[vtk-developers] Memory issues : vtkDataSetSurfaceFilter in PV

[John Biddiscombe]

When generating a multi-block dataset of about 4million cells (hex/tet), 
I have no trouble, but when paraview tries to run its 
vtkPVGeometryFilter in turn using vtkDataSetSurfaceFilter, I've got 
problems.

I notice that
a) It could be possible to switch out vtkDataSetSurfaceFilter and put in 
vtkGeometryFilter inside vtkPVGeometryFilter, this would save some memory
b) The vtkDataSetSurfaceFilter wants to create new vertex arrays for all 
inputs. Is this really necessary, the surface extracted is always a 
subset of the input (true?) - why not shallow copy points from in->out 
instead of allocating lots.

I am considering wading into b) and redoing part of 
vtkDataSetSurfaceFilter, but this filter really is a 'bad boy' and I'm 
not sure I want to take on such a big job right now.

In particular, my 7 blocks are read from the same file, they share 
points so there is only one copy. When passed through the surface 
filter, each set of points gets newly created - then when put into the 
append filter prior to rendering, they get copied again. I'd like to 
shallow copy them through the surface filter, then modify 
vtkAppendPolyData so that if all inputs are reference counting the same 
points, it will reuse them

Any comments or suggestions anyone?

JB

-- 
John Biddiscombe,                            email:biddisco @ cscs.ch
http://www.cscs.ch/about/BJohn.php
CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.07
Via Cantonale, 6928 Manno, Switzerland      | Fax:  +41 (91) 610.82.82