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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>AFAIK Open <span class=SpellE>gl</span>
does not guarantee that concave polygons would be rendered <span class=GramE>correctly,</span>
the question is does <span class=SpellE>vtk</span> has a class/filter that
would take a polygonal data and split the concave polygons into a set of convex
one &#8211; and do it efficiently that is without doing excessive split.<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>The same for the second Q &#8211; does <span
class=SpellE>vtk</span> has the facilities to detect a concave polygon so I don&#8217;t
have to reinvent it.<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'>-----Original Message-----<br>
<b><span style='font-weight:bold'>From:</span></b> Andrew J. P. Maclean
[mailto:a.maclean@acfr.usyd.edu.au] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, June 24, 2002 1:29
AM<br>
<b><span style='font-weight:bold'>To:</span></b> 'sagi schein'<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [vtkusers] concave
polygons</span></font></p>

<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal style='margin-left:.5in'><font size=2 color=navy face=Arial><span
lang=EN-AU style='font-size:10.0pt;font-family:Arial;color:navy;mso-ansi-language:
EN-AU'>If I understand the questions:</span></font><span lang=EN-AU
style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:.5in'><font size=2 color=navy face=Arial><span
lang=EN-AU style='font-size:10.0pt;font-family:Arial;color:navy;mso-ansi-language:
EN-AU'>1: No &#8211; they are geometrically distinct.</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:.5in'><font size=2 color=navy face=Arial><span
lang=EN-AU style='font-size:10.0pt;font-family:Arial;color:navy;mso-ansi-language:
EN-AU'>2: Look at the curvatures &#8211; a differential geometry book should
give you some examples of how to do this.</span></font><span lang=EN-AU
style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:.5in'><font size=2 color=navy face=Arial><span
lang=EN-AU style='font-size:10.0pt;font-family:Arial;color:navy;mso-ansi-language:
EN-AU'>&nbsp;</span></font><span lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<div>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>___________________________________________</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>Andrew J. P. Maclean</span></font><span lang=EN-AU
style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>Postal:</span></font><span lang=EN-AU
style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>Australian Centre for Field Robotics</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>The Rose Street Building J04</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>The University of Sydney&nbsp; 2006&nbsp; NSW</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>AUSTRALIA</span></font><span lang=EN-AU
style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
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mso-ansi-language:EN-AU'>&nbsp;</span></font><span lang=EN-AU style='mso-ansi-language:
EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>Room:&nbsp; 106</span></font><span lang=EN-AU
style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>Phone: +61 2 9351 3283</span></font><span lang=EN-AU
style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>Fax:&nbsp;&nbsp; +61 2 9351 7474</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
http://www.acfr.usyd.edu.au/</span></font><span lang=EN-AU style='mso-ansi-language:
EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>&nbsp;</span></font><span lang=EN-AU style='mso-ansi-language:
EN-AU'><o:p></o:p></span></p>

<p class=MsoAutoSig style='margin-left:.5in'><font size=3 color=navy
face="Times New Roman"><span lang=EN-AU style='font-size:12.0pt;color:navy;
mso-ansi-language:EN-AU'>___________________________________________</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

</div>

<p class=MsoNormal style='margin-left:.5in'><font size=2 color=navy face=Arial><span
lang=EN-AU style='font-size:10.0pt;font-family:Arial;color:navy;mso-ansi-language:
EN-AU'>&nbsp;</span></font><span lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:1.0in'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'>-----Original Message-----<br>
<b><span style='font-weight:bold'>From:</span></b>
vtkusers-admin@public.kitware.com [mailto:vtkusers-admin@public.kitware.com] <b><span
style='font-weight:bold'>On Behalf Of </span></b>sagi schein<br>
<b><span style='font-weight:bold'>Sent:</span></b> Saturday, 22 June 2002 16:02<br>
<b><span style='font-weight:bold'>To:</span></b> vtkusers@public.kitware.com<br>
<b><span style='font-weight:bold'>Subject:</span></b> [vtkusers] concave
polygons</span></font><span lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:1.0in'><font size=3 face="Times New Roman"><span
lang=EN-AU style='font-size:12.0pt;mso-ansi-language:EN-AU'>&nbsp;<o:p></o:p></span></font></p>

<p class=MsoNormal style='margin-left:1.0in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Is there any to </span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:1.5in;text-indent:-.25in'><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>1.</span></font><font
size=1><span style='font-size:7.0pt'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Generate
convex polygon(s) out of a concave polygon using vtk?</span></font><span
lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:1.5in;text-indent:-.25in'><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>2.</span></font><font
size=1><span style='font-size:7.0pt'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Identify
concave polygons?</span></font><span lang=EN-AU style='mso-ansi-language:EN-AU'><o:p></o:p></span></p>

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