If vtkStripper works most of the time, but not all the time, it might be a tolerance issue. What I mean is, the endpoints for the line segments might not match exactly.<div><br></div><div>You could try using vtkCleanPolyData with SetTolerance(1e-6) before vtkStripper. This will merge all nearly-coincident points.</div>
<div><br></div><div> David</div><div><br><div><br><div class="gmail_quote">On Thu, Jan 6, 2011 at 6:55 AM, Nicolas Sarrasin <span dir="ltr"><<a href="mailto:nsarrasin@phenix-systems.com">nsarrasin@phenix-systems.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div></div><div class="h5">
<div bgcolor="#ffffff" text="#003333">
<font size="-1"><font face="Tahoma">Yes of course !<br>
<br>
That's why I'm writing "</font></font><small>For most of case it
works well", vtkStripper helps me a lot.<br>
<br>
But with this example, my convertion fails.<br>
<br>
With debug, I found that the secondth (and last) line close the
arc of circle but when I display it, this doesn't appear, as it's
shown in the pictures I linked.<br>
<br>
</small>Le 06/01/2011 14:47, David Gobbi a écrit :
<blockquote type="cite">
<pre>Hi Nicolas,
In my last email to you, I recommended the vtkStripper filter for
generating a polyline from line segments. Did you try it?
Cheers,
David
On Thu, Jan 6, 2011 at 3:30 AM, Nicolas Sarrasin
<a href="mailto:nsarrasin@phenix-systems.com" target="_blank"><nsarrasin@phenix-systems.com></a> wrote:
</pre>
<blockquote type="cite">
<pre>Hi all,
I'm trying to convert a set of line into one only vtkPolyLine. (original
post here :
<a href="http://vtk.1045678.n5.nabble.com/construct-a-vtkPolyLine-PolyGon-from-a-set-of-vtkLines-td3325716.html" target="_blank">http://vtk.1045678.n5.nabble.com/construct-a-vtkPolyLine-PolyGon-from-a-set-of-vtkLines-td3325716.html</a>)
I go through all the polylines of vtkPolyData->GetLines() and then get the
associated points.
For most of case it works well, but I'm actually encounter a problem on a
case.
The input polydata
(<a href="http://img525.imageshack.us/img525/8370/vtkconvertioninit.png" target="_blank">http://img525.imageshack.us/img525/8370/vtkconvertioninit.png</a>) is composed
of two lines which trace an arc of circle.
After the convertion, this arc is closed
(<a href="http://img502.imageshack.us/img502/8773/vtkconvertionres.png" target="_blank">http://img502.imageshack.us/img502/8773/vtkconvertionres.png</a>).
It comes from the second line which might not be correct.
Can someone explain me what is going wrong ?
Thanks by advance.
Here is a c++ sample code with the input file attached (wire.vtp).
****
#include <vtkSmartPointer.h>
#include <vtkCellArray.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkPolyLine.h>#include <vtkSmartPointer.h>
#include <vtkCellArray.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkPolyLine.h>
int main (int argc, char *argv[])
{
vtkSmartPointer<vtkXMLPolyDataReader> reader =
vtkSmartPointer<vtkXMLPolyDataReader>::New();
reader->SetFileName("./wire.vtp");
vtkSmartPointer<vtkPolyData> init_data =
vtkSmartPointer<vtkPolyData>::New();
init_data = reader->GetOutput();
vtkSmartPointer<vtkPoints> init_points =
vtkSmartPointer<vtkPoints>::New();
init_points=init_data->GetPoints();
vtkSmartPointer<vtkCellArray> init_lineArray =
vtkSmartPointer<vtkCellArray>::New();
init_lineArray = init_data->GetLines();
int nblines = init_lineArray->GetNumberOfCells();
vtkSmartPointer<vtkPolyData> new_data =
vtkSmartPointer<vtkPolyData>::New();
vtkSmartPointer<vtkPoints> new_points =
vtkSmartPointer<vtkPoints>::New();
vtkSmartPointer<vtkPolyLine> polyline =
vtkSmartPointer<vtkPolyLine>::New();
vtkSmartPointer<vtkCellArray> new_lineArray =
vtkSmartPointer<vtkCellArray>::New();
double coords[3];
vtkIdType nbpts=0, *pts=0;
for( init_lineArray->InitTraversal(); init_lineArray->GetNextCell(nbpts,
pts);)
{
vtkIdType init_ind=0, new_ind=0;
for(int p=0; p<nbpts; p++)
{
init_ind=pts[p];
if(init_ind<0)
continue;
init_points->GetPoint( init_ind, coords);
new_ind=new_points->InsertNextPoint(coords);
polyline->GetPointIds()->InsertNextId(new_ind);
}
}
new_lineArray->InsertNextCell(polyline);
new_data->SetPoints(new_points);
new_data->SetLines(new_lineArray);
vtkSmartPointer<vtkXMLPolyDataWriter> writer =
vtkSmartPointer<vtkXMLPolyDataWriter>::New();
writer->SetFileName("./new_wire.vtp");
writer->SetInput(new_data);
writer->Write();
****
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