[vtkusers] vtkPolydata usage in refinment algorithm

Will Schroeder will.schroeder at kitware.com
Wed Sep 18 06:29:02 EDT 2002


Hi Sagi-

If you want to do stuff like this I recommend that you study vtkDecimate 
and vtkDecimatePro for efficient local operation on vtkPolyData.

Will

At 11:21 AM 9/18/2002 +0200, sagi schein wrote:

>I am running into problems when using vtkPolyData in the following manner.
>
>1. There is an initial stage where I read points / cells and build a poly mash
>
>2. In a later stage I need to add points and update cell structure 
>accordingly. The algorithm basically takes a cell, and according to some 
>criterion decides to split it. It then generates a new point and creates 
>two triangles from the single triangle it had earlier.
>
>3. At start I added points and using InsertNextCells() to add new cells 
>and ReplaceCell() to change old one. It did not work until I added a 
>DeleteLinks() call and then BuildLinks(). After that everything went ok 
>but for all practical sized mashes it takes too much. The bottle neck lies 
>in the call for DeleteLinks().
>
>4. After that I tried to use ReplaceLinkedCell and InsertNextLinkCell() 
>but got memory assertions and was not successful in getting this to work.
>
>
>
>My basic problem is that I need the ability to make topological queries on 
>the altered mesh since the algorithm needs to consider cells that were 
>splitted as well, So I have to make GetCell() calls on the structure.
>
>
>
>If anyone has any experience with such a scenario I could use some help
>
>Thanks
>
>Sagi Schein
>
>
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