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Hi Karthik,<br>
<br>
Let me tell you a bit more about the process Nicolas is implementing:<br>
<ol>
<li>Run a level set on a 2D image</li>
<li>Apply vtkContourFilter or vtkMarchignSquares</li>
<li>Decimate the resulting vtkPolyData using vtkDecimatePolyline</li>
<li>Initialize the contour widget with the resulting polydata<br>
</li>
</ol>
In such a pipeline when initializing the contour widget, the input
polydata points can not be in order, and then we finally ended
iterating on the line to sort the order of the point container.<br>
<br>
So, I wonder do you think it could be included in the
vtkContourRepresentation class?<br>
<br>
Thanks,<br>
Arnaud<br>
<br>
On 05/07/2010 01:49 PM, Karthik Krishnan wrote:
<blockquote
cite="mid:y2z9ddb27261005071049m6197d58ar30143f17a1dc30b4@mail.gmail.com"
type="cite">Yes, that surely explains the behaviour Nicolas is
getting. The way to look at the initialization for the contour widget
is that its initializing the control points. The input is sort of
assumed to a vtkPolyData containing a single vtkPolyline cell. (in
which case, the points would have been in order). <br>
<br>
<br>
<br>
<div class="gmail_quote">On Fri, May 7, 2010 at 11:35 AM, Arnaud
GELAS <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:arnaud_gelas@hms.harvard.edu">arnaud_gelas@hms.harvard.edu</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi
guys,<br>
<br>
I was looking at the code of vtkContourWidget::Initialize and thus
vtkContourRepresentation::Initialize method, and it seems that the
initialization does not take into account the connectivity information
stored into the input polydata.<br>
For instance, vtkContourRepresentation appends to the node container
points from the input polydata in the same order of the points
container.<br>
<br>
In vtkContourRepresentation.cxx<br>
<br>
1217 for ( vtkIdType i=0; i < nPoints; i++ )<br>
1218 {<br>
1219 double *p = points->GetPoint( i );<br>
1220 this->AddNodeAtWorldPosition( p, worldOrient );<br>
1221 }<br>
<br>
I guess such a behavior may explain why Nicolas gets such results when
passing a contour resulting from a marching squares to a contour widget.<br>
<br>
<a moz-do-not-send="true"
href="http://www.vtk.org/pipermail/vtkusers/2010-May/108826.html"
target="_blank">http://www.vtk.org/pipermail/vtkusers/2010-May/108826.html</a><br>
<br>
I just wonder if it is supposed to be the normal behavior?<br>
and if not what would be the best way to fix it?<br>
assuming the polydata contains lines? assuming the input comes from a
vtkStripper?<br>
<br>
Thanks,<br>
Best,<br>
<font color="#888888">Arnaud<br>
<br>
<br>
</font></blockquote>
</div>
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<br>
</blockquote>
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