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ColorDisconnectedRegions

vtk-examples/Cxx/PolyData/ColorDisconnectedRegions


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Question

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Code

ColorDisconnectedRegions.cxx

#include <vtkActor.h>
#include <vtkAppendPolyData.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPointData.h>
#include <vtkPolyDataConnectivityFilter.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 some spheres
  vtkNew<vtkSphereSource> sphereSource1;
  sphereSource1->Update();

  vtkNew<vtkSphereSource> sphereSource2;
  sphereSource2->SetCenter(5, 0, 0);
  sphereSource2->Update();

  vtkNew<vtkSphereSource> sphereSource3;
  sphereSource3->SetCenter(10, 0, 0);
  sphereSource3->Update();

  vtkNew<vtkAppendPolyData> appendFilter;
  appendFilter->AddInputConnection(sphereSource1->GetOutputPort());
  appendFilter->AddInputConnection(sphereSource2->GetOutputPort());
  appendFilter->AddInputConnection(sphereSource3->GetOutputPort());
  appendFilter->Update();

  vtkNew<vtkPolyDataConnectivityFilter> connectivityFilter;
  connectivityFilter->SetInputConnection(appendFilter->GetOutputPort());
  connectivityFilter->SetExtractionModeToAllRegions();
  connectivityFilter->ColorRegionsOn();
  connectivityFilter->Update();

  // Visualize
  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(connectivityFilter->GetOutputPort());
  mapper->SetScalarRange(connectivityFilter->GetOutput()
                             ->GetPointData()
                             ->GetArray("RegionId")
                             ->GetRange());
  mapper->Update();

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);

  vtkNew<vtkRenderer> renderer;
  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("Silver").GetData());

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetSize(640, 480);
  renderWindow->SetWindowName("ColorDisconnectedRegions");

  vtkNew<vtkRenderWindowInteractor> interactor;
  interactor->SetRenderWindow(renderWindow);

  renderWindow->Render();
  interactor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(ColorDisconnectedRegions)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersCore
  vtkFiltersSources
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping ColorDisconnectedRegions: ${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(ColorDisconnectedRegions MACOSX_BUNDLE ColorDisconnectedRegions.cxx )
  target_link_libraries(ColorDisconnectedRegions PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(ColorDisconnectedRegions MACOSX_BUNDLE ColorDisconnectedRegions.cxx )
  target_link_libraries(ColorDisconnectedRegions PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS ColorDisconnectedRegions
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build ColorDisconnectedRegions

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

cd ColorDisconnectedRegions/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:

./ColorDisconnectedRegions

WINDOWS USERS

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