CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 02/10/2017 03:46 PM, Iván otero wrote:
> Hi Sebastien!
>
> Thank you for your help.
>
> I have now this.
>
> Plane_3suelo(Point_3(0,0,0),Vector_3(0,0,-1));//Suelo
>
> Plane_3principal(Point_3(0,0,0),Vector_3(0,1,0));//Principal
>
> Plane_3lateral3(Point_3(0,5,0),Vector_3(-1,0,0));//Lateral3
>
>
> boost::optional<boost::variant<Point_3,Line_3,Plane_3>>res=CGAL::intersection(suelo,principal,lateral3);
>
>
> if(res!=boost::none)
>
> {
>
> if(constPlane_3*pl=boost::get<Plane_3>(&(*res)))
>
> {
>
>
> }
>
> elseif(constLine_3*l=boost::get<Line_3>(&(*res)))
>
> {
>
>
> assert(l!=NULL);
>
> }
>
> elseif(constPoint_3*p=boost::get<Point_3>(&(*res)))
>
> {
>
>
> std::cout<<"elpuntoes:"<<p<<std::endl;
>
>
> }
>
>
> }
>
>
> *What do you think about store this points an after access to this
> structure?*
> *
> *
> *In my case I want to iterate with all surface of one space and get this
> points.*
> *
> *
> Some other beginner question.
>
>     How to show or view values of vector and plane?

You can access the plane coefficients, see
http://doc.cgal.org/latest/Kernel_23/classCGAL_1_1Plane__3.html



>     I use debugger of Qt and try to view this information but I cant see
> them like you can see in this image (view cgal_001.png)
>
>     But p i can't see it.

p is a pointer, so you need to print *p.


Sebastien.

>     Could you help me?
>
> *
> *
> *Thanks and best regards.*
>
> 2017-02-10 8:05 GMT+01:00 Sebastien Loriot (GeometryFactory)
> <
>  
> <mailto:>>:
>
>     On 02/09/2017 05:26 PM, Iván otero wrote:
>
>
>         Could you recomend any post link about cgal and about how to
>         calculate
>         intersection of 3 planes.
>         In my case I have normal vector of plane and centroide.
>
>         I need to know the know how of cgal to calculate this point
>         I know mathematics to calculate it but I would like to get this
>         point
>         with cgal.
>
>         On the other hand If I have a group of data with normal vector and
>         centroide that are part of a space.
>
>         I define space like a bedroom.
>         I mean a group of six vectors with its six centroids.
>
>         Then I would like to calculate all the eight edges of this space.
>
>         Thanks and best regards
>
>
>     There is a dedicated intersection function:
>
>     http://doc.cgal.org/latest/Kernel_23/group__intersection__linear__grp.html
>     
> <http://doc.cgal.org/latest/Kernel_23/group__intersection__linear__grp.html>
>
>     you can do something like this:
>
>     typedef CGAL:Exact_predicates_exact_construtions_kernel K;
>     typedef K::Plane_3 Plane_3;
>     typedef K::Point_3 Point_3;
>     typedef K::Vector_3 Vector_3;
>
>
>     Plane_3 p1(Vector_3(x,y,x), Point_3(a,b,c));
>     Plane_3 p2(.....);
>     Plane_3 p3(.....);
>
>
>     boost::optional< boost::variant< Point_3, Line_3, Plane_3 > > res =
>       CGAL::intersection(p1, p2, p3);
>
>     if (res!=boost::none)
>     {
>       if (const Point_3* pt = boost::get<Point_3>(&(*res)))
>       {
>         // pt is the intersection point of the 3 planes
>       }
>       else
>       {
>         if (const Plane_3* pl = boost::get<Plane_3>(&(*res)))
>         {
>         }
>         else
>         {
>           const Line_3* l = boost::get<Line_3>(&(*res));
>           assert(l!=NULL);
>         }
>       }
>     }
>
>     Sebastien.
>
>
>
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>
>
>
>
> --
> Iván Otero González
> Skype: ivanoterouvigo
> Tlf. Lab. 222: 813499
> Tlf. Lab. 218: 813998
> Research Line : ARCHITECTURE AND BUILDING
>
> GeoTech
>
> /Applied Geotechnologies Research Group | Geotech__/
>
> Universidade de Vigo
>
> E.E. Minas
>
> 36310 Vigo (Spain)