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BalloonWidget

vtk-examples/Cxx/Widgets/BalloonWidget


Description

This example creates a sphere and a regular polygon. The balloon text describes each object when you hover over it.

Note

This original source code for this example is here.

Other languages

See (Python), (Java)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

BalloonWidget.cxx

#include <vtkActor.h>
#include <vtkBalloonRepresentation.h>
#include <vtkBalloonWidget.h>
#include <vtkCommand.h>
#include <vtkInteractorStyleTrackball.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkNew.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkRegularPolygonSource.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkNew.h>
#include <vtkSphereSource.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkProperty.h>

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  // Sphere
  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->SetCenter(-4.0, 0.0, 0.0);
  sphereSource->SetRadius(4.0);
  sphereSource->Update();

  vtkNew<vtkPolyDataMapper> sphereMapper;
  sphereMapper->SetInputConnection(sphereSource->GetOutputPort());

  vtkNew<vtkActor> sphereActor;
  sphereActor->SetMapper(sphereMapper);
  sphereActor->GetProperty()->SetColor(
      colors->GetColor3d("MistyRose").GetData());

  // Regular Polygon
  vtkNew<vtkRegularPolygonSource> regularPolygonSource;
  regularPolygonSource->SetCenter(4.0, 0.0, 0.0);
  regularPolygonSource->SetRadius(4.0);
  regularPolygonSource->Update();

  vtkNew<vtkPolyDataMapper> regularPolygonMapper;
  regularPolygonMapper->SetInputConnection(
      regularPolygonSource->GetOutputPort());

  vtkNew<vtkActor> regularPolygonActor;
  regularPolygonActor->SetMapper(regularPolygonMapper);
  regularPolygonActor->GetProperty()->SetColor(
      colors->GetColor3d("Cornsilk").GetData());

  // A renderer and render window
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("BalloonWidget");

  // An interactor
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Create the widget
  vtkNew<vtkBalloonRepresentation> balloonRep;
  balloonRep->SetBalloonLayoutToImageRight();

  vtkNew<vtkBalloonWidget> balloonWidget;
  balloonWidget->SetInteractor(renderWindowInteractor);
  balloonWidget->SetRepresentation(balloonRep);
  balloonWidget->AddBalloon(sphereActor, "This is a sphere", NULL);
  balloonWidget->AddBalloon(regularPolygonActor, "This is a regular polygon",
                            NULL);

  // Add the actors to the scene
  renderer->AddActor(sphereActor);
  renderer->AddActor(regularPolygonActor);
  renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());

  // Render
  renderWindow->Render();
  balloonWidget->EnabledOn();

  // Begin mouse interaction
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(BalloonWidget)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersSources
  vtkInteractionStyle
  vtkInteractionWidgets
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping BalloonWidget: ${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(BalloonWidget MACOSX_BUNDLE BalloonWidget.cxx )
  target_link_libraries(BalloonWidget PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(BalloonWidget MACOSX_BUNDLE BalloonWidget.cxx )
  target_link_libraries(BalloonWidget PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS BalloonWidget
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build BalloonWidget

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

cd BalloonWidget/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:

./BalloonWidget

WINDOWS USERS

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