# [vtkusers] A problem with ConstrainedDelaunay2D

zhq 15891495523 at 126.com
Tue Sep 22 11:25:44 EDT 2015

```sorry, My code is :

#include <vtkVersion.h>
#include <vtkCellArray.h>
#include <vtkProperty.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolygon.h>
#include <vtkSmartPointer.h>
#include <vtkDelaunay2D.h>
#include <vtkMath.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>

#define PI 3.1415926

int main(int, char *[])
{
// Generate a 10 x 10 grid of points
vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();
/*for(unsigned int x = 0; x < 10; x++)
{
for(unsigned int y = 0; y < 10; y++)
{
points->InsertNextPoint(x + vtkMath::Random(-.25, .25),
y + vtkMath::Random(-.25,.25),
0);
}
}*/
for (int theta = 0;theta<360;theta++)
{
double x = 2*cos(theta*PI/180);
double y = 2*sin(theta*PI/180);
points->InsertNextPoint(x,y,0);
}

for (int theta = 0;theta<360;theta++)
{
double x = cos(theta*PI/180);
double y = sin(theta*PI/180);
points->InsertNextPoint(x,y,0);
}
vtkSmartPointer<vtkPolyData> aPolyData =
vtkSmartPointer<vtkPolyData>::New();
aPolyData->SetPoints(points);

// Create a cell array to store the polygon in
vtkSmartPointer<vtkCellArray> aCellArray =
vtkSmartPointer<vtkCellArray>::New();

// Define a polygonal hole with a clockwise polygon
vtkSmartPointer<vtkPolygon> aPolygon =
vtkSmartPointer<vtkPolygon>::New();

/*for (int i=0;i<360;i++)
{
aPolygon->GetPointIds()->InsertNextId(i+360);
}*/
double x[3];
/*aPolygon->GetPointIds()->InsertNextId(22);
aPolygon->GetPointIds()->InsertNextId(23);
aPolygon->GetPointIds()->InsertNextId(24);
aPolygon->GetPointIds()->InsertNextId(25);
aPolygon->GetPointIds()->InsertNextId(35);
aPolygon->GetPointIds()->InsertNextId(45);
aPolygon->GetPointIds()->InsertNextId(44);
aPolygon->GetPointIds()->InsertNextId(43);
aPolygon->GetPointIds()->InsertNextId(42);
aPolygon->GetPointIds()->InsertNextId(32);*/

aCellArray->InsertNextCell(aPolygon);

// Create a polydata to store the boundary. The points must be the
// same as the points we will triangulate.
vtkSmartPointer<vtkPolyData> boundary =
vtkSmartPointer<vtkPolyData>::New();
boundary->SetPoints(aPolyData->GetPoints());
boundary->SetPolys(aCellArray);

boundary->GetPoint(1,x);
int n = boundary->GetPoints()->GetNumberOfPoints();
for (int i=0;i<n;i++)
{
boundary->GetPoint(i,x);
}

// Triangulate the grid points
vtkSmartPointer<vtkDelaunay2D> delaunay =
vtkSmartPointer<vtkDelaunay2D>::New();
#if VTK_MAJOR_VERSION <= 5
delaunay->SetInput(aPolyData);
delaunay->SetSource(boundary);
#else
delaunay->SetInputData(aPolyData);
delaunay->SetSourceData(boundary);
#endif
delaunay->Update();

// Visualize
vtkSmartPointer<vtkPolyDataMapper> meshMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
meshMapper->SetInputConnection(delaunay->GetOutputPort());

vtkSmartPointer<vtkActor> meshActor =
vtkSmartPointer<vtkActor>::New();
meshActor->SetMapper(meshMapper);
//meshActor->GetProperty()->SetEdgeColor(0,0,1); // Why aren't the edges
aren't visible unless we set the representation to wireframe?
//meshActor->GetProperty()->SetInterpolationToFlat();
meshActor->GetProperty()->SetRepresentationToWireframe();

vtkSmartPointer<vtkPolyDataMapper> boundaryMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
#if VTK_MAJOR_VERSION <= 5
boundaryMapper->SetInputConnection(boundary->GetProducerPort());
#else
boundaryMapper->SetInputData(boundary);
#endif

vtkSmartPointer<vtkActor> boundaryActor =
vtkSmartPointer<vtkActor>::New();
boundaryActor->SetMapper(boundaryMapper);
boundaryActor->GetProperty()->SetColor(1,0,0);

// Create a renderer, render window, and interactor
vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);

// Add the actor to the scene
renderer->SetBackground(.3, .6, .3); // Background color green

// Render and interact
renderWindow->Render();
renderWindowInteractor->Start();

return EXIT_SUCCESS;
}

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```