[vtkusers] Sub-sampling a point cloud

[Goodwin Lawlor]

Hi Sarah,

John Biddiscombe has a point sprite mapper for rendering large amounts 
of point data. vtkPointSpriteMapper: 
http://www.cscs.ch/index.php?option=com_content&task=view&id=97&Itemid=134

You could try vtkSurfaceReconstructionFilter to create a surface from 
your points. If it doesn't work out you could try Tim Hutton's port of 
the powercrust algorithm (a more robust algorithm than 
vtkSurfaceReconstructionFilter): http://www.sq3.org.uk/powercrust/

hth

Goodwin

Sarah Macumber wrote:
> 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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>>
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