PolygonIntersection
VTKExamples/Cxx/GeometricObjects/PolygonIntersection
Code
PolygonIntersection.cxx
#include <vtkSmartPointer.h>
#include <vtkPoints.h>
#include <vtkPolygon.h>
int main(int, char*[])
{
// Create a square in the XY plane
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(0.0, 0.0, 0.0);
points->InsertNextPoint(1.0, 0.0, 0.0);
points->InsertNextPoint(1.0, 1.0, 0.0);
points->InsertNextPoint(0.0, 1.0, 0.0);
// Create the polygon
vtkSmartPointer<vtkPolygon> polygon = vtkSmartPointer<vtkPolygon>::New();
polygon->GetPoints()->DeepCopy(points);
polygon->GetPointIds()->SetNumberOfIds(4); // 4 corners of the square
polygon->GetPointIds()->SetId(0, 0);
polygon->GetPointIds()->SetId(1, 1);
polygon->GetPointIds()->SetId(2, 2);
polygon->GetPointIds()->SetId(3, 3);
// Inputs
double p1[3] = {0.1, 0, -1.0};
double p2[3] = {0.1, 0, 1.0};
double tolerance = 0.001;
// Outputs
double t; // Parametric coordinate of intersection (0 (corresponding to p1) to 1 (corresponding to p2))
double x[3]; // The coordinate of the intersection
double pcoords[3];
int subId;
vtkIdType iD = polygon->IntersectWithLine(p1, p2, tolerance, t, x, pcoords, subId);
std::cout << "intersected? " << iD << std::endl;
std::cout << "intersection: " << x[0] << " " << x[1] << " " << x[2] << std::endl;
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(PolygonIntersection)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(PolygonIntersection MACOSX_BUNDLE PolygonIntersection.cxx)
target_link_libraries(PolygonIntersection ${VTK_LIBRARIES})
Download and Build PolygonIntersection
Click here to download PolygonIntersection and its CMakeLists.txt file. Once the tarball PolygonIntersection.tar has been downloaded and extracted,
cd PolygonIntersection/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:
./PolygonIntersection
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.