[vtkusers] vtkAppendFilter with double precision points (UNCLASSIFIED)

[Dominik Szczerba]

Single precision is hard coded - and is so in many filters. I have long 
argued to let the user specify the type, but nobody seemed interested 
even in my patches.

My workaround is to maintain vtkAppendFilter2 (with an appropriate 
function to set the precision) under vtkmy structure.

Once again, if interest, I can contribute a few patches.

Dominik

Leiter, Kenneth (Cont, ARL/CISD) wrote:
> 
> 
> Classification:  * UNCLASSIFIED* **
> Caveats: NONE
>  
> 
> Hello all,
> 
> I am reading an exodus II file into vtk using the vtkExodusIIReader and 
> am converting the resulting vtkMultiBlockDataSet to a 
> vtkUnstructuredGrid for further processing.  I am using a 
> vtkAppendFilter to get from the vtkMultiBlockDataSet to a 
> vtkUnstructuredGrid.
> 
> However, I am losing precision for the point values after running 
> through the vtkAppendFilter.  I have verified that the points are double 
> precision before entering the filter and single precision afterwards.  I 
> am not surprised that I lose precision as it looks like a new vtkPoints 
> (default = single precision) is allocated in the vtkAppendFilter class 
> and there appears to be no way to change this behavior.
> 
> Does anyone have a workaround or another way to accomplish what I need 
> to do?  It was difficult enough to get the vtkExodusIIReader to read in 
> double precision points without converting them to floats!
> 
> Thanks,
> Ken
> 
> ---------------------------------------------------------
> Kenneth Leiter
> Scientific Visualization Team
> Lockheed Martin / ARL DoD Supercomputing Resource Center
> 
>  
> Classification:  * UNCLASSIFIED * **
> Caveats: NONE
> 
> 
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