KdTreePointLocatorClosestPoint
VTKExamples/Cxx/DataStructures/KdTreePointLocatorClosestPoint
Description
This example creates a set of three points, builds a KDTree from them, then demonstrates how to find the closest point to a query point.
Code
KdTreePointLocatorClosestPoint.cxx
#include <vtkSmartPointer.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkIdList.h>
#include <vtkKdTreePointLocator.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);
vtkSmartPointer<vtkPolyData> polydata =
vtkSmartPointer<vtkPolyData>::New();
polydata->SetPoints(points);
// Create the tree
vtkSmartPointer<vtkKdTreePointLocator> kDTree =
vtkSmartPointer<vtkKdTreePointLocator>::New();
kDTree->SetDataSet(polydata);
kDTree->BuildLocator();
double testPoint[3] = {2.0, 0.0, 0.0};
// Find the closest points to TestPoint
vtkIdType iD = kDTree->FindClosestPoint(testPoint);
std::cout << "The closest point is point " << iD << std::endl;
//Get the coordinates of the closest point
double closestPoint[3];
kDTree->GetDataSet()->GetPoint(iD, closestPoint);
std::cout << "Coordinates: " << closestPoint[0] << " " << closestPoint[1] << " " << closestPoint[2] << std::endl;
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(KdTreePointLocatorClosestPoint)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(KdTreePointLocatorClosestPoint MACOSX_BUNDLE KdTreePointLocatorClosestPoint.cxx)
target_link_libraries(KdTreePointLocatorClosestPoint ${VTK_LIBRARIES})
Download and Build KdTreePointLocatorClosestPoint
Click here to download KdTreePointLocatorClosestPoint and its CMakeLists.txt file. Once the tarball KdTreePointLocatorClosestPoint.tar has been downloaded and extracted,
cd KdTreePointLocatorClosestPoint/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:
./KdTreePointLocatorClosestPoint
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.