CGAL users discussion list

[王进 <>]

Hi Mr. Moeller,

Thanks for your answers. Regarding the three problems you mentioned, 
"duplicated vertices" are well understood. However, the other two are 
not as clear. Could you please define and/or further explain what are 
"self-intersections and some faces seem to be oriented the wrong way 
around"? If possible, please also provide some examples.

Greatly appreciate your help.

Wang Jin

At 2012-03-20 20:52:10,"Philipp Moeller" <> wrote:
>OK, I could reproduce the problem. What sticks out are the duplicated
>vertices, self-intersections and some faces seem to be oriented the
>wrong way around. You should try to fix those first, otherwise it is
>unlikely that mesh simplification will give you the results you want.
>
>All of this shouldn't make it crash but it is a good start.
>
>
>HTH,
>Philipp Moeller
>GeometryFactory
>
>
>王进 <> writes:
>
>> Hi,Philipp Moeller
>> you are right,Simple_cartesian quite faster than Cartesian,but crashed yet
>> I provide a piece of test data and code in attachment,please tell me the problem and give me some suggestions.
>> thanks very much.
>> WangJin
>>
>> 在 2012-03-18 21:21:02，"Philipp Moeller" <> 写道：
>>>王进 <> writes:
>>>
>>>> Hi,CGAL Developers:
>>>> I use Lindstrom-Turk edge-collapse algorithm for mesh simplification,but CGALcrashed at Handle_for.h  
>>>>
>>>> bool
>>>> is_shared() const
>>>>    {
>>>>         return ptr_->count > 1;   
>>>>     }
>>>>
>>>> because of ptr_ is invalid pointer.
>>>> the call stack show as below
>>>>
>>>> CGAL::Surface_mesh_simplification::EdgeCollapse
>>>> ->boost::put
>>>> ->CGAL::Point_3<CGAL::Cartesian<double> >::operator=
>>>> ->CGAL::PointC3<CGAL::Cartesian<double> >::operator=
>>>> ->CGAL::Vector_3<CGAL::Cartesian<double> >::operator=
>>>> ->CGAL::VectorC3<CGAL::Cartesian<double> >::operator=
>>>> ->CGAL::Handle_for<boost::array<double,3>,std::allocator<boost::array<double,3> > >::operator=
>>>> ->CGAL::Handle_for<boost::array<double,3>,std::allocator<boost::array<double,3> > >::~Handle_for
>>>> ->CGAL::Handle_for<boost::array<double,3>,std::allocator<boost::array<double,3> > >::is_shared() <---crashed
>>>>
>>>> for help!
>>>>
>>>> Wang 
>>>
>>>A hint first: Don't use Cartesian<double>, performance is probably going
>>>to be a lot better with Simple_cartesian<double>. Simple always means
>>>better, right? ;)
>>>
>>>Can you provide a complete, minimal test-case that shows the problem? I
>>>have used Mesh simplification extensively throughout last week and
>>>nothing blew up in my face, but then again I was using Simple_cartesian.
>>>
>>>Cheers,
>>>Philipp Moeller
>>>GeometryFactory
>>>
>
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