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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>John,</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>When I changed to volReader->SetDataExtent(04,05,04)
nothing is rendered.</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I got the iso->SetValue(0,1) from the
Medical1, 2 and 3 example code where the 1 is supposed to correspond to the
object.</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks,</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Vetria</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'>-----Original Message-----<br>
<b><span style='font-weight:bold'>From:</span></b> vtkusers-admin@vtk.org
[mailto:vtkusers-admin@vtk.org] <b><span style='font-weight:bold'>On Behalf Of </span></b>anast.jm@pg.com<br>
<b><span style='font-weight:bold'>Sent:</span></b> </span></font><font size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>Wednesday,
April 07, 2004</span></font><font size=2 face=Tahoma><span style='font-size:
10.0pt;font-family:Tahoma'> </span></font><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'>3:47 PM</span></font><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'><br>
<b><span style='font-weight:bold'>To:</span></b> </span></font><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>vtkusers@vtk.org</span></font><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [vtkusers] marching
cubes output</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-right:0in;margin-bottom:12.0pt;margin-left:
.5in'><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><br>
</span></font><font size=2 face=sans-serif><span style='font-size:10.0pt;
font-family:sans-serif'>From your description, your dataset seems to be 5x6x5
but your coded data extent is 6x6x6...I'm suprised this didn't generate an
error.</span></font> <br>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>volReader->SetDataExtent(0,5,0,5,0,5);</span></font>
<br>
<br>
<br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>also
I'm a bit rusty on marching cubes but don't you need a value between 0 and 1 to
create the isosurface you are after??</span></font> <br>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>iso->SetValue(0,1);</span></font>
<br>
<br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>....john</span></font>
<br>
<br>
<br>
<br>
</p>
<table class=MsoNormalTable border=0 cellpadding=0 width="100%"
style='width:100.0%;margin-left:.5in'>
<tr>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
</td>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><b><font size=1 face=sans-serif><span style='font-size:
7.5pt;font-family:sans-serif;font-weight:bold'>"Vetria Byrd"
<byrdv@cis.uab.edu></span></font></b> <br>
<font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>Sent
by: vtkusers-admin@vtk.org</span></font> </p>
<p><font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:
sans-serif'>04/07/2004 04:05 PM</span></font> <br>
<font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>Please
respond to byrdv</span></font> </p>
</td>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><font size=1 face=Arial><span style='font-size:7.5pt;
font-family:Arial'> </span></font><br>
<font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>
To: <vtkusers@vtk.org></span></font>
<br>
<font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>
cc: (bcc: John Anast-JM/PGI)</span></font>
<br>
<font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>
Subject: [vtkusers] marching
cubes output</span></font></p>
</td>
</tr>
</table>
<p class=MsoNormal style='margin-right:0in;margin-bottom:12.0pt;margin-left:
.5in'><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><br>
<br>
<br>
</span></font><font size=2 face=Arial><span style='font-size:10.0pt;font-family:
Arial'>I have written a program to extract data from 2D slices of data files.</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Five
data files were manually created. Each of the data files look like this:</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>0 0 0
0 0</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>0 0 0
0 0</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>0 0 1
0 0</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>0 0 1
0 0</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>0 0 0
0 0</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>0 0 0
0 0</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Where
the 0's indicate the object is outside the cube and 1 indicates the object is
inside the cube.</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>When I
run the program (which compiles and runs with no problems) I expected to get a
solid object representing the center of the 5x5x5 rendered object since only
the center values of the data (input) show that the object is inside but what I
get is shown in the 1<sup>st</sup> figure. Viewing the wire frame display
(2<sup>nd</sup> figure) shows the 5x5x5 grid with an unexpected dip in the top
row.</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>I am
missing something, I just don't know what that "something" is.</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>What I
want the algorithm to do is render the object based on which values of the data
indicate the object is present.</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Here's
the code:</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>//</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>//
This example reads a volume dataset, extracts an isosurface and displays it.</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>//</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkRenderer.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkRenderWindow.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkRenderWindowInteractor.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkVolumeReader.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkImageReader2.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkMarchingCubes.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkPolyDataMapper.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkActor.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkOutlineFilter.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkCamera.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkProperty.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkPolyDataNormals.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>#include
"vtkContourFilter.h"</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>int
main ()</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>{</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font><br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkRenderer *ren = vtkRenderer::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkRenderWindow *renWin = vtkRenderWindow::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
renWin->AddRenderer(ren);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
iren->SetRenderWindow(renWin);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkImageReader2 *volReader = vtkImageReader2::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
volReader->SetDataExtent(0,5,0,5,0,5);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
volReader->SetFilePrefix("C:/data/cube/slice");</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
volReader->SetDataSpacing(1,1,1);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
volReader->Update();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font><br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
// An isosurface, or contour value of 1 is known to correspond to the</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
// object</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkMarchingCubes *iso =vtkMarchingCubes::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
iso->SetInput(volReader->GetOutput() );</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
iso->SetValue(0,1); </span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkPolyDataMapper *isoMapper = vtkPolyDataMapper::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
isoMapper->SetInput(iso->GetOutput() );</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkActor *isoActor = vtkActor::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
isoActor->SetMapper(isoMapper);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font><br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkOutlineFilter *outline = vtkOutlineFilter::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
outline->SetInput( (vtkDataSet *) volReader->GetOutput() );</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkPolyDataMapper *outlineMapper = vtkPolyDataMapper::New();</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
outlineMapper->SetInput(outline->GetOutput() );</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
vtkActor *outlineActor = vtkActor::New();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
outlineActor->SetMapper(outlineMapper);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
outlineActor->VisibilityOff();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font><br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
//</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
// Add the actors to the renderer, set the background and size</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
//</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
ren->AddActor(outlineActor);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
ren->AddActor(isoActor);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
ren->SetBackground(0.2,0.3,0.4);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
renWin->SetSize(450,450);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
ren->GetActiveCamera()->Elevation(90);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
ren->GetActiveCamera()->SetViewUp(0,0,-1);</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
iren->Initialize();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
// render the image</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
iren->Start();</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>
return 0;</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>}</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Thanks.</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>_______________</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Vetria
L. Byrd</span></font> <br>
<br>
</p>
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