CellTreeLocator

VTKExamples/Cxx/PolyData/CellTreeLocator

Code

CellTreeLocator.cxx

#include <vtkPolyData.h>
#include <vtkSphereSource.h>
#include <vtkSmartPointer.h>
#include <vtkUnstructuredGrid.h>
#include <vtkCellTreeLocator.h>
#include <vtkGenericCell.h>

int main(int, char *[])
{
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetCenter(0.0, 0.0, 0.0);
  sphereSource->SetRadius(1.0);
  sphereSource->Update();


  // Create the tree
  vtkSmartPointer<vtkCellTreeLocator> cellTree =
    vtkSmartPointer<vtkCellTreeLocator>::New();
  cellTree->SetDataSet(sphereSource->GetOutput());
  cellTree->BuildLocator();

  double testInside[3] = {.5, 0.0, 0.0};
  double testOutside[3] = {10.0, 0.0, 0.0};

  double pcoords[3], weights[3];

  vtkIdType cellId;

  vtkSmartPointer<vtkGenericCell> cell = vtkSmartPointer<vtkGenericCell>::New();

  int returnValue = EXIT_SUCCESS;

  // Should be inside
  cellId = cellTree->FindCell(testInside,0,
                              cell, pcoords, weights);
  if (cellId>=0)
  {
    std::cout << "First point: in cell " << cellId << std::endl;
  }
  else
  {
    std::cout << "ERROR: Cell was not found but should have been." << std::endl;
    returnValue = EXIT_FAILURE;
  }

  // Should be outside
  cellId = cellTree->FindCell(testOutside,0,
                            cell, pcoords, weights);
  if (cellId>=0)
  {
    std::cout << "ERROR: Found point in cell " << cellId
              << " but it should be outside the domain." << std::endl;
    returnValue = EXIT_FAILURE;
  }
  else
  {
    std::cout << "Second point: outside" << std::endl;
  }

  return returnValue;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(CellTreeLocator)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(CellTreeLocator MACOSX_BUNDLE CellTreeLocator.cxx )

target_link_libraries(CellTreeLocator ${VTK_LIBRARIES})

Download and Build CellTreeLocator

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

cd CellTreeLocator/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:

./CellTreeLocator

WINDOWS USERS

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