block is treated out of the composite dataset, but within
composite dataset I get a warning:

Warning: In
/home/kitware/Dashboards/MyTests/NightlyMaster/ParaViewSuperbuild-Release/paraview/src/paraview/VTK/Rendering/Label/vtkLabeledDataMapper.cxx,
line 442
vtkLabeledDataMapper (0x597e640): Could not find label array (labels) in
input.

and no labels are shown.

Then I tried to use ExtractBlock + MergeBlocks and apply selection
there, but MergeBlocks simply drops the "labels" array.

Is it an error or should I do something special to make such  an
AbstractArray work.

Below you find a ProgrammableSource script to generate a sample
MultiblockDataset for reproduction of the problem. Here I set "labels"
array to all leaf blocks with the same result.

Thank you for help

Jan

=============================
import vtk

def make_rect(coords):
    xmin,ymin,xmax,ymax=coords

    pts = vtk.vtkPoints()
    pts.InsertPoint(0, xmin, ymin, 0)
    pts.InsertPoint(1, xmax, ymin, 0)
    pts.InsertPoint(2, xmax, ymax, 0)
    pts.InsertPoint(3, xmin, ymax, 0)
    rect = vtk.vtkCellArray()
    rect.InsertNextCell(5)
    rect.InsertCellPoint(0)
    rect.InsertCellPoint(1)
    rect.InsertCellPoint(2)
    rect.InsertCellPoint(3)
    rect.InsertCellPoint(0)

    output = vtk.vtkPolyData()
    output.SetPoints(pts)
    output.SetLines(rect)

    labels=vtk.vtkStringArray()
    labels.InsertNextValue("one")
    labels.InsertNextValue("two")
    labels.InsertNextValue("three")
    labels.InsertNextValue("four")
    labels.SetName("labels")
    output.GetPointData().AddArray(labels)

    tenths=vtk.vtkIntArray()
    tenths.InsertNextValue(10)
    tenths.InsertNextValue(20)
    tenths.InsertNextValue(30)
    tenths.InsertNextValue(40)
    tenths.SetName("tenths")
    output.GetPointData().AddArray(tenths)

    return output

output.SetBlock(0, make_rect( (0,0,1,1) ) )
output.SetBlock(1, make_rect( (1,1,2,2) ) )
which




-- 
------------------------
Mgr. Jan Brezina, Ph. D.
Technical University in Liberec, New technologies institute
http://www.nti.tul.cz/cz/WikiUser:Jan.Brezina