TrackballActor

VTKEx/Cxx/Interaction/TrackballActor

Description¶

This example shows how to visualize data in "trackball" mode. That is, click and drag actors is the way to interact.

Contrast this with TrackballCamera.

Code¶

TrackballActor.cxx

#include <vtkSmartPointer.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyData.h>
#include <vtkSphereSource.h>
#include <vtkConeSource.h>
#include <vtkInteractorStyleTrackballActor.h>

int main (int, char *[])
{
  // Create a sphere
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetCenter(1.0, 0.0, 0.0);
  sphereSource->Update();

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

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

  // Create a cone
  vtkSmartPointer<vtkConeSource> coneSource =
    vtkSmartPointer<vtkConeSource>::New();

  // Create a mapper and actor
  vtkSmartPointer<vtkPolyDataMapper> coneMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  coneMapper->SetInputConnection(coneSource->GetOutputPort());

  vtkSmartPointer<vtkActor> coneActor =
    vtkSmartPointer<vtkActor>::New();
  coneActor->SetMapper(coneMapper);

  // 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);

  // Add the actors to the scene
  renderer->AddActor(sphereActor);
  renderer->AddActor(coneActor);
  renderer->SetBackground(.1, .2, .3); // Background color dark blue

  // Render
  renderWindow->SetWindowName("Trackball Actor");
  renderWindow->Render();

  vtkSmartPointer<vtkInteractorStyleTrackballActor> style = 
      vtkSmartPointer<vtkInteractorStyleTrackballActor>::New();

  renderWindowInteractor->SetInteractorStyle( style );

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

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(TrackballActor)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersSources
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping TrackballActor: ${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(TrackballActor MACOSX_BUNDLE TrackballActor.cxx )
  target_link_libraries(TrackballActor PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(TrackballActor MACOSX_BUNDLE TrackballActor.cxx )
  target_link_libraries(TrackballActor PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS TrackballActor
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build TrackballActor¶

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

cd TrackballActor/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:

./TrackballActor