[vtkusers] marching cubes output

[Vetria Byrd]

I have written a program to extract data from 2D slices of data files.

Five data files were manually created.  Each of the data files look like
this:

 

0 0 0 0 0

0 0 0 0 0

0 0 1 0 0

0 0 1 0 0

0 0 0 0 0

0 0 0 0 0

 

Where the 0's indicate the object is outside the cube and 1 indicates the
object is inside the cube.

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 1st figure.  Viewing the wire frame
display (2nd figure) shows the 5x5x5 grid with an unexpected dip in the top
row.

 



 

I am missing something, I just don't know what that "something" is.

What I want the algorithm to do is render the object based on which values
of the data indicate the object is present.

 

Here's the code:

//

// This example reads a volume dataset, extracts an isosurface and displays
it.

//

 

#include "vtkRenderer.h"

#include "vtkRenderWindow.h"

#include "vtkRenderWindowInteractor.h"

#include "vtkVolumeReader.h"

#include "vtkImageReader2.h"

#include "vtkMarchingCubes.h"

#include "vtkPolyDataMapper.h"

#include "vtkActor.h"

#include "vtkOutlineFilter.h"

#include "vtkCamera.h"

#include "vtkProperty.h"

#include "vtkPolyDataNormals.h"

#include "vtkContourFilter.h"

 

int main ()

{

  

  vtkRenderer *ren = vtkRenderer::New();

  vtkRenderWindow *renWin = vtkRenderWindow::New();

    renWin->AddRenderer(ren);

  vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();

    iren->SetRenderWindow(renWin);

 

  vtkImageReader2 *volReader = vtkImageReader2::New();

  volReader->SetDataExtent(0,5,0,5,0,5);

  volReader->SetFilePrefix("C:/data/cube/slice");

  volReader->SetDataSpacing(1,1,1);

  volReader->Update();

 

    

  // An isosurface, or contour value of 1 is known to correspond to the

  // object

  vtkMarchingCubes *iso =vtkMarchingCubes::New();

     iso->SetInput(volReader->GetOutput() );

     iso->SetValue(0,1);  

 

  vtkPolyDataMapper *isoMapper = vtkPolyDataMapper::New();

      isoMapper->SetInput(iso->GetOutput() );

             

  vtkActor *isoActor = vtkActor::New();

      isoActor->SetMapper(isoMapper);

  

  vtkOutlineFilter *outline = vtkOutlineFilter::New();

      outline->SetInput( (vtkDataSet *) volReader->GetOutput() );

     

   vtkPolyDataMapper *outlineMapper = vtkPolyDataMapper::New();

      outlineMapper->SetInput(outline->GetOutput() );

   

   vtkActor *outlineActor = vtkActor::New();

      outlineActor->SetMapper(outlineMapper);

      outlineActor->VisibilityOff();

      

   //

   // Add the actors to the renderer, set the background and size

   //

   ren->AddActor(outlineActor);

   ren->AddActor(isoActor);

   ren->SetBackground(0.2,0.3,0.4);

   renWin->SetSize(450,450);

   ren->GetActiveCamera()->Elevation(90);

   ren->GetActiveCamera()->SetViewUp(0,0,-1);

   

   iren->Initialize();

   

   // render the image

   iren->Start();

   

 

   return 0;

}

 

Thanks.

_______________

Vetria L. Byrd

 

 

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