CGAL users discussion list

["daiycheng" <>]

ANN is a library written in the C++ programming language to support both

exact and approximate nearest neighbor searching in spaces of various

dimensions.  It was implemented by David M. Mount of the University of

Maryland, and Sunil Arya of the Hong Kong University of Science and

Technology.  ANN (pronounced like the name ``Ann'') stands for

Approximate Nearest Neighbors.  ANN is also a testbed containing

programs and procedures for generating data sets, collecting and

analyzing statistics on the performance of nearest neighbor algorithms

and data structures, and visualizing the geometric structure of these

data structures.

The ANN source code and documentation is available from the following

web page:

    http://www.cs.umd.edu/~mount/ANN

For more information on ANN and its use, see the ``ANN Programming

Manual,'' which is provided with the software distribution.

 

 

2009-12-27

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daiycheng

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发件人： Zheng,Guang

发送时间： 2009-12-27  01:06:46

收件人： cgal-discuss

抄送：

主题： Re: [cgal-discuss] normal vector for large point data

could you tell me a little bit more about ANN?

2009/12/26 杨成林 <>

The spatial searching package in CGAL is not very efficient. Maybe you should consider ANN.

2009/12/26 lhc_liuyu <>

The method to compute the normal vector of each vertex in a any size point cloud data can be found in journal of CAGD; I forget the title of the paper;the details of the method is: find a surface(paraboloid,such as) to fit the vertices in neigbor field (a given radius),and the normal of the a surface can be considered  as the normal of vertex.  

在2009-12-25，"Zheng,Guang" <> 写道：

Hi,

Has anyone compute the normal vector for a large size point cloud data (more than 10M), it seems that the algorithm provided by CGAL is not so efficient for this kind of size dataset. Anyone has any suggestions about this? 

Right now, my computer has been running more than 10 hours (8CPU and 4G RAM, windows 64bit). 

Thanks very much!

--
Guang

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杨成林
Yang Chenglin

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Guang Zheng