[vtkusers] Mesh Simplification

[Will Schroeder]

Hi Randall-

It sounds like you have quite a mess on your hands.

The simplest approach would be to use vtkQuadricClustering. It is fast and 
should handle the redundant triangles. It also allows you to handle the 
data in chunks using the StartAppend(), Append() and EndAppend() methods. 
This means you can read the data in pieces, and then add each piece one at 
a time until all the data is processed. You'll have to play with the 
binning to find one that produces reasonable results.

Will

At 02:52 PM 5/16/2005, Randall Hand wrote:
>I have a mesh that contains something on the order of ~1.5billion 
>triangles.  It's simply too large to manage, and frankly most of it is 
>redundant.  It's a map of a city, so it contains alot of co-planar 
>triangles that create walls of buildings or streets.  So ideally, I think, 
>I want a Decimation filter that combines triangles sharing an edge with 
>similar or equivalent normals.  Does such a filter exist?
>
>Also, can someone shed on light on how to do "streaming data" with 
>this?  Obviously, it's going to be difficult getting this all into memory 
>at once.  I'm currently using a vtkDataSetReader to read it in (VTK Legacy 
>Format), which takes approximately an hour & 8gig of RAM to read the 
>file.. (I've since switched to a vtkPolyDataReader, but haven't been able 
>to re-run it yet).
>
>--
>Randall Hand
>Visualization Scientist
>DOD ITL-ERDC, Vicksburg MS