You're setting the value of all 4 points to "1", and then taking a contour of 1. It doesn't intersect anywhere, so I think it's working just right.<br><br>Change the scalars to:<br> for (int i =0; i <4; i++) scalars->InsertNextValue(i);
<br><br>And then you'll have 4 different values.<br><br><div><span class="gmail_quote">On 2/1/06, <b class="gmail_sendername">Frederic DANESI</b> <<a href="mailto:fred.danesi@netcourrier.com">fred.danesi@netcourrier.com
</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Dear vtkusers,<br><br>I am trying something that I believe quite simple, but without any success.
<br><br>I would like to build some vtkPolygons (2D) and then to use vtkContourFilter<br>to obtain an isoline (which I assume to match with the boundary of all<br>polygons together) ...<br><br>Even with only one polygon, vtkContourFilter does not do anything
<br>(vtkContourFilter (09981DD8): Created: 0 points, 0 verts, 0 lines, 0<br>triangles) ...<br><br>I enclosed my code hereafter.<br><br>I will really appreciate any idea, tips on what I missed or what I'm doing<br>wrong, or any code example...
<br><br>Thanks,<br>Fred.<br><br>----<br><br>vtkPolygon *polygon = vtkPolygon::New();<br><br> polygon->GetPointIds()->SetNumberOfIds(4);<br> polygon->GetPointIds()->SetId(0,0);<br> polygon->GetPointIds()->SetId(1,1);
<br> polygon->GetPointIds()->SetId(2,2);<br> polygon->GetPointIds()->SetId(3,3);<br><br> polygon->GetPoints()->SetNumberOfPoints(4);<br> polygon->GetPoints()->SetPoint(0, 0.0, 0.0, 0.0);<br> polygon->GetPoints()->SetPoint(1,
10.0, 0.0, 0.0);<br> polygon->GetPoints()->SetPoint(2, 10.0, 10.0, 0.0);<br> polygon->GetPoints()->SetPoint(3, 0.0, 10.0, 0.0);<br><br> vtkIntArray * scalars = vtkIntArray::New();<br> scalars->Allocate(5000,10000);
<br> for (int i =0; i <4; i++) scalars->InsertNextValue(1);<br><br> vtkPolyData * polygonPolyData = vtkPolyData::New();<br> polygonPolyData->Allocate(1,1);<br> polygonPolyData->InsertNextCell(polygon->GetCellType(),
<br>polygon->GetPointIds());<br> polygonPolyData->SetPoints(polygon->GetPoints());<br> polygonPolyData->GetPointData()->SetScalars(scalars);<br><br> // mapping and rendering "polygonPolyData" ==> OK ...
<br><br> vtkContourFilter * flt = vtkContourFilter ::New();<br> flt->SetInput((vtkDataSet *)output);<br> flt->DebugOn();<br> flt->SetValue(0,1);<br><br> //+ mapping and rendering ==> vtkContourFilter (09981DD8): Created: 0
<br>points, 0 verts, 0 lines, 0 triangles ... empty ...<br><br>--<br>Responsable Département DINCCS<br>(Département Ingénierie Numérique Conception Collaborative et Simulation)<br>Pole de Haute Technologie<br>08000 Charleville-Mézières
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<br>-- <br>Randall Hand<br>Visualization Scientist, <br>ERDC-MSRC Vicksburg, MS<br>Homepage: <a href="http://www.yeraze.com">http://www.yeraze.com</a>