MultipleViewports

Description¶

This example creates a window with 4 viewports. Updating the camera position in one viewport will also update the position in the other viewports.

See MultipleRenderWindows for an example using multiple windows.

Other languages

See (Python), (PythonicAPI), (Java)

Question

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

Code¶

MultipleViewports.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkConeSource.h>
#include <vtkCubeSource.h>
#include <vtkCylinderSource.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>

#include <vector>

namespace {
std::vector<vtkSmartPointer<vtkPolyDataAlgorithm>> GetSources();
}

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

  vtkNew<vtkRenderWindow> renderWindow;

  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;

  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Define viewport ranges.
  double xmins[4] = {0, .5, 0, .5};
  double xmaxs[4] = {0.5, 1, 0.5, 1};
  double ymins[4] = {0, 0, .5, .5};
  double ymaxs[4] = {0.5, 0.5, 1, 1};
  // Have some fun with colors.
  std::vector<std::string> renBkg{"AliceBlue", "GhostWhite", "WhiteSmoke",
                                  "Seashell"};
  std::vector<std::string> actorColor{"Bisque", "RosyBrown", "Goldenrod",
                                      "Chocolate"};
  vtkCamera* camera = nullptr;
  auto sources = GetSources();

  for (unsigned i = 0; i < 4; i++)
  {
    vtkNew<vtkRenderer> renderer;

    renderWindow->AddRenderer(renderer);
    renderer->SetViewport(xmins[i], ymins[i], xmaxs[i], ymaxs[i]);

    // Share the camera between viewports.
    if (i == 0)
    {
      camera = renderer->GetActiveCamera();
      camera->Azimuth(30);
      camera->Elevation(30);
    }
    else
    {
      renderer->SetActiveCamera(camera);
    }

    // Create a mapper and actor.
    vtkNew<vtkPolyDataMapper> mapper;
    mapper->SetInputConnection(sources[i]->GetOutputPort());
    vtkNew<vtkActor> actor;
    actor->SetMapper(mapper);
    actor->GetProperty()->SetColor(colors->GetColor3d(actorColor[i]).GetData());

    renderer->AddActor(actor);
    renderer->SetBackground(colors->GetColor3d(renBkg[i]).GetData());

    renderer->ResetCamera();
  }
  renderWindow->Render();
  renderWindow->SetWindowName("MultipleViewPorts");
  renderWindow->SetSize(600, 600);

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

namespace {
std::vector<vtkSmartPointer<vtkPolyDataAlgorithm>> GetSources()
{
  std::vector<vtkSmartPointer<vtkPolyDataAlgorithm>> sources;
  for (unsigned i = 0; i < 4; i++)
  {
    // Create a sphere.
    vtkNew<vtkSphereSource> sphere;
    sphere->SetCenter(0.0, 0.0, 0.0);
    sphere->Update();
    sources.push_back(sphere);
    // Create a cone.
    vtkNew<vtkConeSource> cone;
    cone->SetCenter(0.0, 0.0, 0.0);
    cone->SetDirection(0, 1, 0);
    cone->Update();
    sources.push_back(cone);
    // Create a cube.
    vtkNew<vtkCubeSource> cube;
    cube->SetCenter(0.0, 0.0, 0.0);
    cube->Update();
    sources.push_back(cube);
    // Create a cylinder.
    vtkNew<vtkCylinderSource> cylinder;
    cylinder->SetCenter(0.0, 0.0, 0.0);
    cylinder->Update();
    sources.push_back(cylinder);
  }
  return sources;
}

} // namespace

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(MultipleViewports)

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

if (NOT VTK_FOUND)
  message(FATAL_ERROR "MultipleViewports: 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(MultipleViewports MACOSX_BUNDLE MultipleViewports.cxx )
  target_link_libraries(MultipleViewports PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS MultipleViewports
  MODULES ${VTK_LIBRARIES}
)

Download and Build MultipleViewports¶

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

cd MultipleViewports/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:

./MultipleViewports

WINDOWS USERS

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