TrackballCamera

VTKExamples/Cxx/Interaction/TrackballCamera

Description

This example demonstrates the trackball camera mode. When the mouse is clicked and dragged from anywhere in the window, the camera is modified.

Contrast this with TrackballActor.

Code

TrackballCamera.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 <vtkInteractorStyleTrackballCamera.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 an image (lights and cameras are created automatically)
  renderWindow->SetWindowName("Trackball Camera");
  renderWindow->Render();

  vtkSmartPointer<vtkInteractorStyleTrackballCamera> style = 
    vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New(); //like paraview

  renderWindowInteractor->SetInteractorStyle( style );

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

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(TrackballCamera)

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

Download and Build TrackballCamera

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

cd TrackballCamera/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:

./TrackballCamera

WINDOWS USERS

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