CGAL users discussion list

[杨宝容 <>]

Hi, everyone. Is there any one who has ever used the OpenCSG library, i have some problems like this compiling:

displaylistPrimitive.obj : error LNK2019: unresolved external symbol "public: __thiscall OpenCSG::Primitive::Primitive(enum OpenCSG::Operation,unsigned int)" (??0Primitive@OpenCSG@@QAE@W4Operation@1@I@Z) referenced in function "public: __thiscall OpenCSG::DisplayListPrimitive::DisplayListPrimitive(unsigned int,enum OpenCSG::Operation,unsigned int)" (??0DisplayListPrimitive@OpenCSG@@QAE@IW4Operation@1@I@Z)

displaylistPrimitive.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall OpenCSG::Primitive::~Primitive(void)" (??1Primitive@OpenCSG@@UAE@XZ) referenced in function "public: virtual __thiscall OpenCSG::DisplayListPrimitive::~DisplayListPrimitive(void)" (??1DisplayListPrimitive@OpenCSG@@UAE@XZ)

i have tried to change the project properties but it still doesn't work, can you tell me why and how to fix it? thank you!

Monica

-----原始邮件-----
发件人: "Jane Tournois" <>
发送时间: 2014-10-14 15:55:33 (星期二)
收件人:
抄送:
主题: Re: [cgal-discuss] Mesh_3: Problem with isolated vertices

Hi Benjamin,

Le 13/10/2014 20:01, Benjamin Kehlet a écrit :

Hi Jane

2014-10-13 17:25 GMT+02:00 Jane Tournois <>:

Hi Benjamin,

you are not doing anything wrong.

As you have noticed, the mesh itself is the C3T3
(Complex_3_in_triangulation_3).
The C3T3 is a subset of the triangulation.
So, there can be cells, and vertices, that belong to the triangulation, but
not to the C3T3.

In your particular example, the criteria that you are using to generate the
mesh are a bit too weak. One symptom of that is that the surface is not very
well fitted by the mesh. You can see it if you output the mesh to Medit for
example.

About isolated vertices, it's the same as for cells. It is not forbidden to
have one or several vertices that belong to the triangulation but not to the
triangulation.
It can be the case for example when a vertex is first inserted on the
boundary (let's say during the initialization step), but then the refinement
process changes the connectivity around it, and the vertex can start not to
belong to the boundary anymore.

Ah! I didn't know that could happen.

To make it short :
- it is not a bug
- the object that are interested in at the end/during the mesh generation
process is the C3T3

Thanks a lot for the explanation, Jane! That was very enlightening.

So just to be sure: It is then my responsibility to grab only the
relevant vertices from the triangulation, right? (Since the C3T3 does
not provide an iterator over the vertices that belong to the complex.)

Yes, you are right.

You can iterate on cells, using the Cells_in_complex_iterator
(see http://doc.cgal.org/latest/Mesh_3/classMeshComplex__3InTriangulation__3.html )
and then collect the vertices.

The iterator on vertices that you can use on a C3T3 is Vertices_in_complex_iterator
(see http://doc.cgal.org/latest/Mesh_3/classMeshComplexWithFeatures__3InTriangulation__3.html )
but it iterates only on the corners of the object.

Regards,
Jane.

Regards

Benjamin

Best regards,

Jane.


--
Jane Tournois, PhD
R&D Engineer at GeometryFactory
http://www.geometryfactory.com/



Le 13/10/2014 10:41, Benjamin Kehlet a écrit :

2014-10-13 9:55 GMT+02:00 Clément Jamin <>:

Hi Benjamin,

Do you use the *parallel* mesh algorithm that is available in CGAL 4.5
(with CGAL::Parallel_tag)?

Hello Clément!

No, this is in serial.

Regards

Benjamin

Best,
Clément.


On Mon, Oct 13, 2014 at 12:44 AM, Benjamin Kehlet <>
wrote:

Hello CGAL community!

When meshing polyhedral domains, I sometimes experience isolated
vertices, ie. vertices which does not belong to any cell. The attached
file demonstrates the problem. Could someone take a look, and check if
I'm doing anything wrong? The code for reading out the mesh is based
on the code in CGAL for exporting to medit's file format.

I get this result when attempting to mesh the file
demo/Polyhedron/data/rotor.off from CGAL's source tree:

benjamik@benjamik-ThinkPad:~/tmp/cgal-meshing/build$ ./main
~/software/CGAL-4.5/demo/Polyhedron/data/rotor.off

[...]

Number of unconnected vertices:14
0.0693619 0.340288 -0.260398 0
0.148692 0.344385 -0.252795 0
0.11059 0.332426 -0.267569 0
0.0800736 0.308173 -0.290017 0
0.0358875 0.312982 -0.283919 0
0.0739249 0.2902 -0.306196 0
0.100469 0.304801 -0.293518 0
0.0949104 0.318775 -0.276573 0
0.0777684 0.350724 -0.248457 0
0.0909964 0.338994 -0.261008 0
0.0263695 0.298269 -0.299189 0
0.00269295 0.307881 -0.290388 0
0.0496229 0.300013 -0.297675 0
-0.0248875 0.311644 -0.285615 0

Also a few other files (at least cow.off and bones.off and maybe
others) in the same directory reproduces the problem.

Best regards

Benjamin Kehlet

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-- 
Jane Tournois, PhD
R&D Engineer at GeometryFactory
http://www.geometryfactory.com/