MantisBT - VTK
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IDProjectCategoryView StatusDate SubmittedLast Update
0000564VTK(No Category)public2004-02-02 05:032016-08-12 09:54
ReporterSander Niemeijer 
Assigned ToWill Schroeder 
PrioritynormalSeveritymajorReproducibilityalways
StatusclosedResolutionmoved 
PlatformOSOS Version
Product Version 
Target VersionFixed in Version 
Project
Type
Summary0000564: vtkPolyData + vtkCellData + multiple cell types
DescriptionWhen using a combination of cell types within a vtkPolyData object (i.e. both vertices, lines, polys, and/or strips) the cell data property of the vtkPolyData object does not get handled properly (there is no fixed relation between the cell ids of the vtkCellData object and the cell ids of the vtkPolyData object). Furthermore, the polydata mappers are also not consistent in how they deal with the CellData of a vtkPolyData object when the cell data is used for coloring information.

The python code below illustrates the problem:
If things would be correct you should see a red triangle, a green line, and a blue bar. But both the vtkPolyDataMapper and vtkPolyDataMapper2D give different results.

-----
import vtk

VTK_LINE = 3
VTK_POLYGON = 7

# initialize polydata object
polydata = vtk.vtkPolyData()
polydata.SetLines(vtk.vtkCellArray())
polydata.SetPolys(vtk.vtkCellArray())

points = vtk.vtkPoints()
# points for poly 1 (triangle)
points.InsertNextPoint(0.2, 0.3, 0)
points.InsertNextPoint(0.4, 0.55, 0)
points.InsertNextPoint(0.2, 0.8, 0)
# points for line 1 (line)
points.InsertNextPoint(0.5, 0.3, 0)
points.InsertNextPoint(0.5, 0.8, 0)
# points for poly 2 (bar)
points.InsertNextPoint(0.6, 0.3, 0)
points.InsertNextPoint(0.8, 0.3, 0)
points.InsertNextPoint(0.8, 0.8, 0)
points.InsertNextPoint(0.6, 0.8, 0)
polydata.SetPoints(points)

# set scalar cell data
colors = vtk.vtkFloatArray()
polydata.GetCellData().SetScalars(colors)

# create poly 1
ids = vtk.vtkIdList()
ids.InsertNextId(0)
ids.InsertNextId(1)
ids.InsertNextId(2)
cell = polydata.InsertNextCell(VTK_POLYGON, ids)
# poly 1 should get the first color (red)
colors.InsertTuple1(cell, 0.0)

# create line 1
ids.Reset()
ids.InsertNextId(3)
ids.InsertNextId(4)
cell = polydata.InsertNextCell(VTK_LINE, ids)
# line 1 should get the second color (green)
colors.InsertTuple1(cell, 1.0)

# create poly 2
ids.Reset()
ids.InsertNextId(5)
ids.InsertNextId(6)
ids.InsertNextId(7)
ids.InsertNextId(8)
cell = polydata.InsertNextCell(VTK_POLYGON, ids)
# poly 2 should get the third color (blue)
colors.InsertTuple1(cell, 2.0)

# create reference poly with colors as they should be
refpoly = vtk.vtkPolyData()
refpoly.SetLines(vtk.vtkCellArray())
refpoly.GetCellData().SetScalars(colors)
scalars = refpoly.GetCellData().GetScalars()
print scalars.GetNumberOfTuples()
refpoints = vtk.vtkPoints()
refpoints.InsertNextPoint(0.2, 0.2, 0)
refpoints.InsertNextPoint(0.4, 0.2, 0)
refpoints.InsertNextPoint(0.6, 0.2, 0)
refpoints.InsertNextPoint(0.8, 0.2, 0)
refpoly.SetPoints(refpoints)
ids.Reset()
ids.InsertNextId(0)
ids.InsertNextId(1)
cell = refpoly.InsertNextCell(VTK_LINE, ids)
ids.Reset()
ids.InsertNextId(1)
ids.InsertNextId(2)
cell = refpoly.InsertNextCell(VTK_LINE, ids)
ids.Reset()
ids.InsertNextId(2)
ids.InsertNextId(3)
cell = refpoly.InsertNextCell(VTK_LINE, ids)

# define colors
lut = vtk.vtkLookupTable()
lut.SetNumberOfTableValues(3)
lut.SetTableRange(0, 2)
lut.SetTableValue(0, 1.0, 0.0, 0.0, 1.0) # red
lut.SetTableValue(1, 0.0, 1.0, 0.0, 1.0) # green
lut.SetTableValue(2, 0.0, 0.0, 1.0, 1.0) # blue
lut.Build()

# create mapper and assign colortable
polyMapper = vtk.vtkPolyDataMapper()
polyMapper.SetInput(polydata)
polyMapper.SetScalarModeToUseCellData()
polyMapper.UseLookupTableScalarRangeOn()
polyMapper.SetLookupTable(lut)
coordinate = vtk.vtkCoordinate()
coordinate.SetCoordinateSystemToNormalizedViewport()
polyMapper2D = vtk.vtkPolyDataMapper2D()
polyMapper2D.SetTransformCoordinate(coordinate)
polyMapper2D.SetInput(polydata)
polyMapper2D.SetScalarModeToUseCellData()
polyMapper2D.UseLookupTableScalarRangeOn()
polyMapper2D.SetLookupTable(lut)

# same for the refpoly
refpolyMapper = vtk.vtkPolyDataMapper()
refpolyMapper.SetInput(refpoly)
refpolyMapper.SetScalarModeToUseCellData()
refpolyMapper.UseLookupTableScalarRangeOn()
refpolyMapper.SetLookupTable(lut)
refpolyMapper2D = vtk.vtkPolyDataMapper2D()
refpolyMapper2D.SetTransformCoordinate(coordinate)
refpolyMapper2D.SetInput(refpoly)
refpolyMapper2D.SetScalarModeToUseCellData()
refpolyMapper2D.UseLookupTableScalarRangeOn()
refpolyMapper.SetLookupTable(lut)
refpolyMapper2D.SetLookupTable(lut)

# create actors
polyActor = vtk.vtkActor()
polyActor.SetMapper(polyMapper)
polyActor2D = vtk.vtkActor2D()
polyActor2D.SetMapper(polyMapper2D)
refpolyActor = vtk.vtkActor()
refpolyActor.SetMapper(refpolyMapper)
refpolyActor2D = vtk.vtkActor2D()
refpolyActor2D.SetMapper(refpolyMapper2D)

# create renderers
renderer = vtk.vtkRenderer()
renderer.SetViewport(0, 0, 0.5, 1.0)
renderer.AddActor(polyActor)
renderer.AddActor(refpolyActor)
renderer2D = vtk.vtkRenderer()
renderer2D.SetViewport(0.5, 0.0, 1.0, 1.0)
renderer2D.AddActor(polyActor2D)
renderer2D.AddActor(refpolyActor2D)

# render it
renderWindow = vtk.vtkRenderWindow()
renderWindow.SetSize(600,300)
renderWindow.AddRenderer(renderer)
renderWindow.AddRenderer(renderer2D)
iren = vtk.vtkRenderWindowInteractor()
iren.SetRenderWindow(renderWindow)
renderWindow.Render()
iren.Start()
Steps To Reproduce
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Issue History
Date ModifiedUsernameFieldChange
2011-06-16 13:11Zack GalbreathCategory => (No Category)
2016-08-12 09:54Kitware RobotNote Added: 0036711
2016-08-12 09:54Kitware RobotStatusexpired => closed
2016-08-12 09:54Kitware RobotResolutionopen => moved

Notes
(0036711)
Kitware Robot   
2016-08-12 09:54   
Resolving issue as `moved`.

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