[vtkusers] Wrong BoundaryEdge output from vtkFeatureEdges

[Anuwat Dechvijankit]

Hi all vtkusers,

First post here.
I have wrong output result from vtkFeatureEdges filtering BoundaryEdge only.
(on vtk 6.1  x64 windows 8.1)

here is sample code:

#include <vtkSmartPointer.h>
#include <vtkPlaneSource.h>
#include <vtkFeatureEdges.h>
#include <vtkCellArray.h>
#include <vtkLine.h>
#include <ostream>

int _tmain(int argc, _TCHAR* argv[])
{
    vtkSmartPointer<vtkPlaneSource> planeSource = vtkSmartPointer<vtkPlaneSource>::New();    
    planeSource->SetXResolution(4);
    planeSource->SetYResolution(4);
    planeSource->SetCenter(0,0,0);
    planeSource->SetNormal(0.0, 0.0, 1.0);
    planeSource->Update();    
    vtkSmartPointer<vtkPolyData> polydata =  planeSource->GetOutput();
    std::cout << "Total points:" <<  polydata->GetNumberOfPoints() << endl;
    for (int i = 0; i < polydata->GetNumberOfPoints(); i++)
    {
        double pt[3];
        polydata->GetPoint(i , pt);
        std::cout << "Point:" <<  i << " \t(" <<pt[0]<<"," << pt[1] <<"," <<pt[2]<< ")" << endl;
    }
    vtkSmartPointer<vtkFeatureEdges> borderEdges = vtkSmartPointer<vtkFeatureEdges>::New();
    borderEdges->SetInputConnection(planeSource->GetOutputPort());
    borderEdges->FeatureEdgesOff();    
    borderEdges->ManifoldEdgesOff();
    borderEdges->NonManifoldEdgesOff();
    borderEdges->ColoringOff();
    borderEdges->BoundaryEdgesOn();
    borderEdges->Update();    
    vtkSmartPointer<vtkCellArray> lines= borderEdges->GetOutput()->GetLines();
    int numBorderEdges = lines->GetNumberOfCells();    
    std::cout << "Total border edges:" <<  numBorderEdges << endl;
    for(vtkIdType i = 0; i < numBorderEdges; i++)
    {    
        vtkLine* line = vtkLine::SafeDownCast(borderEdges->GetOutput()->GetCell(i));        
        int numID = line->GetPointIds()->GetNumberOfIds();
        int id0 = line->GetPointIds()->GetId(0);
        int id1 = line->GetPointIds()->GetId(1);
        std::cout << "B-edge:" << i <<"\t"<< numID <<"(" <<id0<<"," <<id1<<")"<< endl;
    }
    getchar();
    return 0;
}

report result is:
Total points:25
Point:0         (-0.5,-0.5,0)
Point:1         (-0.25,-0.5,0)
Point:2         (0,-0.5,0)
Point:3         (0.25,-0.5,0)
Point:4         (0.5,-0.5,0)
Point:5         (-0.5,-0.25,0)
Point:6         (-0.25,-0.25,0)
Point:7         (0,-0.25,0)
Point:8         (0.25,-0.25,0)
Point:9         (0.5,-0.25,0)
Point:10        (-0.5,0,0)
Point:11        (-0.25,0,0)
Point:12        (0,0,0)
Point:13        (0.25,0,0)
Point:14        (0.5,0,0)
Point:15        (-0.5,0.25,0)
Point:16        (-0.25,0.25,0)
Point:17        (0,0.25,0)
Point:18        (0.25,0.25,0)
Point:19        (0.5,0.25,0)
Point:20        (-0.5,0.5,0)
Point:21        (-0.25,0.5,0)
Point:22        (0,0.5,0)
Point:23        (0.25,0.5,0)
Point:24        (0.5,0.5,0)
Total border edges:16
B-edge:0        2(0,1)
B-edge:1        2(2,0)
B-edge:2        2(1,3)
B-edge:3        2(3,4)
B-edge:4        2(4,5)
B-edge:5        2(5,6)
B-edge:6        2(7,2)
B-edge:7        2(6,8)
B-edge:8        2(9,7)
B-edge:9        2(8,10)
B-edge:10       2(11,12)
B-edge:11       2(12,9)
B-edge:12       2(13,11)
B-edge:13       2(14,13)
B-edge:14       2(10,15)
B-edge:15       2(15,14)

as you see b-edges#2,#3 report wrong id pairs.
#4  reports wrong too.

Is it library bug ? or I have wrong coding?



best regards,

Anuwat
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20140801/b1e3cdd3/attachment.html>