VTK/Examples/Cxx/PolyData/ExternalContour
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Jump to navigationJump to searchCompute the external contour of a polydata.
At first, it creates a black and white image of a scene containing the polydata and then extracts the contour of the black shape from the image.
ExternalContour.cxx
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkPolyData.h>
#include <vtkWindowToImageFilter.h>
#include <vtkContourFilter.h>
#include <vtkTransform.h>
#include <vtkTransformPolyDataFilter.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkProperty.h>
#include <vtkCamera.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkXMLPolyDataReader.h>
int main(int argc, char *argv[])
{
vtkSmartPointer<vtkPolyData> data3d;
if ( argc == 2 )
{
vtkSmartPointer<vtkXMLPolyDataReader> reader =
vtkSmartPointer<vtkXMLPolyDataReader>::New();
reader->SetFileName (argv[1]);
reader->Update();
data3d = reader->GetOutput();
}
else
{
vtkSmartPointer<vtkSphereSource> source =
vtkSmartPointer<vtkSphereSource>::New();
source->SetCenter(0.0, 0.0, 5.0);
source->SetRadius(2.0);
source->SetPhiResolution(20.);
source->SetThetaResolution(20.);
source->Update();
data3d = source->GetOutput();
}
double bounds_data[6], center_data[3];
data3d->GetBounds(bounds_data);
data3d->GetCenter(center_data);
// Black and white scene with the data in order to print the view
vtkSmartPointer<vtkPolyDataMapper> mapper_data =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper_data->SetInput(data3d);
vtkSmartPointer<vtkActor> actor_data =
vtkSmartPointer<vtkActor>::New();
actor_data->SetMapper(mapper_data);
actor_data->GetProperty()->SetColor(0,0,0);
vtkSmartPointer<vtkRenderer> tmp_rend =
vtkSmartPointer<vtkRenderer>::New();
tmp_rend->SetBackground(1,1,1);
tmp_rend->AddActor(actor_data);
tmp_rend->ResetCamera();
tmp_rend->GetActiveCamera()->SetParallelProjection(1);
vtkSmartPointer<vtkRenderWindow> tmp_rW =
vtkSmartPointer<vtkRenderWindow>::New();
tmp_rW->SetOffScreenRendering( 1 );
tmp_rW->AddRenderer(tmp_rend);
tmp_rW->Render();
// Get a print of the window
vtkSmartPointer<vtkWindowToImageFilter> windowToImageFilter =
vtkSmartPointer<vtkWindowToImageFilter>::New();
windowToImageFilter->SetInput(tmp_rW);
windowToImageFilter->SetMagnification(2);//image quality
windowToImageFilter->Update();
// Extract the silhouette corresponding to the black limit of the image
vtkSmartPointer<vtkContourFilter> ContFilter = vtkSmartPointer<vtkContourFilter>::New();
ContFilter->SetInputConnection(windowToImageFilter->GetOutputPort());
ContFilter->SetValue(0,255);
ContFilter->Update();
// Make the contour coincide with the data.
vtkSmartPointer<vtkPolyData> contour = ContFilter->GetOutput();
double bounds_contour[6], center_contour[3];
double trans_x=0., trans_y=0., trans_z=0., ratio_x=0., ratio_y=0.;
contour->GetBounds(bounds_contour);
ratio_x = (bounds_data[1]-bounds_data[0])/(bounds_contour[1]-bounds_contour[0]);
ratio_y = (bounds_data[3]-bounds_data[2])/(bounds_contour[3]-bounds_contour[2]);
// Rescale the contour so that it shares the same bounds as the input data
vtkTransform* transform1 = vtkTransform::New();
transform1->Scale( ratio_x, ratio_y, 1.);
vtkTransformPolyDataFilter* tfilter1 = vtkTransformPolyDataFilter::New();
tfilter1->SetInput(contour);
tfilter1->SetTransform(transform1);
tfilter1->Update();
contour = tfilter1->GetOutput();
// Translate the contour so that it shares the same center as the input data
contour->GetCenter(center_contour);
trans_x = center_data[0]-center_contour[0];
trans_y = center_data[1]-center_contour[1];
trans_z = center_data[2]-center_contour[2];
vtkTransform* transform2 = vtkTransform::New();
transform2->Translate( trans_x, trans_y, trans_z);
vtkTransformPolyDataFilter* tfilter2 = vtkTransformPolyDataFilter::New();
tfilter2->SetInput(contour);
tfilter2->SetTransform(transform2);
tfilter2->Update();
contour = tfilter2->GetOutput();
// Render the result : Input data + resulting silhouette
//Updating the color of the data
actor_data->GetProperty()->SetColor(0.9,0.9,0.8);
// Create a mapper and actor of the silhouette
vtkSmartPointer<vtkPolyDataMapper> mapper_contour =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper_contour->SetInput(contour);
vtkSmartPointer<vtkActor> actor_contour =
vtkSmartPointer<vtkActor>::New();
actor_contour->SetMapper(mapper_contour);
actor_contour->GetProperty()->SetLineWidth(2.);
// 2 renderers and a render window
vtkSmartPointer<vtkRenderer> renderer1 =
vtkSmartPointer<vtkRenderer>::New();
renderer1->AddActor(actor_data);
vtkSmartPointer<vtkRenderer> renderer2 =
vtkSmartPointer<vtkRenderer>::New();
renderer2->AddActor(actor_contour);
vtkSmartPointer<vtkRenderWindow> renderwindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderwindow->SetSize(400,400);
renderwindow->AddRenderer(renderer1);
renderer1->SetViewport(0., 0., 0.5, 1.);
renderwindow->AddRenderer(renderer2);
renderer2->SetViewport(0.5, 0., 1., 1.);
vtkSmartPointer<vtkInteractorStyleTrackballCamera> style =
vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
vtkSmartPointer<vtkRenderWindowInteractor> iren =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
iren->SetRenderWindow( renderwindow);
iren->SetInteractorStyle(style);
renderwindow->Render();
iren->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.6)
PROJECT(ExternalContour)
FIND_PACKAGE(VTK REQUIRED)
INCLUDE(${VTK_USE_FILE})
ADD_EXECUTABLE(ExternalContour ExternalContour.cxx)
TARGET_LINK_LIBRARIES(ExternalContour vtkHybrid)