SeedWidgetWithCustomCallback

VTKEx/Cxx/Widgets/SeedWidgetWithCustomCallback

Description

This example demonstrates how to place seed points in the scene. The seed points can be used for operations like connectivity, segmentation, and region growing.

Question

If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum

Code

SeedWidgetWithCustomCallback.cxx

#include <vtkActor.h>
#include <vtkCommand.h>
#include <vtkPointHandleRepresentation2D.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty2D.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSeedRepresentation.h>
#include <vtkSeedWidget.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>

class vtkSeedCallback : public vtkCommand
{
  public:
    static vtkSeedCallback *New()
    {
      return new vtkSeedCallback;
    }

    vtkSeedCallback() {}

    virtual void Execute(vtkObject*, unsigned long event, void *calldata)
    {
      if(event == vtkCommand::PlacePointEvent)
      {
        std::cout << "Point placed, total of: "
            << this->SeedRepresentation->GetNumberOfSeeds() << std::endl;
      }
      if(event == vtkCommand::InteractionEvent)
      {
        if(calldata)
        {
          std::cout << "Interacting with seed : "
              << *(static_cast< int * >(calldata)) << std::endl;
        }
      }


      std::cout << "List of seeds (Display coordinates):" << std::endl;
      for(vtkIdType i = 0; i < this->SeedRepresentation->GetNumberOfSeeds(); i++)
      {
        double pos[3];
        this->SeedRepresentation->GetSeedDisplayPosition(i, pos);
        std::cout << "(" << pos[0] << " " << pos[1] << " " << pos[2] << ")" << std::endl;
      }

    }

    void SetRepresentation(vtkSmartPointer<vtkSeedRepresentation> rep) {this->SeedRepresentation = rep;}
  private:
    vtkSmartPointer<vtkSeedRepresentation> SeedRepresentation;
};

int main(int, char *[])
{
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->Update();

  // Create a mapper and actor
  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputConnection(sphereSource->GetOutputPort());
  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);

  // 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);

  // Create the representation
  vtkSmartPointer<vtkPointHandleRepresentation2D> handle =
    vtkSmartPointer<vtkPointHandleRepresentation2D>::New();
  handle->GetProperty()->SetColor(1,0,0);
  vtkSmartPointer<vtkSeedRepresentation> rep =
    vtkSmartPointer<vtkSeedRepresentation>::New();
  rep->SetHandleRepresentation(handle);

  // Seed widget
  vtkSmartPointer<vtkSeedWidget> seedWidget =
    vtkSmartPointer<vtkSeedWidget>::New();
  seedWidget->SetInteractor(renderWindowInteractor);
  seedWidget->SetRepresentation(rep);

  vtkSmartPointer<vtkSeedCallback> seedCallback =
    vtkSmartPointer<vtkSeedCallback>::New();
  seedCallback->SetRepresentation(rep);
  seedWidget->AddObserver(vtkCommand::PlacePointEvent,seedCallback);
  seedWidget->AddObserver(vtkCommand::InteractionEvent,seedCallback);

  renderWindow->Render();

  renderWindowInteractor->Initialize();
  renderWindow->Render();
  seedWidget->On();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(SeedWidgetWithCustomCallback)

find_package(VTK COMPONENTS 
  vtkvtkCommonCore
  vtkvtkFiltersSources
  vtkvtkInteractionStyle
  vtkvtkInteractionWidgets
  vtkvtkRenderingContextOpenGL2
  vtkvtkRenderingCore
  vtkvtkRenderingFreeType
  vtkvtkRenderingGL2PSOpenGL2
  vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping SeedWidgetWithCustomCallback: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(SeedWidgetWithCustomCallback MACOSX_BUNDLE SeedWidgetWithCustomCallback.cxx )
  target_link_libraries(SeedWidgetWithCustomCallback PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(SeedWidgetWithCustomCallback MACOSX_BUNDLE SeedWidgetWithCustomCallback.cxx )
  target_link_libraries(SeedWidgetWithCustomCallback PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS SeedWidgetWithCustomCallback
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build SeedWidgetWithCustomCallback

Click here to download SeedWidgetWithCustomCallback and its CMakeLists.txt file. Once the tarball SeedWidgetWithCustomCallback.tar has been downloaded and extracted,

cd SeedWidgetWithCustomCallback/build

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./SeedWidgetWithCustomCallback

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.