OBBTreeIntersectWithLine
VTKExamples/Cxx/DataStructures/OBBTreeIntersectWithLine
Description
vtkOBBTree returns ALL intersections with a line and the dataset. If you want the closest intersection, you must manually find it. In this example, we create a sphere and intersect a single line with it.
Code
OBBTreeIntersectWithLine.cxx
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPointData.h>
#include <vtkLine.h>
#include <vtkOBBTree.h>
int main(int, char *[])
{
vtkSmartPointer<vtkSphereSource> sphereSource =
vtkSmartPointer<vtkSphereSource>::New();
sphereSource->Update();
// Create the locator
vtkSmartPointer<vtkOBBTree> tree =
vtkSmartPointer<vtkOBBTree>::New();
tree->SetDataSet(sphereSource->GetOutput());
tree->BuildLocator();
// Intersect the locator with the line
double lineP0[3] = {0.0, 0.0, 0.0};
double lineP1[3] = {0.0, 0.0, 2.0};
vtkSmartPointer<vtkPoints> intersectPoints =
vtkSmartPointer<vtkPoints>::New();
tree->IntersectWithLine(lineP0, lineP1, intersectPoints, NULL);
std::cout << "NumPoints: " << intersectPoints->GetNumberOfPoints()
<< std::endl;
// Display list of intersections
double intersection[3];
for(int i = 0; i < intersectPoints->GetNumberOfPoints(); i++ )
{
intersectPoints->GetPoint(i, intersection);
std::cout << "Intersection " << i << ": "
<< intersection[0] << ", "
<< intersection[1] << ", "
<< intersection[2] << std::endl;
}
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(OBBTreeIntersectWithLine)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(OBBTreeIntersectWithLine MACOSX_BUNDLE OBBTreeIntersectWithLine.cxx)
target_link_libraries(OBBTreeIntersectWithLine ${VTK_LIBRARIES})
Download and Build OBBTreeIntersectWithLine
Click here to download OBBTreeIntersectWithLine and its CMakeLists.txt file. Once the tarball OBBTreeIntersectWithLine.tar has been downloaded and extracted,
cd OBBTreeIntersectWithLine/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:
./OBBTreeIntersectWithLine
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.