[Paraview-developers] Re: [vtk-developers] A PT mapper for VTK

[Ken Martin]

> > 1) The sorting classes sound like they do something similar
> > to the existing polydata cell sorting class that already
> > exists. vtkDepthSort or something like that. How do these
> > classes relate to that class?
> 
> I assume you mean vtkDepthSortPolyData.  Yes, I originally looked into
> using that, but quickly ruled it out.    vtkVisiblitySort and its
> subclasses need to resort on a per-frame basis.  

I believe DepthSortPolyData also does this on a per frame basis. Am I
confused? (about this specific issue, not in general)

> vtkDepthSortPolyData,
> which of course is a filter, needs to build a new vtkDataSet and copy a
> bunch of attributes every time.  vtkVisibilitySort, in contrast, just
> returns a list of sorted cell ids, thereby minimizing the memory
> shuffling.
> 
> > Can they be combined?
> 
> Yes.  vtkDepthSortPolyData can use a vtkVisibilitySort to get a sorted
> list of cell ids, then build its output based on that.

Can you please make this change?

> > 2) vtkSort is a very generic name. If it is designed to sort
> > data arrays then can we call it vtkSortDataArray ? If it is
> > more generic then I would look at it from the other point of
> > view, what does it not sort?
> 
> vtkSort specifically sorts only vtkDataArray and vtkIdArray.  I have no
> problem changing the name to vtkSortDataArray or the like.

Let's call it vtkSortDataArray
 
Thanks
Ken