[vtkusers] Sub-sampling a point cloud

[Sarah Macumber]

I did Amy & it works great to subsample my large data sets, I still have
trouble visualizing as many points as I actually do have (10 million).
Any suggestions for how to visualize lots and lots of data in a point
cloud?  Also when I try to use Marching Cubes or Delauny to get polygon
info from my point cloud it doesn't look so great, am I missing
something, do I need a cell set?

Thanks Sarah

-----Original Message-----
From: Amy Squillacote [mailto:ahs at cfdrc.com] 
Sent: Friday, April 25, 2008 6:45 AM
To: Sarah Macumber
Cc: vtkusers at vtk.org
Subject: Re: [vtkusers] Sub-sampling a point cloud

Have you tried vtkMaskPoints? This will work if you are using a point 
cloud (i.e., vertices only, no triangles, quads, etc.). If you do have 
geometry (triangles, quads, ...), there are a few decimation algorithms 
in VTK you could try: vtkDecimatePro, vtkQuadricClustering, ... (Look at

the on-line documentation for others.)

- Amy

Sarah Macumber wrote:
> -->
>
> Hi, does anyone know what a good way to sub-sample or down sample a 
> point cloud of data would be?  As in, if you had a million points 
> representing a 3D object like a  cylinder how could you sub-sample 
> that data so you only had a thousand points which still represented 
> the geometry but coarsely?
>
>  
>
> Thanks in advance, Sarah
>
>  
>
> *************************************************************
>
> Sarah Macumber, Engineer
>
>  
>
> Quest Reliability, LLC
>
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>
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-- 
Amy Squillacote                    Phone: (256) 726-4839
Computer Scientist                 Fax: (256) 726-4806
CFD Research Corporation           Web: http://www.cfdrc.com
215 Wynn Drive, Suite 501
Huntsville, AL  35805