private void vtkPolyDataConnectivityFilter_LargestRegion()
{
// Small sphere
vtkSphereSource sphereSource1 = vtkSphereSource.New();
sphereSource1.Update();
// Large sphere
vtkSphereSource sphereSource2 = vtkSphereSource.New();
sphereSource2.SetRadius(10);
sphereSource2.SetCenter(25, 0, 0);
sphereSource2.SetThetaResolution(10);
sphereSource2.SetPhiResolution(10);
sphereSource2.Update();
vtkAppendPolyData appendFilter = vtkAppendPolyData.New();
appendFilter.AddInputConnection(sphereSource1.GetOutputPort());
appendFilter.AddInputConnection(sphereSource2.GetOutputPort());
appendFilter.Update();
vtkPolyDataConnectivityFilter connectivityFilter = vtkPolyDataConnectivityFilter.New();
connectivityFilter.SetInputConnection(appendFilter.GetOutputPort());
connectivityFilter.SetExtractionModeToLargestRegion();
connectivityFilter.Update();
// Create a mapper and actor for original data
vtkPolyDataMapper originalMapper = vtkPolyDataMapper.New();
originalMapper.SetInputConnection(appendFilter.GetOutputPort());
originalMapper.Update();
vtkActor originalActor = vtkActor.New();
originalActor.SetMapper(originalMapper);
// Create a mapper and actor for extracted data
vtkPolyDataMapper extractedMapper = vtkPolyDataMapper.New();
extractedMapper.SetInputConnection(connectivityFilter.GetOutputPort());
extractedMapper.Update();
vtkActor extractedActor = vtkActor.New();
extractedActor.GetProperty().SetColor(1, 0, 0);
extractedActor.SetMapper(extractedMapper);
// get a reference to the renderwindow of our renderWindowControl1
vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
// renderer
vtkRenderer renderer = renderWindow.GetRenderers().GetFirstRenderer();
// set background color
renderer.SetBackground(0.2, 0.3, 0.4);
// add our actor to the renderer
renderer.AddActor(originalActor);
renderer.AddActor(extractedActor);
}
private void ExtractLargestIsoSurface(string filePath, double threshold, bool extractLargest)
{
// Load data
vtkStructuredPointsReader reader = vtkStructuredPointsReader.New();
reader.SetFileName(filePath);
// Create a 3D model using marching cubes
vtkMarchingCubes mc = vtkMarchingCubes.New();
mc.SetInputConnection(reader.GetOutputPort());
mc.ComputeNormalsOn();
mc.ComputeGradientsOn();
mc.SetValue(0, threshold); // second value acts as threshold
// To remain largest region
vtkPolyDataConnectivityFilter confilter = vtkPolyDataConnectivityFilter.New();
confilter.SetInputConnection(mc.GetOutputPort());
confilter.SetExtractionModeToLargestRegion();
// Create a mapper
vtkPolyDataMapper mapper = vtkPolyDataMapper.New();
if (extractLargest)
{
mapper.SetInputConnection(confilter.GetOutputPort());
}
else
{
mapper.SetInputConnection(mc.GetOutputPort());
}
mapper.ScalarVisibilityOff(); // utilize actor's property I set
// Visualize
vtkActor actor = vtkActor.New();
actor.GetProperty().SetColor(1, 1, 1);
actor.SetMapper(mapper);
// get a reference to the renderwindow of our renderWindowControl1
vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
// renderer
vtkRenderer renderer = renderWindow.GetRenderers().GetFirstRenderer();
// add our actor to the renderer
renderer.AddActor(actor);
}