[vtkusers] Sub-sampling a point cloud

[Goodwin Lawlor]

Or just generate vertex cells (if you dont already have them) with the 
vtkMaskPoint class and the GenerateVerticesOn method. If you want to 
visualize all the points then "mask->SetOnRatio(1);"

Goodwin Lawlor wrote:
> 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
>