[vtk-developers] vtkImageDataGemoetryFilter tweaks and other questions

[John Biddiscombe]

If you have some (eg terrain) data and you want convert it to polygons, warp
it and visualize it as 3D terrain (and if the data has a lot of blank ocean
with zero height) you might do this...

vtkImageData->vtkThreshold->vtkGeometryFilter->vtkTriangleFilter->vtkWarpScalar

the trouble is that you might have a lot of temporary unwanted memory
consumption because of the conversion to unstructured grid then polys
when many cells will not be used

I've added a couple of options to vtkImageDataGeometryFilter so that you can
SetThresholdCells(1); // boolean
SetThresholdValue(5.0); // double
SetOutputTriangles(1); // boolean

so it becomes
vtkImageData->vtkWarpScalar
and significantly less intermediate memory is used. But these options only 
take
effect when using 2D image data (documented) - not 3D volume or 1D line.

I'd like to commit this as it's surely a useful addition, but do I just
commit stuff like this in future or should I consult anyone first. I'm
worried that I have many tweaks to vtk code that are a bit specialized and
maybe shouldn't be included.

Also, what's the policy with regard to the bug tracker. It's been around a 
while now, and seems to be being used more and more, but those of us non 
kitware people who make commits have not had any word about when we need to 
use it etc. Is this primarily for Kitware's peace of mind and management 
(and perhaps those people who are creating FDA approved software) or should 
we all adopt the policy that cvs commits should always be accompanied by a 
bug/feature reference etc unless its something quite trivial. For something 
like the above addition - do I need to create a feature request, then commit 
stuff against it?

JB