[vtkusers] string labels on cellcenters

[Vidyadhar]

The documentation for vtkLabeledDataMapper works only with dataset points. 
As I understand it this means it can only use PointData and not CellData. 
May be somebody will correct me.
Vidyadhar
----- Original Message ----- 
From: "Raphael Walker" <web at busino.ch>
To: <vtkusers at vtk.org>
Sent: Wednesday, October 17, 2007 5:14 PM
Subject: [vtkusers] string labels on cellcenters


> Hi all,
>
> I'm trying to have string labels on cell centers of a unstructuredgrid 
> plot.
>
> 1. first i create a vtkCharArray with the strings.
> 2. add it to the cell data
> 3. create a vtkLabeledDataMapper with the cellcenter
> 4. set the fieldDataArray
>
> I only get "(null)" labels!
>
> For an example see the script at the end.
>
> Thanks for any help and ideas
>
> Raffs
>
>
>
> EXAMPLE++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
> #!/usr/bin/env python
>
> import vtk
>
> from vtk import *
> from numpy import *
>
> #
> # array to create the model
> #
>
> # points coordinates
> ptarray = 
> array([0,0,0,0,0.153135,0,0.358,0.153135,0,0.358,0,0,0.0770633,0,0,0.19452,0,0,0.288133,0,0,0,0.0768721,0,0.0766132,0.153135,0,0.191553,0.153135,0,0.270763,0.153135,0,0.358,0.0697678,0,0.267349,0.0919374,0,0.134156,0.0780027,0])
> # element table
> earray = 
> array([3,3,11,6,3,6,11,12,3,10,9,12,3,9,8,13,3,12,9,13,3,8,1,7,3,13,8,7,3,7,0,4,3,13,7,4,3,4,5,13,3,5,6,12,3,13,5,12,3,11,2,12,3,2,10,12], 
> int32)
> # element types -> triangle
> ctarray  = array((6,6,6,6,6,6,6,6,6,6,6,6,6,6), ubyte)
> # element start index
> locarray = array((0,4,8,12,16,20,24,28,32,36,40,44,48,52), int32)
> # scalar values for the cell centers
> scalarray = array((1.,2.,3.,4.,5.,6.,7.,8.,9.,8.,7.,6.,5.,4.))
> # label array
> labelarray = array(("QW", "SD", "sd", "qe", "gd", "sd", "qe", "fd", "sd", 
> "we", "gd", "ad", "qe", "gd"))
>
> # idtypes
> IdTArray=vtkIdTypeArray()
> IdTArray.SetNumberOfComponents(3)
> IdTArray.SetNumberOfTuples(len(earray))
> IdTArray.SetVoidArray(earray,len(earray),1)
> # celltypes
> cidTArray=vtkUnsignedCharArray()
> cidTArray.SetVoidArray(ctarray,len(ctarray),1)
> # cell array
> vtkCArray=vtkCellArray()
> vtkCArray.SetCells(len(earray),IdTArray)
> # cell location
> vtkLocArray=vtkIdTypeArray()
> vtkLocArray.SetVoidArray(locarray,len(locarray),1)
> # grid
> grid=vtkUnstructuredGrid()
> grid.SetCells(cidTArray,vtkLocArray,vtkCArray)
>
> # points
> vpoints=vtkDoubleArray()
> vpoints.SetNumberOfComponents(3)
> vpoints.SetNumberOfTuples(len(ptarray))
> vpoints.SetVoidArray(ptarray,len(ptarray),1)
> pointe = vtkPoints()
> pointe.SetData(vpoints)
> grid.SetPoints(pointe)
> grid.Update()
>
> # scalars
> scalars = vtkDoubleArray()
> scalars.SetVoidArray(scalarray, len(scalarray), 1)
> grid.GetCellData().SetScalars(scalars)
>
> # labels
> charArray = vtkCharArray()
> charArray.SetNumberOfComponents(3)
> charArray.SetNumberOfTuples(len(labelarray))
> charArray.SetVoidArray(labelarray, 3*14,1)
> grid.GetCellData().AddArray(charArray)
>
> geom = vtkGeometryFilter()
> geom.SetInput(grid)
>
> # Create cell centers
> cellCenters = vtk.vtkCellCenters()
> cellCenters.SetInputConnection(geom.GetOutputPort())
>
> # Create the mapper to display the cell
> cellMapper = vtk.vtkLabeledDataMapper()
> cellMapper.SetInputConnection(cellCenters.GetOutputPort())
> cellMapper.SetLabelFormat("%s")
> cellMapper.SetLabelModeToLabelFieldData()
> #cellMapper.TreatCharDataAsStringOn();
> cellMapper.SetFieldDataArray(0)
>
> # actor for the labels
> labelActor = vtk.vtkActor2D()
> labelActor.SetMapper(cellMapper)
>
> # data color mapper
> ColorMapper=vtkPolyDataMapper()
> ColorMapper.SetInputConnection(geom.GetOutputPort())
> ColorMapper.SetScalarModeToUseCellData()
> ColorMapper.SetScalarRange(0.,9.)
>
> # actor for the colors
> colorActor = vtkActor()
> colorActor.SetMapper(ColorMapper)
>
>
> # renderer
> ren = vtk.vtkRenderer()
>
> # render window
> win = vtkRenderWindow()
>
> iren = vtkRenderWindowInteractor()
> iren.SetRenderWindow(win)
> style = vtkInteractorStyleTrackballCamera()
> iren.SetInteractorStyle(style)
> iren.Initialize()
>
> win.AddRenderer(ren)
> ren.AddActor(colorActor)
> ren.AddActor(labelActor)
>
> ren.SetBackground(0.1, 0.3, 0.4)
> win.Render()
> iren.Start()
>
>