<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>Hi Bryn,</div><div><br></div><div>Thanks for your advice, All my shapes are oriented so <span class="Apple-style-span" style="color: rgb(31, 73, 125); font-family: sans-serif; font-size: 15px; ">vtkMassProperties works fine for closed surfaces (as you mentioned). However, do you have any suggestions for open surfaces (like cortical surface for example)?</span></div><div><span class="Apple-style-span" style="color: rgb(31, 73, 125); font-family: sans-serif; font-size: 15px; "><br></span></div><div><span class="Apple-style-span" style="color: rgb(31, 73, 125); font-family: sans-serif; font-size: 15px; ">Many thanks,</span></div><div><span class="Apple-style-span" style="color: rgb(31, 73, 125); font-family: sans-serif; font-size: 15px; "><br></span></div><div><span class="Apple-style-span" style="color: rgb(31, 73, 125);
font-family: sans-serif; font-size: 15px; ">John </span></div><div><br></div><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "><font size="2" face="Arial"><hr size="1"><b><span style="font-weight:bold;">From:</span></b> Bryn Lloyd <lloyd@itis.ethz.ch><br><b><span style="font-weight: bold;">To:</span></b> 'John Smith' <af3113@yahoo.com>; 'vtk' <vtkusers@vtk.org><br><b><span style="font-weight: bold;">Sent:</span></b> Friday, October 21, 2011 1:58 AM<br><b><span style="font-weight: bold;">Subject:</span></b> RE: [vtkusers] 3d shape complexity<br></font><br>
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--></style><div><div class="yiv6994632WordSection1"><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">Hi John</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">It would be useful to know how your shape is represented.</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">Is it a surface? Is it closed?</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">Assuming it is a surface (and orientable /
closed):</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoListParagraph" style=""><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "><span style="">1.<span style="font:7.0pt "Times New Roman";"> </span></span></span><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">You could maybe use the curvature filter (vtkCurvatures).</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoListParagraph" style=""><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "><span style="">2.<span style="font:7.0pt "Times New Roman";">
</span></span></span><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">Also, using vtkMassProperties you can compute mass, volume, area and a socalled surface index…</span></div><div class="yiv6994632MsoNormal" style="text-indent:.5in;"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">According to the docs:</span></div><div class="yiv6994632MsoNormal" style="text-indent:.5in;"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">“Compute and return the normalized shape index. This characterizes the deviation of the shape of an object from a sphere. A sphere's NSI is one. This number is always >= 1.0.”</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family:
sans-serif; ">Good luck</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">Bryn</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; ">
</span></div><div class="yiv6994632MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125); font-family: sans-serif; "> </span></div><div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt;"><div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in;"><div class="yiv6994632MsoNormal"><b><span style="font-size: 10pt; font-family: sans-serif; ">From:</span></b><span style="font-size: 10pt; font-family: sans-serif; "> vtkusers-bounces@vtk.org [mailto:vtkusers-bounces@vtk.org] <b>On Behalf Of </b>John Smith<br><b>Sent:</b> Friday, October 21, 2011 3:17 AM<br><b>To:</b> vtk<br><b>Subject:</b> [vtkusers] 3d shape complexity</span></div></div></div><div class="yiv6994632MsoNormal"> </div><div><div><div class="yiv6994632MsoNormal" style="background:white;"><span style="color:black;"> </span></div></div><div><div><div class="yiv6994632MsoNormal" style="background:white;"><span
style="color:black;">Dear all,</span></div></div><div><div class="yiv6994632MsoNormal" style="background:white;"><span style="color:black;"> </span></div></div><div><div class="yiv6994632MsoNormal" style="background:white;"><span style="color:black;">Is there a class/function in VTK to measure 3d shape complexity? Your feedback and suggestions are really appreciated.</span></div></div><div><div class="yiv6994632MsoNormal" style="background:white;"><span style="color:black;"> </span></div></div><div><div class="yiv6994632MsoNormal" style="background:white;"><span style="color:black;">Thanks,</span></div></div><div><div class="yiv6994632MsoNormal" style="background:white;"><span style="color:black;"> </span></div></div><div><div class="yiv6994632MsoNormal" style="background:white;"><span style="color:black;">John</span></div></div></div></div></div></div></div></div><br><br></div></div></div></body></html>