<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2900.2668" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV>Hi Joseph,</DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2><FONT face="Times New Roman" size=3>Thanks for your
suggestion that I should build cells and links on my Polydata</FONT>.<FONT
face="Times New Roman"><FONT size=3> I implemented the method you suggested and
got non zero values for the curvature. I assumed that the vtkObjReader class
generated Polydata with the cells and links built. I just found out from
previous archives that the ObjReader has a bug in it that causes the
problem.</FONT></FONT></FONT></DIV>
<DIV><FONT face=Arial size=2><FONT face="Times New Roman"><FONT face=Arial
size=2></FONT></FONT> </DIV></FONT>
<DIV>"vtkOBJReader duplicates (and triplicates!...) vertex geometry. This
is<BR>because is reads a face from file, then gets the vertices of the face
which<BR>it inserts into a vtkPoints object. Since faces share vertices (in a
mesh)<BR>with one another they get duplicated."</DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><A
href="http://public.kitware.com/pipermail/vtkusers/2001-June/056403.html">http://public.kitware.com/pipermail/vtkusers/2001-June/056403.html</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>I adopted the fix suggested in the above mail and it gave me similar
results to the ones you got. </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>Just one more query. Has anyone tried to implement the Dorai and
Jain shape index formula for finding landmarks using Principal curvature
values? I just wanted to know if the expected values for the shape index
were obtained using the curvature values calculated from the
vtkCurvature class. </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>Cheers,</DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>Prathap Nair</DIV></BODY></HTML>