vtkImplicitVolume/colorlookup/grayscale image

[Dr. Jasjit Suri]

Hello..

I guess those who deal with volumes can tell me something on this...

1) I take the VOI and extract the plane i wish using vtkPlaneSource
   in part 1 of the code attached...

2) Now i define the implicit Function using vtkImplicitVolume
    and pass that to the vtkClipPolyData.

This will snap the gray scale image on the cut section.

I wish to know why i cannot get the original gray scale
image even though i adjust the colorlookuptable
for the 8 bit data...

Is it that the color look up table does not work when
the clip function is the implicit volume ?

I tried every way to adjust the parameters
but i cannot get the gray scale image ?

But i use the pipeline:

vtkPlaneSource->vtkTransformPolyDataFilter-->
vtkProbeFilter-->vtkCastToConcrete-->vtkTriangleFilter-->
vtkSTripper-->vtkLookupTable-->vtkPolyDataMapper-->
vtkActor-->AddActor,  T H E N,
I am able to get the gray sale image. fine...


Here is the code which uses vtkImplicitVolume :
--------------------------------

# part1 : get the plane source from the VOI
vtkExtractVOI aPlaneSection
   aPlaneSection SetVOI $centerX $centerX 0 $endZ 0 $endY
   aPlaneSection SetInput [reader GetOutput]
   aPlaneSection Update

set bounds [[aPlaneSection GetOutput] GetBounds]

vtkPlaneSource aPlaneSource
aPlaneSource SetOrigin [lindex $bounds 0] [lindex $bounds 2] [lindex
$bounds 4]
aPlaneSource SetPoint1 [lindex $bounds 0] [lindex $bounds 2] [lindex
$bounds 5]
aPlaneSource SetPoint2 [lindex $bounds 0] [lindex $bounds 3] [lindex
$bounds 4]
aPlaneSource SetResolution 200 100
# --------------------------------------------------------
# part 2
vtkImplicitVolume aVolumeModel
  aVolumeModel SetVolume [SP GetOutput]

# clip the polydata
set iso_levelB 40.0
vtkClipPolyData clipperB
  clipperB SetInput [aPlaneSource GetOutput]
  clipperB SetClipFunction aVolumeModel
  clipperB SetValue $iso_levelB
  clipperB GenerateClipScalarsOn
  clipperB Update


set  win_value 255
set  win_level 127
set  table_range 255

vtkLookupTable cLUT
   cLUT SetHueRange 0.0 1.0
   cLUT SetNumberOfColors 256
   cLUT SetTableRange 0 255
   cLUT SetSaturationRange 0 0
   cLUT SetValueRange 0 1
   cLUT SetAlphaRange 1 1
   cLUT Build

set scalar_range 40.0
vtkPolyDataMapper aClipperMapperB
  aClipperMapperB SetInput [clipperB GetOutput]
  aClipperMapperB SetScalarRange 0 $scalar_range
  aClipperMapperB ScalarVisibilityOff
  aClipperMapperB SetLookupTable cLUT

vtkActor cut
  cut SetMapper aClipperMapperB

ren AddActor cut
------------------------------------------



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