[vtkusers] some questions about cells, file formats, etc

[David Doria]

On Wed, Jan 11, 2012 at 3:04 PM, nuno.jf <nunofernandes7 at gmail.com> wrote:
> Sure, and thank you for your help!
> Sorry for some confusion in my code:
> (Btw, I noticed that When I set mc->ComputeNormalsOff() instead of
> mc->ComputeNormalsOn() , I don't get this error)
>
>
>
> // Includes for lots of things
> //VTK
> #include "vtkSmartPointer.h"
> #include "vtkPolyData.h"
> #include "vtkPolyDataReader.h"
> #include "vtkStructuredPointsReader.h"
> #include "vtkMarchingCubes.h"
> #include "vtkImageMarchingCubes.h"
> #include "vtkGaussianSplatter.h"
> #include "vtkImageGaussianSmooth.h"
> #include "vtkPolyDataConnectivityFilter.h"
> #include "vtkContourFilter.h"
> #include "vtkGaussianSplatter.h"
> #include "vtkPolyDataWriter.h"
> #include "vtkGeometryFilter.h"
> #include "vtkStructuredPoints.h"
> #include "vtkThreshold.h"
> //renderização
> #include "vtkPolyDataMapper.h"
> #include "vtkActor.h"
> #include "vtkRenderer.h"
> #include "vtkRenderWindow.h"
> #include "vtkRenderWindowInteractor.h"
> #include "vtkImageSobel3D.h"
>
> #include "vtkXMLPolyDataWriter.h"
>
> // main function
>
> int main( int argc, char *argv[] )
> {
>
>        vtkStructuredPointsReader *imp1 = vtkStructuredPointsReader::New();
>        imp1 -> SetFileName( argv[1] );
>        imp1 -> Update();
>
>        vtkImageGaussianSmooth *smooth = vtkImageGaussianSmooth::New();
>        smooth->SetInput(imp1->GetOutput());
>        smooth->SetDimensionality(3);
>        smooth->SetStandardDeviations(1,1,1);
>        smooth->Update();
>
>
>        vtkSmartPointer<vtkImageMarchingCubes> mc =
>        vtkSmartPointer<vtkImageMarchingCubes>::New();
>        mc->SetInput(smooth->GetOutput());
>        mc->ComputeNormalsOn();
>        mc->ComputeScalars();
>        mc->ComputeGardientsOn();
>        mc->GenerateValues(1,atof(argv[2]),atof(argv[3]));
>        mc->Update();
>
>        vtkSmartPointer<vtkRenderer> renderer =
> vtkSmartPointer<vtkRenderer>::New();
>        renderer->SetBackground(.1, .2, .3);
>
>        vtkSmartPointer<vtkRenderWindow> renderWindow =
> vtkSmartPointer<vtkRenderWindow>::New();
>        renderWindow->AddRenderer(renderer);
>        vtkSmartPointer<vtkRenderWindowInteractor> interactor =
> vtkSmartPointer<vtkRenderWindowInteractor>::New();
>        interactor->SetRenderWindow(renderWindow);
>
>        vtkSmartPointer<vtkPolyDataMapper> mapper =
> vtkSmartPointer<vtkPolyDataMapper>::New();
>        mapper->SetInputConnection(mc->GetOutputPort()); //mc->GetOutputPort()
>
>        vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
>        actor->SetMapper(mapper);
>
>        renderer->AddActor(actor);
>
>        renderWindow->Render();
>        interactor->Start();
>
>        vtkPolyData * out = vtkPolyData::New();
>        out = mc->GetOutput();
>        out ->Update();
>
>        //Writer
>        vtkPolyDataWriter *writer =vtkPolyDataWriter::New();
>        writer ->SetInput(out);
>        writer->SetFileTypeToASCII();
>        writer ->SetFileName("output.vtk");
>        writer ->Update();
>
>        //XML Writer
>
>        vtkXMLPolyDataWriter * writer2 = vtkXMLPolyDataWriter::New();
>        writer2->SetInput(out);
>        writer2->SetDataModeToAscii();
>        writer2->SetFileName("outputXML.vtp");
>        writer2->Update();
>
>
>
> }

Unfortunately I don't know the answer to your question. However, some tips:

This is wrong:
 vtkPolyData * out = vtkPolyData::New();
       out = mc->GetOutput();
       out ->Update();

You are creating a new 'out' object, but then changing the pointer to
the output of 'mc'. You should simply do:
vtkPolyData * out = mc->GetOutput();

Also, you should always use the SetInputConnection/GetOutputPort (or
GetProducerPort) rather than SetInput/GetOutput pair. It is just the
"new" thing to do.

Change:
       vtkPolyDataWriter *writer =vtkPolyDataWriter::New();
       writer ->SetInput(out);

to
       vtkPolyDataWriter *writer =vtkPolyDataWriter::New();
       writer ->SetInputConnection(out->GetProducerPort());

GetOutputPort is for filter, GetProducerPort is for objects (like vtkPolyData).

I suggest you start a new thread with your new problem, as the current
title is not very indicative of the problem.

David