SplitPolyData
VTKExamples/Cxx/Meshes/SplitPolyData
Description
The vtkOBBDicer filter breaks up an input mesh into a number of pieces. The resulting mesh contains scalar point data that can be used to extract the individual pieces with a filter like vtkThresholdFilter. This example stores each piece into a .vtp file.
Code
SplitPolyData.cxx
#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkOBBDicer.h>
#include <vtkSphereSource.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkThreshold.h>
#include <vtkGeometryFilter.h>
#include <vtksys/SystemTools.hxx>
#include <sstream>
int main(int argc, char *argv[])
{
std::string filename;
std::string extension;
vtkSmartPointer<vtkPolyData> inputPolyData;
if(argc > 1)
{
filename = vtksys::SystemTools::GetFilenameWithoutExtension(std::string(argv[1]));
extension = vtksys::SystemTools::GetFilenameExtension(std::string(argv[1]));
vtkSmartPointer<vtkXMLPolyDataReader> reader =
vtkSmartPointer<vtkXMLPolyDataReader>::New();
reader->SetFileName(argv[1]);
reader->Update();
inputPolyData = reader->GetOutput();
}
else
{
filename = "sphere";
extension = ".vtp";
vtkSmartPointer<vtkSphereSource> sphereSource =
vtkSmartPointer<vtkSphereSource>::New();
sphereSource->SetThetaResolution(30);
sphereSource->SetPhiResolution(15);
sphereSource->Update();
inputPolyData = sphereSource->GetOutput();
}
// Create pipeline
vtkSmartPointer<vtkOBBDicer> dicer =
vtkSmartPointer<vtkOBBDicer>::New();
#if VTK_MAJOR_VERSION <= 5
dicer->SetInput(inputPolyData);
#else
dicer->SetInputData(inputPolyData);
#endif
dicer->SetNumberOfPieces(4);
dicer->SetDiceModeToSpecifiedNumberOfPieces();
dicer->Update();
vtkSmartPointer<vtkThreshold> selector =
vtkSmartPointer<vtkThreshold>::New();
selector->SetInputArrayToProcess(0, 0, 0, 0, "vtkOBBDicer_GroupIds");
selector->SetInputConnection(dicer->GetOutputPort());
selector->AllScalarsOff();
vtkSmartPointer<vtkGeometryFilter> geometry =
vtkSmartPointer<vtkGeometryFilter>::New();
geometry->SetInputConnection(selector->GetOutputPort());
vtkSmartPointer<vtkXMLPolyDataWriter> writer =
vtkSmartPointer<vtkXMLPolyDataWriter>::New();
writer->SetInputConnection(geometry->GetOutputPort());
for (int i = 0; i < dicer->GetNumberOfActualPieces(); ++i)
{
std::stringstream pieceName;
pieceName << filename << "_" << i + 1 << extension;
selector->ThresholdBetween(i, i);
writer->SetFileName(pieceName.str().c_str());
writer->Write();
}
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(SplitPolyData)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(SplitPolyData MACOSX_BUNDLE SplitPolyData.cxx)
target_link_libraries(SplitPolyData ${VTK_LIBRARIES})
Download and Build SplitPolyData
Click here to download SplitPolyData and its CMakeLists.txt file. Once the tarball SplitPolyData.tar has been downloaded and extracted,
cd SplitPolyData/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:
./SplitPolyData
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.