CGAL users discussion list

[郑银河 <>]

Thank you for the reminder @ Benjamin
I have noticed that Tetgen uses the exact predicates. And I have tried
to switch the default Shewchuk's predicates to CGAL's kernel.
However, the Tetgen package is still using floating-point airthmetic
and represent the coordinates of points using "double". The Steiner
points are constructed inexactly using floating point numbers. I am
trying to find a package that can construct Steiner points in an exact
form.

Anyway, thanks for your kind reminder.
ps: Acturally, switching the predicate kernel in CGAL is pretty easy
but I don't think that is necessary, because the default adaptive
exact predicates works pretty well.

Best
Yinhe


2015-10-29 13:05 GMT-07:00 Benjamin Kehlet 
<>:
> On 29 October 2015 at 17:45, 郑银河 
> <>
>  wrote:
>>
>> Thank you for the reminder @ Olivier Devillers.
>> I find a package called Tetgen on the web, which can generate the CDT
>> by adding extra points.
>> However, that package is implemented using float point number
>> arithmetic. I am trying to reimplement that package using the exact
>> arithmetic interface provided in CGAL
>
>
> Just in case you have overlooked it: Tetgen uses robust predicates. By
> default it is Shewchuk's predicates, but it can also use CGAL's EPICK
> kernel. See
> http://wias-berlin.de/software/tetgen/1.5/doc/manual/manual004.html#sec25
> The relevant section is 3.1.4.
> (Note that I haven't tried this myself)
>
> Best regards
>
> Benjamin Kehlet
>
>
>>
>> 2015-10-29 1:11 GMT-07:00 Olivier Devillers 
>> <>:
>> >
>> >
>> > Le 29/10/15 04:17, 郑银河 a écrit :
>> >
>> > Thanks for your kind replies.
>> > Finally, I am planning to implement this feature by my self to solve my
>> > problem.
>> >
>> >
>> > A constrained DT does not always exist in 3D
>> > (there exists polyhedra that cannot be triangulated using the prescribed
>> > edges (or faces)
>> > without adding new vertices [ Schönhardt polyhedron] ).
>> >
>> >
>>
>> --
>> You are currently subscribed to cgal-discuss.
>> To unsubscribe or access the archives, go to
>> https://sympa.inria.fr/sympa/info/cgal-discuss
>>
>>
>