BalloonWidget

VTKExamples/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 simple question about this example contact us at VTKExamplesProject If your question is more complex and may require extended discussion, 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 <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkRegularPolygonSource.h>

int main (int, char *[])
{
  // Sphere
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetCenter(-4.0, 0.0, 0.0);
  sphereSource->SetRadius(4.0);
  sphereSource->Update();

  vtkSmartPointer<vtkPolyDataMapper> sphereMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  sphereMapper->SetInputConnection(sphereSource->GetOutputPort());

  vtkSmartPointer<vtkActor> sphereActor =
    vtkSmartPointer<vtkActor>::New();
  sphereActor->SetMapper(sphereMapper);

  // Regular Polygon
  vtkSmartPointer<vtkRegularPolygonSource> regularPolygonSource =
    vtkSmartPointer<vtkRegularPolygonSource>::New();
  regularPolygonSource->SetCenter(4.0, 0.0, 0.0);
  regularPolygonSource->SetRadius(4.0);
  regularPolygonSource->Update();

  vtkSmartPointer<vtkPolyDataMapper> regularPolygonMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  regularPolygonMapper->SetInputConnection(regularPolygonSource->GetOutputPort());

  vtkSmartPointer<vtkActor> regularPolygonActor =
    vtkSmartPointer<vtkActor>::New();
  regularPolygonActor->SetMapper(regularPolygonMapper);

  // A renderer and render window
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);

  // An interactor
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Create the widget
  vtkSmartPointer<vtkBalloonRepresentation> balloonRep =
    vtkSmartPointer<vtkBalloonRepresentation>::New();
  balloonRep->SetBalloonLayoutToImageRight();

  vtkSmartPointer<vtkBalloonWidget> balloonWidget =
    vtkSmartPointer<vtkBalloonWidget>::New();
  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);

  // 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 
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersSources
  vtkInteractionStyle
  vtkInteractionWidgets
  vtkRenderingCore
  vtkRenderingFreeType
  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.