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<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Dear colleagues,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Here attached is a vtk filter that extracts
silhouette edges from a poly data.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Silhouette of a surface is made of lines lying on the
surface where the surface normal is orthogonal to a direction.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Such edges are useful to produce CAD or sketch like
drawings. It can be combined with a constant colored surface rendering to hide non-visible
edges.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Attached example images are made from an iso-surface,
but much nicer results are achieved when working with lagrangian numerical simulations.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><u><font size=2 face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial'><o:p><span style='text-decoration:
none'> </span></o:p></span></font></u></p>
<p class=MsoNormal><u><font size=2 face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial'>Usage:<o:p></o:p></span></font></u></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Pipeline: vtkPolyData </span></font><font size=2
face=Wingdings><span lang=EN-US style='font-size:10.0pt;font-family:Wingdings'>à</span></font><font
size=2 face=Arial><span lang=EN-US style='font-size:10.0pt;font-family:Arial'> <b><span
style='font-weight:bold'>vtkPolyDataSilhouette</span></b> </span></font><font
size=2 face=Wingdings><span lang=EN-US style='font-size:10.0pt;font-family:
Wingdings'>à</span></font><font size=2 face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial'> vtkPolyDataMapper </span></font><font
size=2 face=Wingdings><span lang=EN-US style='font-size:10.0pt;font-family:
Wingdings'>à</span></font><font size=2 face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial'> vtkActor<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Parameters: SpecifiedVector and CameraVector modes
use a uniform direction (resp. explicit or from a camera), while
SpecifiedOrigin and CameraOrigin modes use the origin-to-center-of-the-edge
direction. CameraOrigin mode is the one to use to produce sketch like drawings.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>tips: try to combine black silhouettes edges (with
line width between 1 and 3) with different kinds of surface base renderings (with
or without lighting, constant colored or one color per material). It emphasizes
very well the shape of some phenomena, especially for numerical simulations.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Note: Silhouette edges can also serve to generate
shadow volumes, but this would need an additional contribution.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><u><font size=2 face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial'>Contribution :<o:p></o:p></span></font></u></p>
<p class=MsoNormal><u><font size=2 face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial'><o:p><span style='text-decoration:
none'> </span></o:p></span></font></u></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>Author:<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-indent:35.4pt'><font size=2 face=Arial><span
lang=EN-US style='font-size:10.0pt;font-family:Arial'>Thierry Carrard<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-indent:35.4pt'><font size=2 face=Arial><span
lang=EN-US style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Affiliation:<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-indent:35.4pt'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Commissariat à l’Energie
Atomique (CEA), Direction des Applications Militaires, Département des Sciences
de l’Information et de <st1:PersonName ProductID="la Simulation." w:st="on">la
Simulation.</st1:PersonName><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-indent:35.4pt'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>BP12, 91680 Bruyères Le Chatel, France.<o:p></o:p></span></font></p>
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