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KDTreeFindPointsWithinRadius

vtk-examples/Cxx/DataStructures/KDTreeFindPointsWithinRadius

Question

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Code

KDTreeFindPointsWithinRadius.cxx

#include <vtkCellArray.h>
#include <vtkIdList.h>
#include <vtkKdTreePointLocator.h>
#include <vtkNew.h>
#include <vtkPointSource.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>

int main(int, char*[])
{
  // Create some random points
  vtkNew<vtkPointSource> pointSource;
  pointSource->SetNumberOfPoints(10);
  pointSource->Update();

  // Create the tree
  vtkNew<vtkKdTreePointLocator> pointTree;
  pointTree->SetDataSet(pointSource->GetOutput());
  pointTree->BuildLocator();

  // Find the k closest points to (0,0,0)
  vtkIdType k = 1;
  double testPoint[3] = {0.0, 0.0, 0.0};
  vtkNew<vtkIdList> result;

  pointTree->FindPointsWithinRadius(1.0, testPoint, result);

  for (vtkIdType i = 0; i < k; i++)
  {
    vtkIdType point_ind = result->GetId(i);
    double p[3];
    pointSource->GetOutput()->GetPoint(point_ind, p);
    std::cout << "Closest point " << i << ": Point " << point_ind << ": ("
              << p[0] << ", " << p[1] << ", " << p[2] << ")" << std::endl;
  }

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(KDTreeFindPointsWithinRadius)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersSources
  QUIET
)

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

Download and Build KDTreeFindPointsWithinRadius

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

cd KDTreeFindPointsWithinRadius/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:

./KDTreeFindPointsWithinRadius

WINDOWS USERS

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