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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=karthik.krishnan@kitware.com
href="mailto:karthik.krishnan@kitware.com">Karthik Krishnan</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=murat.aydin@netcad.com.tr
href="mailto:murat.aydin@netcad.com.tr">Murat Aydın</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Cc:</B> <A title=vtkusers@vtk.org
href="mailto:vtkusers@vtk.org">vtkusers@vtk.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, September 09, 2009 11:22
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [vtkusers] volume
calculation</DIV>
<DIV><BR></DIV>
<DIV class=gmail_quote>2009/9/9 Murat Aydın <SPAN dir=ltr><<A
href="mailto:murat.aydin@netcad.com.tr">murat.aydin@netcad.com.tr</A>></SPAN><BR>
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<DIV><FONT face=Arial size=2>Hi,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I am calculating volume of solid constructed by
vtkDelaunay3D applied to a point cloud.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>i am using vtkGeometryFilter ->
vtkTriangleFilter -> vtkMassProperties in order to get volume of the
solid.</FONT></DIV></DIV></BLOCKQUOTE>
<DIV><BR> </DIV>
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<DIV><FONT face=Arial size=2>I am not sure whether the calculated volume is
correct,</FONT></DIV></DIV></BLOCKQUOTE>
<DIV><BR>No issues AFAIK.<BR> <BR></DIV>
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<DIV><FONT face=Arial size=2>because if i add</FONT></DIV>
<DIV><FONT size=2><FONT face=Arial>vtkDecimatePro filter or
vtkSmoothPolyDataFilter the volume
changes.</FONT></FONT></DIV></DIV></BLOCKQUOTE>
<DIV><BR>It is certainly going to change a bit. The locations of the points
comprising the polydata are going to change due to smoothing and this is going
to impact the projected volume.<BR> </DIV>
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<DIV><FONT size=2><FONT face=Arial>Without vtkDecimatePro , the volume seems
to be more than it should be.What should i do to find true volume? Thanks in
advance.</FONT></FONT></DIV></DIV></BLOCKQUOTE>
<DIV><BR>How do you arrive at that conclusion. Please take a look at the paper
referenced in the header.</DIV><FONT color=#ff0000></FONT>
<DIV><BR><FONT face=Arial color=#ff0000 size=2>I am comparing my results with
a software called Surpac. I am assuming Surpac is correct because it is a well
known software in mining industry.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT><BR>At most there may be numerical issues
with computing the projected volume of axis aligned triangles. The filter
alleviates this by computing the volume along the three axes and averaging
them. <BR><BR></DIV></DIV>
<DIV><BR clear=all><BR>-- <BR>karthik</DIV>
<DIV><FONT color=#ff0000></FONT> </DIV>
<DIV><FONT color=#ff0000>I am sure vtkMassProperties is working correctly. My
problem is that i am not sure whether vtkDelaunay3D represents my solid
correctly. If so, volume will be correct. How can i make vtkDelaunay3D
to represent my solid correctly? How can i remove unneccessary triangles? Or
should i use vtkLinearSubdivisionFilter to increase number of triangles? I am
new to vtk, so please give me some advise.</FONT></DIV>
<DIV><FONT color=#ff0000>In some cases i have less number of points in point
cloud, and in some cases i have many points in point
cloud.</FONT></DIV></BLOCKQUOTE></BODY></HTML>