[vtkusers] How to visualize polydata after KmeansClustering?

[kenichiro yoshimi]

Hi,

Could you try to modify the lines of your code as below?

  vtkSmartPointer<vtkPolyData> polydata =
    vtkSmartPointer<vtkPolyData>::New();
==>
  vtkSmartPointer<vtkPolyData> polydata = point;

Regards
2018年8月26日(日) 1:59 Polly Pui <polly_sukting at hotmail.com>:
>
> Hi,
>
> I would like to show my polydata with points and mark with colours after the KmeansClustering process.
>
> However, I could only get the values of the points without the visualization of the data.
>
> Can anyone please advice?
>
> Thank you so much.
>
>
> Polly
>
> --------------------------------------------------------------------------------------
>
> My code is as below:
>
> int main(int argc, char* argv[])
> {
> // Get the points into the format needed for KMeans
> vtkSmartPointer<vtkPolyData> point =
> vtkSmartPointer<vtkPolyData>::New();
>
> vtkSmartPointer<vtkPolyDataReader> reader =
> vtkSmartPointer<vtkPolyDataReader>::New();
> reader->SetFileName(argv[1]);
> reader->Update();
>
> point = reader->GetOutput();
>
> vtkSmartPointer<vtkTable> inputData =
> vtkSmartPointer<vtkTable>::New();
>
> for (int c = 0; c < 3; ++c)
> {
> std::stringstream colName;
> colName << "coord " << c;
> vtkSmartPointer<vtkDoubleArray> doubleArray =
> vtkSmartPointer<vtkDoubleArray>::New();
> doubleArray->SetNumberOfComponents(1);
> doubleArray->SetName(colName.str().c_str());
> doubleArray->SetNumberOfTuples(point->GetNumberOfPoints());
>
> for (int r = 0; r < point->GetNumberOfPoints(); ++r)
> {
> double p[3];
> point->GetPoint(r, p);
> doubleArray->SetValue(r, p[c]);
> }
> inputData->AddColumn(doubleArray);
> }
>
> vtkSmartPointer<vtkKMeansStatistics> kMeansStatistics =
> vtkSmartPointer<vtkKMeansStatistics>::New();
>
> #if VTK_MAJOR_VERSION <= 5
> kMeansStatistics->SetInput(vtkStatisticsAlgorithm::INPUT_DATA, inputData);
> #else
> kMeansStatistics->SetInputData(vtkStatisticsAlgorithm::INPUT_DATA, inputData);
> #endif
> kMeansStatistics->SetColumnStatus(inputData->GetColumnName(0), 1);
> kMeansStatistics->SetColumnStatus(inputData->GetColumnName(1), 1);
> kMeansStatistics->SetColumnStatus(inputData->GetColumnName(2), 1);
> kMeansStatistics->RequestSelectedColumns();
> kMeansStatistics->SetAssessOption(true);
> kMeansStatistics->SetDefaultNumberOfClusters(5);
> //kMeansStatistics->SetMaxNumIterations(1);
> kMeansStatistics->Update();
> //double mean0[3];
> //kMeansStatistics->GetMean(0, mean0);
> // Display the results
> kMeansStatistics->GetOutput()->Dump();
> //Group the points according to ID number
> vtkSmartPointer<vtkIntArray> clusterArray =
> vtkSmartPointer<vtkIntArray>::New();
> clusterArray->SetNumberOfComponents(1);
> clusterArray->SetName("ClusterId");
>
> for (int r = 0; r < kMeansStatistics->GetOutput()->GetNumberOfRows(); r++)
> {
> vtkVariant v = kMeansStatistics->GetOutput()->GetValue(r, kMeansStatistics->GetOutput()->GetNumberOfColumns() - 1);
> //std::cout << "Point " << r << " is in cluster " << v.ToInt() << std::endl;
> clusterArray->InsertNextValue(v.ToInt());
> }
>
> // Create a lookup table to map cell data to colors
> vtkSmartPointer<vtkLookupTable> lut =
> vtkSmartPointer<vtkLookupTable>::New();
> int tableSize = (kMeansStatistics + 1, 10);
> lut->SetNumberOfTableValues(tableSize);
> lut->Build();
>
> // Fill in a few known colors, the rest will be generated if needed
> //ColorCells tutorial https://lorensen.github.io/VTKExamples/site/Cxx/PolyData/ColorCells/
> vtkSmartPointer<vtkNamedColors> colors =
> vtkSmartPointer<vtkNamedColors>::New();
> lut->SetTableValue(0, colors->GetColor4d("Black").GetData());
> lut->SetTableValue(1, colors->GetColor4d("Banana").GetData());
> lut->SetTableValue(2, colors->GetColor4d("Tomato").GetData());
> lut->SetTableValue(3, colors->GetColor4d("Peacock").GetData());
> lut->SetTableValue(4, colors->GetColor4d("Lavender").GetData());
>
> // Output the cluster centers
>
> vtkMultiBlockDataSet* outputMetaDS = vtkMultiBlockDataSet::SafeDownCast(kMeansStatistics->GetOutputDataObject(vtkStatisticsAlgorithm::OUTPUT_MODEL));
> vtkSmartPointer<vtkTable> outputMeta = vtkTable::SafeDownCast(outputMetaDS->GetBlock(0));
> //vtkSmartPointer<vtkTable> outputMeta = vtkTable::SafeDownCast( outputMetaDS->GetBlock( 1 ) );
> vtkDoubleArray* coord0 = vtkDoubleArray::SafeDownCast(outputMeta->GetColumnByName("coord 0"));
> vtkDoubleArray* coord1 = vtkDoubleArray::SafeDownCast(outputMeta->GetColumnByName("coord 1"));
> vtkDoubleArray* coord2 = vtkDoubleArray::SafeDownCast(outputMeta->GetColumnByName("coord 2"));
>
> for (unsigned int i = 0; i < coord0->GetNumberOfTuples(); ++i)
> {
> std::cout << coord0->GetValue(i) << " " << coord1->GetValue(i) << " " << coord2->GetValue(i) << std::endl;
> }
>
> vtkSmartPointer<vtkPolyData> polydata =
> vtkSmartPointer<vtkPolyData>::New();
> //polydata->SetPoints(point);
> polydata->GetPointData()->AddArray(clusterArray);
> polydata->GetPointData()->SetScalars(clusterArray);
>
> // Display
> vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
> vtkSmartPointer<vtkVertexGlyphFilter>::New();
> #if VTK_MAJOR_VERSION <= 5
> glyphFilter->SetInputConnection(polydata->GetProducerPort());
> #else
> glyphFilter->SetInputData(polydata);
> #endif
> glyphFilter->Update();
>
> // Create a mapper and actor
> vtkSmartPointer<vtkPolyDataMapper> mapper =
> vtkSmartPointer<vtkPolyDataMapper>::New();
> mapper->SetInputConnection(glyphFilter->GetOutputPort());
> mapper->SetScalarRange(0, tableSize - 1);
> mapper->SetLookupTable(lut);
>
> vtkSmartPointer<vtkActor> actor =
> vtkSmartPointer<vtkActor>::New();
> actor->SetMapper(mapper);
> actor->GetProperty()->SetPointSize(5);
>
> // Create a renderer, render window, and interactor
> vtkSmartPointer<vtkRenderer> renderer =
> vtkSmartPointer<vtkRenderer>::New();
> vtkSmartPointer<vtkRenderWindow> renderWindow =
> vtkSmartPointer<vtkRenderWindow>::New();
> renderWindow->AddRenderer(renderer);
> renderWindow->SetSize(800, 800);
>
> vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
> vtkSmartPointer<vtkRenderWindowInteractor>::New();
> renderWindowInteractor->SetRenderWindow(renderWindow);
>
> // Add the actor to the scene
> renderer->AddActor(actor);
> renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());
>
> vtkSmartPointer<vtkInteractorStyleTrackballCamera> style =
> vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
> renderWindowInteractor->SetInteractorStyle(style);
>
> // Render and interact
> renderWindow->Render();
>
> vtkWindowToImageFilter *windowToImageFilter = vtkWindowToImageFilter::New();
> windowToImageFilter->SetInput(renderWindow);
> windowToImageFilter->Update();
>
> vtkJPEGWriter *writer = vtkJPEGWriter::New();
> writer->SetInputConnection(windowToImageFilter->GetOutputPort());
> writer->SetFileName("10nosepoints.jpg");
> writer->Write();
>
> renderWindowInteractor->Start();
>
> return EXIT_SUCCESS;
> }
>
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