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.

Other languages

See (Java)

Question

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

Code¶

TrackballCamera.cxx

#include <vtkActor.h>
#include <vtkConeSource.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

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

  // Create a sphere.
  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->SetCenter(1.0, 0.0, 0.0);
  sphereSource->Update();

  // Create a mapper and actor.
  vtkNew<vtkPolyDataMapper> sphereMapper;
  sphereMapper->SetInputConnection(sphereSource->GetOutputPort());

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

  // Create a cone.
  vtkNew<vtkConeSource> coneSource;

  // Create a mapper and actor.
  vtkNew<vtkPolyDataMapper> coneMapper;
  coneMapper->SetInputConnection(coneSource->GetOutputPort());

  vtkNew<vtkActor> coneActor;
  coneActor->SetMapper(coneMapper);
  coneActor->GetProperty()->SetColor(
      colors->GetColor3d("LightGoldenrodYellow").GetData());

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

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

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

  // Render an image (lights and cameras are created automatically)
  renderWindow->Render();

  vtkNew<vtkInteractorStyleTrackballCamera> style;

  renderWindowInteractor->SetInteractorStyle(style);

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

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(TrackballCamera)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  FiltersSources
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "TrackballCamera: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
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}
)

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.