[vtk-developers] Permission to replace vtkCellLocator with an improved version

[David Gobbi]

Yes, that's pretty much it.  I mean to rename vtkSurfacePicker to
vtkCellPicker, overwriting the existing vtkCellPicker and replacing
it.

   David


On Tue, Jan 19, 2010 at 11:04 AM, Will Schroeder
<will.schroeder at kitware.com> wrote:
> David, just to make sure, please elaborate on "replace vtkCellPicker with
> vtkSurfacePicker". I think you mean you'll replace the guts of vtkCellPicker
> with your vtkSurfacePicker functionality... is this correct?
>
> On Tue, Jan 19, 2010 at 12:21 PM, David Gobbi <david.gobbi at gmail.com> wrote:
>>
>> HI All,
>>
>> Around seven weeks ago I added a new class to VTK called
>> vtkVolumePicker  (http://www.vtk.org/Wiki/VTK/Volume_Picking) that
>> improved volume picking.  This class also included several
>> improvements for polydata picking that I needed for my applications,
>> including the ability to use a vtkCellLocator to speed up the pick.
>>
>> Soon after adding this class to VTK, I split off a subclass called
>> vtkSurfacePicker
>> (http://www.vtk.org/doc/nightly/html/classvtkSurfacePicker.html) that
>> has 95% of the functionality of vtkVolumePicker, but doesn't depend on
>> the VolumeRendering kit.  This vtkSurfacePicker is, essentially, an
>> improved vtkCellPicker.  Compared to vtkCellPicker, here is a summary
>> of the most important improvements:
>>
>> - the ability to add a vtkCellLocator to accelerate the picking of
>> large data sets (it's rather shocking that vtkCellPicker cannot do
>> this)
>>
>> - much faster algorithms for picking volumes and images.. the
>> vtkCellPicker does a tedious search through all the cells in the
>> vtkImageData, but this new picker simply intersects the view ray with
>> the image data
>>
>> - specifying an "opacity isovalue" value for more useful volume
>> picking, i.e. it doesn't pick transparent regions, instead it picks
>> the visible volume surface
>>
>> - several methods for getting more information about what was picked,
>> including IJK coords for images, volumes, and textures
>>
>> - it acknowledges the existence of mapper clipping planes... the
>> vtkCellPicker ignores clipping planes so it will pick regions that
>> have been clipped away
>>
>> I would like to replace the vtkCellPicker with this new
>> vtkSurfacePicker class.  Since it provides a superset of vtkCellPicker
>> functionality and improved performance, the change should be
>> transparent to all users.  The only problem might be conflicts between
>> the new methods and third-party subclasses of vtkCellPicker.
>>
>> Any thoughts?  Should I have sent this email to the ARB list instead?
>>
>>   David
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>
>
>
> --
> William J. Schroeder, PhD
> Kitware, Inc.
> 28 Corporate Drive
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