【vtk實例】平面切割

用到的主要類爲  vtkImplicitPlaneWidget2

參考實例：http://www.vtk.org/Wiki/VTK/Examples/Cxx/Widgets/ImplicitPlaneWidget2

界面效果：

#include <vtkSmartPointer.h>
 
#include <vtkXMLPolyDataReader.h>
#include <vtkSphereSource.h>
#include <vtkClipPolyData.h>
#include <vtkPlane.h>
 
#include <vtkCommand.h>
#include <vtkImplicitPlaneWidget2.h>
#include <vtkImplicitPlaneRepresentation.h>
 
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
 
// Callback for the interaction
// This does the actual work: updates the vtkPlane implicit function.
// This in turn causes the pipeline to update and clip the object.
class vtkIPWCallback : public vtkCommand
{
public:
  static vtkIPWCallback *New() 
    { return new vtkIPWCallback; }
  virtual void Execute(vtkObject *caller, unsigned long, void*)
    {
    vtkImplicitPlaneWidget2 *planeWidget = 
      reinterpret_cast<vtkImplicitPlaneWidget2*>(caller);
    vtkImplicitPlaneRepresentation *rep = 
      reinterpret_cast<vtkImplicitPlaneRepresentation*>(planeWidget->GetRepresentation());
    rep->GetPlane(this->Plane);
    }
  vtkIPWCallback():Plane(0),Actor(0) {}
  vtkPlane *Plane;
  vtkActor *Actor;
 
};
 
int main(int argc, char *argv[])
{
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetRadius(10.0);
 
  vtkSmartPointer<vtkXMLPolyDataReader> reader =
    vtkSmartPointer<vtkXMLPolyDataReader>::New();
 
  // Setup a visualization pipeline
  vtkSmartPointer<vtkPlane> plane =
    vtkSmartPointer<vtkPlane>::New();
  vtkSmartPointer<vtkClipPolyData> clipper =
    vtkSmartPointer<vtkClipPolyData>::New();
  clipper->SetClipFunction(plane);
  clipper->InsideOutOn();
  if (argc < 2)
    {
    clipper->SetInputConnection(sphereSource->GetOutputPort());
    }
  else
    {
    reader->SetFileName(argv[1]);
    clipper->SetInputConnection(reader->GetOutputPort());
    }
 
  // Create a mapper and actor
  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputConnection(clipper->GetOutputPort());
  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
 
  vtkSmartPointer<vtkProperty> backFaces =
    vtkSmartPointer<vtkProperty>::New();
  backFaces->SetDiffuseColor(.8, .8, .4);
 
  actor->SetBackfaceProperty(backFaces);
 
  // A renderer and render window
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  renderer->AddActor(actor);
 
  // An interactor
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
 
  renderWindow->Render();
 
  // The callback will do the work
  vtkSmartPointer<vtkIPWCallback> myCallback = 
    vtkSmartPointer<vtkIPWCallback>::New();
  myCallback->Plane = plane;
  myCallback->Actor = actor;
 
  vtkSmartPointer<vtkImplicitPlaneRepresentation> rep = 
    vtkSmartPointer<vtkImplicitPlaneRepresentation>::New();
  rep->SetPlaceFactor(1.25); // This must be set prior to placing the widget
  rep->PlaceWidget(actor->GetBounds());
  rep->SetNormal(plane->GetNormal());
  rep->SetOrigin(0,0,50); //this doesn't seem to work?
 
  vtkSmartPointer<vtkImplicitPlaneWidget2> planeWidget =
    vtkSmartPointer<vtkImplicitPlaneWidget2>::New();
  planeWidget->SetInteractor(renderWindowInteractor);
  planeWidget->SetRepresentation(rep);
  planeWidget->AddObserver(vtkCommand::InteractionEvent,myCallback);
 
  // Render
 
  renderWindowInteractor->Initialize();
  renderWindow->Render();
  planeWidget->On();
 
  // Begin mouse interaction
  renderWindowInteractor->Start();
 
  return EXIT_SUCCESS;
}