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["" <>]

Thank you very much！ I had reliazed that after the email was sent. 

    Now l’m trying to generate a finer triangularation. The current triangularaton seems to be containing the given vertices only.

     Could l have a finer delauny triangulation of a dD-Box, just by these given vertices？

      By the way.  lm new to CGAL. My problem involves dD delauny points. But i found that the user guide of CGAL is really difficult to read.(≧∇≦)/

               Best regard

      Liu

发自我的荣耀手机

-------- 原始邮件 --------
发件人： Marc Glisse <>
日期： 2024年3月8日周五 17:50
收件人：
主 题： Re: [cgal-discuss] FW: The dD-Triangulation seems to be incorrect,
CGAL version 5.6.1

On Fri, 8 Mar 2024, CGAL_problem  wrote:

> My codes are as follows :

Please always provide a complete testcase, with #include and function, to
make it easier for us to reproduce the issue (and preferably as an
attachment or a github gist because some email programs do unspeakable
things to the main text).

> 2. why the order of input finite vertices are changed?

CGAL first sorts the points according to some particular order (though in
Triangulation_3 that's only done for Delaunay and not for a plain
triangulation).

Points are then stored in a triangulation where they don't have any order.
What you get is the order in which a graph traversal happens to visit
those vertices.

If you want to remember information about vertices (say an int
corresponding to their initial index), the doc has information about how
to achieve that.

> 3. The expected results would contain the following tetrahedra, but I can not find them in the output file.

There are several possible triangulations, there is no reason to expect
one in particular.

>>>>> The results in the output file are as follows:   
> 3
> 8
> 3 1 2 -3
> 3 1 -2 -3
> 3 -1 -2 -3
> 3 1 2 3
> 3 -1 2 -3
> 3 1 -2 3
> 3 -1 -2 3
> 3 -1 2 3
> 3 1 2 -3

Notice that it announces 8 points and then proceeds to print 9. My guess
is that one (the first) is the infinite vertex, which does not have a
point associated to it, so the coordinates it prints are read from a
random place in memory (happens to be the point of another vertex here).
Maybe we could improve that in CGAL, I didn't check what Triangulation_3
does.

Does that help interpret the output you get?

--
Marc Glisse

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