<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">I have had the same problems using the triangulation routines from ParaView/VTK. I ended up using some Delaunay Triangulation Code from the "Quake" Project at CMU and turning that code into a ParaView Filter (or at least trying to). I have had decent success with this approach. The filter works for most cases I throw at it but there are some cases where my algorithm is not properly preparing the input dataset.<DIV><BR class="khtml-block-placeholder"></DIV><DIV><A href="http://www.cs.cmu.edu/~quake/triangle.html">http://www.cs.cmu.edu/~quake/triangle.html</A></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><A href="http://cm.bell-labs.com/netlib/voronoi/triangle.zip">http://cm.bell-labs.com/netlib/voronoi/triangle.zip</A></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>So, basically, you are probably on your own for writing/implementing/borrowing better triangulation code.</DIV><DIV><BR><DIV> <SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Bitstream Vera Sans; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">-- </DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Mike Jackson Senior Research Engineer</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Innovative Management & Technology Services</DIV><BR class="Apple-interchange-newline"></SPAN> </DIV><BR><DIV><DIV>On Oct 2, 2007, at 11:49 AM, Bob Anderson wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"> <DIV class="Section1"><P class="MsoNormal"><FONT size="2" face="Arial"><SPAN style="font-size:10.0pt; font-family:Arial">For polygons with lobes, the tests I’ve done with ParaView don’t give correct surface triangulation.</SPAN></FONT></P><P class="MsoNormal"><FONT size="2" face="Arial"><SPAN style="font-size:10.0pt; font-family:Arial">In the case where the object comes from my custom reader, using output->SetPolys(myCellsPtr); it produces a surface that doesn’t stay within the polygon boundary, and applying the Delaunay2D filter to the polyline object (SamplePolygon1Cell.vtk) also ‘blobbs’ the polygon.</SPAN></FONT></P><P class="MsoNormal"><FONT size="2" face="Arial"><SPAN style="font-size:10.0pt; font-family:Arial">See attachments –a correct surface triangulation (SamplePolySurface.jpg), and the ParaView result (PV_Delaunay2D_Polygon.jpg)</SPAN></FONT></P><P class="MsoNormal"><FONT size="2" face="Arial"><SPAN style="font-size:10.0pt; font-family:Arial">I’m currently doing my own triangulation using ‘hgrd_src’ routines from CodeProject, but if there is a better way to get the correct results within ParaView I’d be happy to try it.</SPAN></FONT></P><DIV><FONT size="2" face="Arial"><SPAN style="font-size:10.0pt; font-family:Arial"> </SPAN></FONT><BR class="khtml-block-placeholder"></DIV><DIV style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; "><FONT size="2" face="Arial"><SPAN style="font-size:10.0pt;font-family:Arial">Bob Anderson</SPAN></FONT></DIV><DIV style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; "><FONT size="2" face="Times New Roman"><SPAN style="font-size:10.0pt">MIRARCO Mining Innovation</SPAN></FONT></DIV><DIV style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; "><FONT size="2" face="Times New Roman"><SPAN style="font-size:10.0pt">Laurentian University</SPAN></FONT></DIV><DIV><FONT size="3" face="Times New Roman"><SPAN style="font-size: 12.0pt"> </SPAN></FONT><BR class="khtml-block-placeholder"></DIV> </DIV> <SPAN><DIV><PV_Delaunay2D_Polygon.jpg></DIV></SPAN><SPAN><DIV><SamplePolygon1Cell.vtk></DIV></SPAN><SPAN><DIV><SamplePolySurface.jpg></DIV></SPAN><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">_______________________________________________</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">ParaView mailing list</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><A href="mailto:ParaView@paraview.org">ParaView@paraview.org</A></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><A href="http://www.paraview.org/mailman/listinfo/paraview">http://www.paraview.org/mailman/listinfo/paraview</A></DIV> </BLOCKQUOTE></DIV><BR></DIV></BODY></HTML>