CGAL users discussion list

[Andreas Fabri <>]

Roger,

did you have a look at the user manual with the examples?

http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Box_intersection_d/Chapter_main.html#Section_61.5

You put a face iterator in your box, so the face iterator
allows you to use ->vertex(i) for the three vertices.

andreas


On 30/05/2011 12:11, Roger Mason wrote:
> Hello Sebastien,
>
> "Sebastien Loriot (GeometryFactory) [via cgal-discuss]"
> <[hidden email] </user/SendEmail.jtp?type=node&node=3560357&i=0>> writes:
>
>  > Something like this.
>  >
>  > typedef
>  >
> CGAL::Box_intersection_d::Box_with_handle_d<double,3,Terrain::Finite_faces_iterator>
>
>  > Box;
>  >
>  > std::vector<Box> boxes;
>  > boxes.reserve(t.number_of_faces);
>  > Terrain t;
>  > Terrain::Finite_faces_iterator fit=t.finite_faces_begin();
>  > for (;fit!=t.finite_faces_end();++it){
>  > CGAL::Bbox_3 bbox=fit->vertex(0)->point().bbox()+
>  > fit->vertex(1)->point().bbox()+
>  > fit->vertex(2)->point().bbox();
>  > boxes.push_back(Box(bbox,fit));
>  > }
>  >
>  > The triangles should be created only in the callback.
>  >
>
> I now have:
>
> ....
>
> Terrain::Finite_faces_iterator fit=L.finite_faces_begin();
> for (;fit!=L.finite_faces_end();++fit){
> CGAL::Bbox_3 bbox=fit->vertex(0)->point().bbox()+
> fit->vertex(1)->point().bbox()+
> fit->vertex(2)->point().bbox();
> boxesL.push_back(Box(bbox,fit));
> }
>
> std::vector<Box> boxesS;
> boxesS.reserve( S.number_of_faces() );
>
> fit=S.finite_faces_begin();
> for (;fit!=S.finite_faces_end();++fit){
> CGAL::Bbox_3 bbox=fit->vertex(0)->point().bbox()+
> fit->vertex(1)->point().bbox()+
> fit->vertex(2)->point().bbox();
> boxesS.push_back(Box(bbox,fit));
> }
>
> // See Help/CGAL/cgal_manual.pdf Chapter 61.7
> // run the intersection algorithm and store results in a vector
> std::vector<std::size_t> result;
> CGAL::box_intersection_d( boxesS.begin(), boxesS.end(), boxesL.begin(),
> boxesL.end(),
> report( std::back_inserter( result)),
> std::ptrdiff_t(1), CGAL::Box_intersection_d::HALF_OPEN);
>
> // sort and show results
> std::sort( result.begin(), result.end());
> std::cout << "There are " << result.size() << " potential intersections"
> << std::endl;
> std::copy( result.begin(), result.end(),
> std::ostream_iterator<std::size_t>( std::cout, " "));
> std::cout << std::endl;
>
> The output is, I assume, a list of box id's. How do I extract the
> vertices of the triangles in these boxes?
>
> Any help you give is most appreciated, but if you don't have time, I
> understand.
>
> Best wishes,
> Roger
>
> ------------------------------------------------------------------------
> View this message in context: Re: Intersection of surfaces
> <http://cgal-discuss.949826.n4.nabble.com/Intersection-of-surfaces-tp3549940p3560357.html>
> Sent from the cgal-discuss mailing list archive
> <http://cgal-discuss.949826.n4.nabble.com/> at Nabble.com.


--
Andreas Fabri, PhD
Chief Officer, GeometryFactory
Editor, The CGAL Project

phone: +33.492.954.912    skype: andreas.fabri