[vtkusers] How to set the boundary of vtkDelaunay2D ?

[zhq]

Dear all:

     I want to triangulate some points with a boundary. And I find a
example:
http://www.vtk.org/Wiki/VTK/Examples/Cxx/Filtering/ConstrainedDelaunay2D

     In fact, when I want to test the method in circle (input the data at
30~42 in the code), I actually get:
<http://vtk.1045678.n5.nabble.com/file/n5734142/1.png> 

     And I want to remove those line inside the inner circle. And when I set
the inner circle points as the boundary ( line 55~58 in the code ), I can't
get what I want.

    Could somebody give me some tips ? Thank you very much in advance !

    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+=10)
	{
		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+=10)
	{
		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=36;i<72;i++)
	{
		aPolygon->GetPointIds()->InsertNextId(i);
	}*/
	/*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);

	// 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();
	renderWindow->AddRenderer(renderer);
	vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
		vtkSmartPointer<vtkRenderWindowInteractor>::New();
	renderWindowInteractor->SetRenderWindow(renderWindow);

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

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

	return EXIT_SUCCESS;
}

ZhangQiang



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