GenericClip
vtk-examples/Cxx/Filtering/GenericClip
Description¶
Warning
This example requires vtk 6.0 or greater.
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
GenericClip.cxx
#include <vtkActor.h>
#include <vtkBridgeDataSet.h> // Must build VTK with BUILD_TESTING=ON
#include <vtkCellData.h>
#include <vtkContourFilter.h>
#include <vtkDataSetMapper.h>
#include <vtkGenericClip.h>
#include <vtkIdFilter.h>
#include <vtkIdTypeArray.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPlane.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSampleFunction.h>
#include <vtkSphereSource.h>
#include <vtkUnstructuredGrid.h>
int main(int, char*[])
{
vtkNew<vtkNamedColors> namedColors;
// If we try to use a PointSource with vtkBridgeDataSet, an error is produced:
// vtkBridgeCell.cxx:141: virtual int vtkBridgeCell::GetType(): Assertion
// `"check: impossible case" && 0' failed.
// There does not seem to be a case to handle VTK_VERTEX (which is what is
// produced by PointSource) in vtkBridgeDataSet.
// vtkNew<vtkPointSource> pointSource;
// pointSource->SetNumberOfPoints(100);
// pointSource->SetRadius(1.0);
// pointSource->Update();
vtkNew<vtkSphereSource> sphereSource;
sphereSource->SetRadius(5);
sphereSource->SetThetaResolution(10);
sphereSource->SetPhiResolution(10);
sphereSource->Update();
// Add ids to the points and cells of the sphere
vtkNew<vtkIdFilter> idFilter;
idFilter->SetInputConnection(sphereSource->GetOutputPort());
idFilter->Update();
// Create a plane to clip with
vtkNew<vtkPlane> plane;
plane->SetOrigin(0, 0, 0);
plane->SetNormal(1, 1, 1);
// Convert the DataSet to a GenericDataSet
vtkNew<vtkBridgeDataSet> bridgeDataSet;
bridgeDataSet->SetDataSet(idFilter->GetOutput());
vtkNew<vtkGenericClip> clipper;
clipper->SetClipFunction(plane);
clipper->SetInputData(bridgeDataSet);
clipper->Update();
// Get the clipped cell ids
vtkUnstructuredGrid* clipped = clipper->GetOutput();
vtkIdTypeArray* originalIds = dynamic_cast<vtkIdTypeArray*>(
clipped->GetCellData()->GetArray("vtkIdFilter_Ids"));
for (vtkIdType i = 0; i < originalIds->GetNumberOfTuples(); ++i)
{
std::cout << "new id " << i << ", original id " << originalIds->GetValue(i)
<< std::endl;
}
// Create a mapper and actor for clipped points
vtkNew<vtkDataSetMapper> mapper;
mapper->SetInputConnection(clipper->GetOutputPort());
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
// Create a mapper and actor for clipping function
vtkNew<vtkSampleFunction> sample;
sample->SetSampleDimensions(20, 20, 20);
sample->SetImplicitFunction(plane);
double value = 10.0;
double xmin = -value, xmax = value, ymin = -value, ymax = value,
zmin = -value, zmax = value;
sample->SetModelBounds(xmin, xmax, ymin, ymax, zmin, zmax);
// Create the 0 isosurface
vtkNew<vtkContourFilter> contours;
contours->SetInputConnection(sample->GetOutputPort());
contours->GenerateValues(1, 1, 1);
// Map the contours to graphical primitives
vtkNew<vtkPolyDataMapper> contourMapper;
contourMapper->SetInputConnection(contours->GetOutputPort());
contourMapper->SetScalarRange(0.0, 1.2);
// Create an actor for the sphere
vtkNew<vtkActor> sphereActor;
sphereActor->SetMapper(contourMapper);
// Create a renderer, render window, and interactor
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->AddRenderer(renderer);
vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
renderWindowInteractor->SetRenderWindow(renderWindow);
// Add the actor to the scene
renderer->AddActor(actor);
renderer->AddActor(sphereActor);
renderer->SetBackground(namedColors->GetColor3d("Burlywood").GetData());
renderer->UseHiddenLineRemovalOn();
// Render and interact
renderWindow->SetWindowName("GenericClip");
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(GenericClip)
find_package(VTK COMPONENTS
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "GenericClip: 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(GenericClip MACOSX_BUNDLE GenericClip.cxx )
target_link_libraries(GenericClip PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS GenericClip
MODULES ${VTK_LIBRARIES}
)
Download and Build GenericClip¶
Click here to download GenericClip and its CMakeLists.txt file. Once the tarball GenericClip.tar has been downloaded and extracted,
cd GenericClip/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:
./GenericClip
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.