[vtkusers] REG: best method for closest point search

[Gerald Dalley]

I have been doing some work with 3d registration and created a partial
implementation of a kD tree locator.  I've implemented BuildLocator and
FindClosestPoint.

FYI, if you modify the source a little for the existing locator classes, you
can actually get them to work for these purposes.  The key it to allow
detection of closest points when the search point is outside the bounding
box of the data points.  It's not as fast as a kD tree in general, but it
works.

I'm including the locator files as an attachment.

--Gerald Dalley
  dalleyg at dma.org


-----Original Message-----
From: vtkusers-admin at public.kitware.com
[mailto:vtkusers-admin at public.kitware.com]On Behalf Of Will Schroeder
Sent: Friday, 18 May 2001 9:11 AM
To: Kiran, P (CORP, GEITC); vtkusers at public.kitware.com
Cc: Sebastien BARRE; dalleyg at dma.org
Subject: Re: [vtkusers] REG: best method for closest point search


Hi Kiran-

There is no k-d tree implementation that I know of. This would be a very
nice addition to vtk. An adaptive spatial structure would be very helpful in
situations where there is large variation in point density, e.g., an
unstructured grid that is refined in a boundary layer. Operations like
contouring would be sped up considerably (it uses vtkMergePoints). In the
past I've had to resort to creating point locators with large dimensions
(500^3) and this takes way too much memory.

Will


At 04:11 PM 5/18/2001 +0530, Kiran, P (CORP, GEITC) wrote:
>Hi VTK gurus,
>
>I am doing 3-D image registration work. Right now, I am using the some
>built-in locators to find the closest point of one surface to the other.
>Has anyone implemented  a FindClosestPoint method that uses kd trees in
VTK?
>Are there  any best methods techniques for finding the closest point?
>Thanks in advance for help.
>Kiran


William J. Schroeder, Ph.D.
Kitware, Inc.
469 Clifton Corporate Parkway
Clifton Park, NY 12065
will.schroeder at kitware.com
1-518-371-3971 x102 (phone)
1-518-371-3971 (fax)


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