CGAL users discussion list

[Iván otero <>]

Hi Sebastien!

Thank you for your help.

I have now this.

    Plane_3 suelo(Point_3(0,0,0), Vector_3(0,0,-1));    // Suelo

    Plane_3 principal( Point_3(0,0,0),Vector_3(0,1,0)); // Principal

    Plane_3 lateral3(Point_3(0,5,0),Vector_3(-1,0,0)); // Lateral 3

    boost::optional<boost::variant<Point_3, Line_3, Plane_3>> res = CGAL::intersection(suelo, principal, lateral3);

    if (res!=boost::none)

    {

        if (const Plane_3* pl = boost::get<Plane_3>(&(*res)))

        {

        }

        else if ( const Line_3* l = boost::get<Line_3>(&(*res)))

        {

            assert(l!=NULL);

        }

        else if ( const Point_3* p = boost::get<Point_3>(&(*res)))

        {

             std::cout<<"el punto es:"<<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?

    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.

    Could you help me?

Thanks and best regards.

2017-02-10 8:05 GMT+01:00 Sebastien Loriot (GeometryFactory) <>:

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

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.



--
You are currently subscribed to cgal-discuss.
To unsubscribe or access the archives, go to
https://sympa.inria.fr/sympa/info/cgal-discuss

--

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)

Attachment: cgal_001.png
Description: PNG image