[vtkusers] about vtkMarchingCubes

Mathieu Malaterre mathieu.malaterre at kitware.com
Thu Apr 29 12:58:49 EDT 2004 

Vetria,

	[You should change the subject of your mail to reflect the topic of 
your question, thanks]

	I believe you can do:

actor.SetBackfaceProperty( vtk.vtkProperty() )
actor.GetBackfaceProperty().SetColor(1,0,0)

HTH
Mathieu

Vetria Byrd wrote:
> I want to show which vertices are found to be inside and outside the object
> by displaying those vertices and edges in different colors:  red (inside)
> and blue (outside).
> 
> How do I do this?
> 
> Thanks,
> Vetria
> 
> -----Original Message-----
> From: vtkusers-admin at vtk.org [mailto:vtkusers-admin at vtk.org] On Behalf Of
> Vetria Byrd
> Sent: Wednesday, April 28, 2004 8:49 AM
> To: 'Mathieu Malaterre'
> Cc: vtkusers at vtk.org
> Subject: RE: [vtkusers] about vtkMarchingCubes
> 
> Mathieu,
> 
> Thanks for all of your help.
> Vetria
> 
> -----Original Message-----
> From: Mathieu Malaterre [mailto:mathieu.malaterre at kitware.com] 
> Sent: Tuesday, April 27, 2004 2:41 PM
> To: byrdv at cis.uab.edu
> Cc: vtkusers at vtk.org
> Subject: Re: [vtkusers] about vtkMarchingCubes
> 
> Vetria,
> 
> 	Your code is /almost/ perfect, so the problem comes from your files.
> 
> When using vtkImageReader2 you should use
> 
> 	SetDataExtent(0,5,0,5,0,5);
> 
> Otherwise your extent will be different...obviously, as you want a 5x5x5 
> picture. Anyway I included a c++ code that show you how to achieve what 
> you are looking for. You can play with this code and write the 
> vtkIamgeData using vtkImageWriter and then load that file again using 
> vtkImageReader2 + proper SetDataExtent and you'll see it will work.
> 
> HTH
> Mathieu
> Ps: For god sake, please avoid static cast like:
> 
>     objExtractor->SetInput((vtkDataSet *) volReader->GetOutput() );
> 
> instead do #include "vtkDataSet.h" top of your c++ file.
> 
> 
> Vetria Byrd wrote:
> 
>>Here's the code (please see note after code):
>>
>> 
>>
>>vtkRenderer *ren = vtkRenderer::New();
>>
>>  vtkRenderWindow *renWin = vtkRenderWindow::New();
>>
>>    renWin->AddRenderer(ren);
>>
>>  vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
>>
>>    iren->SetRenderWindow(renWin);
>>
>> 
>>
>>  vtkImageReader2 *volReader = vtkImageReader2::New();
>>
>>      volReader->SetDataOrigin(0.0,0.0,0.0);
>>
>>    volReader->SetDataExtent(0,6,0,5,0,5);
>>
>>      volReader->SetDataByteOrderToLittleEndian();
>>
>>      volReader->SetFilePrefix("C:/src/VolumeData/slice");
>>
>> 
>>
>>    volReader->SetDataSpacing(1,1,1);
>>
>>    volReader->Update();
>>
>> 
>>
>>  vtkMarchingCubes *iso = vtkMarchingCubes::New();
>>
>>     iso->SetInput(volReader->GetOutput() );
>>
>>       iso->SetValue(0,0.5);
>>
>> 
>>
>>  vtkContourFilter *objExtractor = vtkContourFilter::New();
>>
>>    objExtractor->SetInput((vtkDataSet *) volReader->GetOutput() );
>>
>>      objExtractor->SetValue(0,0.5);
>>
>>       
>>
>>  vtkPolyDataNormals *isoNormals = vtkPolyDataNormals::New();
>>
>>    isoNormals->SetInput(iso->GetOutput());
>>
>>    isoNormals->SetFeatureAngle(60.0);
>>
>> 
>>
>>  vtkStripper *objStripper = vtkStripper::New();
>>
>>    objStripper->SetInput(isoNormals->GetOutput());
>>
>>     
>>
>>  vtkPolyDataMapper *isoMapper = vtkPolyDataMapper::New();
>>
>>      isoMapper->SetInput(objStripper->GetOutput() );
>>
>>        //isoMapper->SetInput(isoNormals->GetOutput() );
>>
>>      isoMapper->ScalarVisibilityOff();
>>
>> 
>>
>>  vtkActor *isoActor = vtkActor::New();
>>
>>      isoActor->SetMapper(isoMapper);
>>
>> 
>>
>>  // An outline provides context around the data.
>>
>>  vtkOutlineFilter *outlineData = vtkOutlineFilter::New();
>>
>>    outlineData->SetInput((vtkDataSet *) volReader->GetOutput());
>>
>>  vtkPolyDataMapper *mapOutline = vtkPolyDataMapper::New();
>>
>>    mapOutline->SetInput(outlineData->GetOutput());
>>
>>  vtkActor *outline = vtkActor::New();
>>
>>    outline->SetMapper(mapOutline);
>>
>>    outline->GetProperty()->SetColor(0,0,0);
>>
>>       
>>
>>   // Add the actors to the renderer, set the background and size
>>
>>   ren->AddActor(outline);
>>
>>   ren->AddActor(isoActor);
>>
>>  
>>
>>   ren->SetBackground(1,1,1); 
>>
>>   renWin->SetSize(450,450);
>>
>>  
>>
>>   iren->Initialize();
>>
>>  
>>
>>   // render the image
>>
>>   iren->Start();
>>
>> 
>>
>> 
>>
>>Note:  when I change volReader->SetDataExtent(0,6,0,5,0,5); to
>>
>>volReader->SetDataExtent(0,5,0,5,0,5);
>>
>>I get this:
>>
>> 
>>
>>-----Original Message-----
>>From: Mathieu Malaterre [mailto:mathieu.malaterre at kitware.com]
>>Sent: Tuesday, April 27, 2004 11:54 AM
>>To: byrdv at cis.uab.edu
>>Cc: vtkusers at vtk.org
>>Subject: Re: [vtkusers] about vtkMarchingCubes
>>
>> 
>>
>>Vetria,
>>
>> 
>>
>>      Could you send us the c++ demo file you are using, I suspect you are
>>
>>reading your file improperly (data extent is wrong).
>>
>> 
>>
>>Thanks
>>
>>Mathieu
>>
>> 
>>
>>Vetria Byrd wrote:
>>
>>
>>> In the data files slices 0,1,3,4 and 5 contain all zero's.
>>
>>> In slice 2, cell [2][2][2] = 1 all other cell values are zero's.
>>
>>> Vetria
>>
>>> -----Original Message-----
>>
>>> From: Mathieu Malaterre [mailto:mathieu.malaterre at kitware.com]
>>
>>> Sent: Tuesday, April 27, 2004 10:50 AM
>>
>>> To: byrdv at cis.uab.edu
>>
>>> Cc: vtkusers at vtk.org
>>
>>> Subject: Re: [vtkusers] about vtkMarchingCubes
>>
>>> Vetria,
>>
>>>      Can you send us a screenshot of your problem ?
>>
>>> Thanks
>>
>>> Mathieu
>>
>>> Vetria Byrd wrote:
>>
>>>> The dataset consists of 5 files/slices, all containing zero's and
> 
> one's.
> 
>>>> The goal is to take a 5x5x5 volume that contains an object in the
> 
> center
> 
>>>> cell and extract that object.
>>
>>>> Data Spacing is set to:  volReader->SetDataSpacing(1,1,1);
>>
>>>> Thanks,
>>
>>>> Vetria
>>
>>>> -----Original Message-----
>>
>>>> From: Mathieu Malaterre [mailto:mathieu.malaterre at kitware.com]
>>
>>>> Sent: Monday, April 26, 2004 5:26 PM
>>
>>>> To: Vetria Byrd
>>
>>>> Cc: vtkusers at vtk.org
>>
>>>> Subject: Re: [vtkusers] about vtkMarchingCubes
>>
>>>> Vetria,
>>
>>>>     What type of image are you reading ? Is it possible that you have
> 
> a
> 
>>>> negative spacing ? You might to avoid this.
>>
>>>> HTH
>>
>>>> Mathieu
>>
>>>> Vetria Byrd wrote:
>>
>>>>>I am having a similiar problem with vtkMarchingCubes as posted at
>>
>>>>>http://public.kitware.com/pipermail/vtkusers/2003-March/017033.html
>>
>>>>>but I have not been able to find the reply or answer to the problem.
>>
>>>>>I am reading several data files and using vtkMarchingCubes to 
>>
>>display the
>>
>>
>>>>>reconstructed object, but the positioning of the rendered object 
>>
>>seems to
>>
>>
>>>>>be off.  It shoud be centered within the view but no matter what I 
>>
>>do it's
>>
>>
>>>>>always off center.
>>
>>>>>Can anyone give me an idea of what could be causing this?
>>
>>>>>Thank you,
>>
>>>>>Vetria
>>
>>>>>_______________________________________________
>>
>>>>>This is the private VTK discussion list.
>>
>>>>>Please keep messages on-topic. Check the FAQ at:
>>
>>>> <http://public.kitware.com/cgi-bin/vtkfaq>
>>
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>>
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>>
>> 
>>
> 
> 
> 
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