[vtkusers] 3d shape complexity

[John Smith]

Hi Bryn,

Thanks for your advice, All my shapes are oriented so vtkMassProperties works fine for closed surfaces (as you mentioned). However, do you have any suggestions for open surfaces (like cortical surface for example)?

Many thanks,

John 


________________________________
From: Bryn Lloyd <lloyd at itis.ethz.ch>
To: 'John Smith' <af3113 at yahoo.com>; 'vtk' <vtkusers at vtk.org>
Sent: Friday, October 21, 2011 1:58 AM
Subject: RE: [vtkusers] 3d shape complexity


Hi John
 
It would be useful to know how your shape is represented.
Is it a surface? Is it closed?
 
Assuming it is a surface (and orientable / closed):
 
1.       You could maybe use the curvature filter (vtkCurvatures).
 
2.       Also, using vtkMassProperties you can compute mass, volume, area and a socalled surface index…
According to the docs:
“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.”
 
Good luck
Bryn
 
 
 
 
 
 
 
From:vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] On Behalf Of John Smith
Sent: Friday, October 21, 2011 3:17 AM
To: vtk
Subject: [vtkusers] 3d shape complexity
 
 
Dear all,
 
Is there a class/function in VTK to measure 3d shape complexity? Your feedback and suggestions are really appreciated.
 
Thanks,
 
John
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