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<DIV><FONT face=Arial size=2>Hi Sebastien</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. Yes, you must link with GLU
lib</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>2. Use it freely</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>3. The GLU tesselator picks up which are external
and which are internal contours. It assigns winding numbers for points inside
contours - from the OpenGL programmers guide ... 'The winding number of a point
is the signed number of revolutions we make around that
point while travelling once around the contour (where a counterclockwise
revolution is +ve and a clockwise revolution is -ve). When there are
several contours, the individual winding numbers are summed.' I keep contours in
the same direction and use the winding rule to classify the regions. It's a lot
to get into an email - you should get your hands on the OpenGL programmers
guide (the Red Book) for a good explanation. My head's been elsewhere for a
few weeks but I'm about to start a project where I use the filter a lot so I'll
try and write some decent documentation</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I'm also working with VC++ 6 so you shouldn't
have any problems</FONT></DIV>
<DIV><FONT face=Arial size=2>I'm sending you the source and some scripts
directly</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Malcolm</FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>----- Original Message ----- </DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=maraux@ondim.fr href="mailto:maraux@ondim.fr">Sebastien MARAUX</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=malcolm@geovision.co.za
href="mailto:malcolm@geovision.co.za">Malcolm Drummond</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, March 14, 2003 12:36
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [vtkusers] (constrained)
delaunay2D issue</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Yes, I would appreciate it</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thank you</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. I guess I need to link with GL libs after
incorporating your </FONT></DIV>
<DIV><FONT face=Arial size=2>sources ?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>2. Can I use it freely (I mean in my company
for commercial </FONT></DIV>
<DIV><FONT face=Arial size=2>application) because I am </FONT><FONT face=Arial
size=2>looking for open and free solutions to tesselate polygons with
holes?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>3. are holes defined by negative orientation
polygons ?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks for your help</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Sebastien MARAUX</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=malcolm@geovision.co.za
href="mailto:malcolm@geovision.co.za">Malcolm Drummond</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=vtkusers@public.kitware.com
href="mailto:vtkusers@public.kitware.com">vtkusers</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, March 14, 2003 9:56
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [vtkusers] (constrained)
delaunay2D issue</DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial
size=2></FONT><BR></DIV>
<DIV><FONT face=Arial size=2>Hi Sebastien</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I've been using the GLU tesselator on mining
layouts - see attached picture. I have a filter vtkGLUTesselator filter
that extends the tesselator filter that is provided with hybrid. Holes,
concavity etc are not a problem. I can mail you source code and some demo
scripts if you like.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial
size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Malcolm Drummond</FONT></DIV>
<DIV><FONT face=Arial size=2>GeoVision cc</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=maraux@ondim.fr href="mailto:maraux@ondim.fr">Sebastien
MARAUX</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=vtkusers@public.kitware.com
href="mailto:vtkusers@public.kitware.com">vtkusers@public.kitware.com</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, March 13, 2003 4:23
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [vtkusers] (constrained)
delaunay2D issue</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Hello</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I am using Delaunay2D for triangulating
polygons </FONT></DIV>
<DIV><FONT face=Arial size=2>(representing dB levels around
airports).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I prefer this way to tesselate method as it
can deal with </FONT></DIV>
<DIV><FONT face=Arial size=2>holes.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For a special dB level, I can have several
polygons defining islands and holes (depending on polygon
orientation).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>So I set the polydata as input and as source,
so that holes are taken off the object.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. there is an issue using this method with
most of my </FONT></DIV>
<DIV><FONT face=Arial size=2>polygons : I can obtain "wrong" triangles
being holes instead </FONT></DIV>
<DIV><FONT face=Arial size=2>of filled (see enclosed) How can I fix it
?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>2. Is there other ways of dealing with holes,
based on </FONT></DIV>
<DIV><FONT face=Arial size=2>tesselate, which would be faster than
this delaunay </FONT></DIV>
<DIV><FONT face=Arial size=2>method?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thank you in advance</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Sebastien MARAUX</FONT></DIV>
<DIV><FONT face=Arial
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