ExtractCellsUsingPoints
vtk-examples/Cxx/PolyData/ExtractCellsUsingPoints
Question
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Code¶
ExtractCellsUsingPoints.cxx
#include <vtkCamera.h>
#include <vtkDataSetMapper.h>
#include <vtkExtractSelection.h>
#include <vtkIdTypeArray.h>
#include <vtkInformation.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSelection.h>
#include <vtkSelectionNode.h>
#include <vtkSphereSource.h>
#include <vtkUnstructuredGrid.h>
int main(int, char*[])
{
vtkNew<vtkNamedColors> colors;
vtkNew<vtkSphereSource> sphereSource;
sphereSource->Update();
std::cout << "There are " << sphereSource->GetOutput()->GetNumberOfPoints()
<< " input points." << std::endl;
std::cout << "There are " << sphereSource->GetOutput()->GetNumberOfCells()
<< " input cells." << std::endl;
vtkNew<vtkIdTypeArray> ids;
ids->SetNumberOfComponents(1);
// Set values
for (vtkIdType i = 0; i < sphereSource->GetOutput()->GetNumberOfPoints() - 15;
i++)
{
ids->InsertNextValue(i);
}
vtkNew<vtkSelectionNode> selectionNode;
selectionNode->SetFieldType(vtkSelectionNode::POINT);
selectionNode->SetContentType(vtkSelectionNode::INDICES);
selectionNode->SetSelectionList(ids);
selectionNode->GetProperties()->Set(vtkSelectionNode::CONTAINING_CELLS(), 1);
vtkNew<vtkSelection> selection;
selection->AddNode(selectionNode);
vtkNew<vtkExtractSelection> extractSelection;
extractSelection->SetInputConnection(0, sphereSource->GetOutputPort());
extractSelection->SetInputData(1, selection);
extractSelection->Update();
// In selection
vtkNew<vtkUnstructuredGrid> selected;
selected->ShallowCopy(extractSelection->GetOutput());
std::cout << "There are " << selected->GetNumberOfPoints()
<< " points in the selection." << std::endl;
std::cout << "There are " << selected->GetNumberOfCells()
<< " cells in the selection." << std::endl;
// Get points that are NOT in the selection.
selectionNode->GetProperties()->Set(vtkSelectionNode::INVERSE(),
1); // invert the selection
extractSelection->Update();
vtkNew<vtkUnstructuredGrid> notSelected;
notSelected->ShallowCopy(extractSelection->GetOutput());
std::cout << "There are " << notSelected->GetNumberOfPoints()
<< " points NOT in the selection." << std::endl;
std::cout << "There are " << notSelected->GetNumberOfCells()
<< " cells NOT in the selection." << std::endl;
vtkNew<vtkProperty> backfaces;
backfaces->SetColor(colors->GetColor3d("Gold").GetData());
vtkNew<vtkDataSetMapper> inputMapper;
inputMapper->SetInputConnection(sphereSource->GetOutputPort());
vtkNew<vtkActor> inputActor;
inputActor->SetMapper(inputMapper);
inputActor->GetProperty()->SetColor(
colors->GetColor3d("MistyRose").GetData());
vtkNew<vtkDataSetMapper> selectedMapper;
selectedMapper->SetInputData(selected);
vtkNew<vtkActor> selectedActor;
selectedActor->SetMapper(selectedMapper);
selectedActor->GetProperty()->SetColor(
colors->GetColor3d("MistyRose").GetData());
vtkNew<vtkProperty> backProperty;
selectedActor->SetBackfaceProperty(backProperty);
selectedActor->SetBackfaceProperty(backfaces);
vtkNew<vtkDataSetMapper> notSelectedMapper;
notSelectedMapper->SetInputData(notSelected);
vtkNew<vtkActor> notSelectedActor;
notSelectedActor->SetMapper(notSelectedMapper);
notSelectedActor->GetProperty()->SetColor(
colors->GetColor3d("MistyRose").GetData());
notSelectedActor->SetBackfaceProperty(backfaces);
// There will be one render window.
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->SetSize(900, 300);
renderWindow->SetWindowName("ExtractCellsUsingPoints");
// And one interactor.
vtkNew<vtkRenderWindowInteractor> interactor;
interactor->SetRenderWindow(renderWindow);
// Define viewport ranges.
// (xmin, ymin, xmax, ymax)
double leftViewport[4] = {0.0, 0.0, 0.33, 1.0};
double centerViewport[4] = {0.33, 0.0, .66, 1.0};
double rightViewport[4] = {0.66, 0.0, 1.0, 1.0};
// Create a camera for all renderers.
vtkNew<vtkCamera> camera;
// Setup the renderers.
vtkNew<vtkRenderer> leftRenderer;
renderWindow->AddRenderer(leftRenderer);
leftRenderer->SetViewport(leftViewport);
leftRenderer->SetBackground(colors->GetColor3d("BurlyWood").GetData());
leftRenderer->SetActiveCamera(camera);
vtkNew<vtkRenderer> centerRenderer;
renderWindow->AddRenderer(centerRenderer);
centerRenderer->SetViewport(centerViewport);
centerRenderer->SetBackground(colors->GetColor3d("orchid_dark").GetData());
centerRenderer->SetActiveCamera(camera);
vtkNew<vtkRenderer> rightRenderer;
renderWindow->AddRenderer(rightRenderer);
rightRenderer->SetViewport(rightViewport);
rightRenderer->SetBackground(colors->GetColor3d("CornflowerBlue").GetData());
rightRenderer->SetActiveCamera(camera);
leftRenderer->AddActor(inputActor);
centerRenderer->AddActor(selectedActor);
rightRenderer->AddActor(notSelectedActor);
leftRenderer->ResetCamera();
renderWindow->Render();
interactor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(ExtractCellsUsingPoints)
find_package(VTK COMPONENTS
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "ExtractCellsUsingPoints: 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(ExtractCellsUsingPoints MACOSX_BUNDLE ExtractCellsUsingPoints.cxx )
target_link_libraries(ExtractCellsUsingPoints PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS ExtractCellsUsingPoints
MODULES ${VTK_LIBRARIES}
)
Download and Build ExtractCellsUsingPoints¶
Click here to download ExtractCellsUsingPoints and its CMakeLists.txt file. Once the tarball ExtractCellsUsingPoints.tar has been downloaded and extracted,
cd ExtractCellsUsingPoints/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:
./ExtractCellsUsingPoints
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.