KdTree

VTKExamples/Cxx/DataStructures/KdTree

Description

This example demonstrates how to use vtkKdTree to build a tree from a vtkPoints object. Note that since AddDataSet or SetDataSet were not called, you cannot use GetDataSet.

Code

KdTree.cxx

#include <vtkSmartPointer.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkIdList.h>
#include <vtkKdTree.h>
#include <vtkVertexGlyphFilter.h>

int main(int, char *[])
{
  //Setup point coordinates
  double x[3] = {1.0, 0.0, 0.0};
  double y[3] = {0.0, 1.0, 0.0};
  double z[3] = {0.0, 0.0, 1.0};

  vtkSmartPointer<vtkPoints> points = 
    vtkSmartPointer<vtkPoints>::New();
  points->InsertNextPoint(x);
  points->InsertNextPoint(y);
  points->InsertNextPoint(z);

  //Create the tree
  vtkSmartPointer<vtkKdTree> kDTree = 
    vtkSmartPointer<vtkKdTree>::New();
  kDTree->BuildLocatorFromPoints(points);

  double testPoint[3] = {2.0, 0.0, 0.0};

  //Find the closest points to TestPoint
  double closestPointDist;
  vtkIdType id = kDTree->FindClosestPoint(testPoint, closestPointDist); //vtkKdTree::FindClosestPoint: must build locator first
  std::cout << "The closest point is point " << id << std::endl;

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(KdTree)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersGeneral QUIET)
if (NOT VTK_FOUND)
  message("Skipping KdTree: ${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(KdTree MACOSX_BUNDLE KdTree.cxx )
  target_link_libraries(KdTree PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(KdTree MACOSX_BUNDLE KdTree.cxx )
  target_link_libraries(KdTree PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS KdTree
    MODULES ${VTK_LIBRARIES}
    )
endif () 

Download and Build KdTree

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

cd KdTree/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:

./KdTree

WINDOWS USERS

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