CGAL users discussion list

["Laurent Rineau (CGAL/GeometryFactory)" <>]

Le Thursday, February 9, 2017 4:40:13 PM CET Iván otero a écrit :
> Hi Laurent!
> 
> 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.

There is a constructor of a `CGAL::Plane_3<K>` from a point and a vector:

  http://doc.cgal.org/latest/Kernel_23/classCGAL_1_1Plane__3.html

 
        Plane_3 (const Point_3< Kernel > &p, const Vector_3< Kernel > &v)

          introduces a plane h that passes through point p and that is 
orthogonal
      to v. 


And then you will have to use the intersection function:

  http://doc.cgal.org/latest/Kernel_23/group__intersection__linear__grp.html


The intersection of the two first `Plane_3<K>` will gives you a `Line_3<K>`, 
unless the plans are parallel. Then the intersection of the resulting 
`Line_3<K>` with the third `Plane_3<K>` should give you a `Point_3<K>`, 
unless the line is parallel to the plane.

-- 
Laurent Rineau, PhD
R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
Release Manager of the CGAL Project       http://www.cgal.org/