[vtkusers] 3D point cloud nearest neighbor search

[G. Allegri]

Thanks David, I will give it a try and I'll let you know.

2010/10/12 David Doria <daviddoria at gmail.com>:
> On Tue, Oct 12, 2010 at 4:23 AM, G. Allegri <giohappy at gmail.com> wrote:
>> Hello. I'm new to VTK and this list, so forgive my trivial questions.
>>
>> I'm considering to use VTK to solve a conceptually simple problem, but
>> that require efficient 3D algorithms and data structures. I have a csv
>> file which represents a 3D grid of points (SET1). In this specific
>> case their regularly spaced on the three axes, but the general case
>> can be an irregular point cloud. The dataset is made of a couple of
>> millions of points. I also have another set of 3D points (SET2). I
>> need to set attributes in SET2 "sampling" the NN from SET1.
>>
>> I've chosen VTK having seen the various kd-tree and locator classes,
>> but I wonder what is the most efficient way to achieve my goal, and
>> what data structured is best for this. I'm considering vtkPolyData or
>> vtkUnstructuredGrid. What would you suggest for my datas and problem?
>> Are there efficient classes to read csv input streams to fill my data
>> structures?
>>
>> Thanks a lot,
>> Giovanni
>
> You can modify this to read your csv file into a vtkPolyData:
> http://www.vtk.org/Wiki/VTK/Examples/Cxx/InfoVis/ReadDelimitedFile
>
> Then build a vtkKdTreePointLocator to do the NN queries:
> http://www.vtk.org/Wiki/VTK/Examples/Cxx/DataStructures/KdTreePointLocator/ClosestPoint
>
> Let us know if you have any trouble once you give it a shot.
>
> David
>