CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

This is a documentation bug, the return type can also be Triangle_3.

S.

Bernhard Kornberger wrote:
> Hello,
>
> In CGAL 3.8 there is an option to intersect two 3D triangles,
> where the return type is Point_3, Segment_3 or vector<Point_3>.
>
> http://tinyurl.com/3ezcvbd
>
> The return type "vector<Point_3>" seems to be undocumented, and I
> assume that such a vector is returned in case of coplanar inter-
> secting triangles, when the intersection is an area, right? I made
> a test, and it does not work as expected, here is a minimal
> example:
>
>
> #include <stdio.h>
> #include <iostream>
> #include <CGAL/Exact_predicates_exact_constructions_kernel.h>
> typedef CGAL::Exact_predicates_exact_constructions_kernel K;
> typedef K::Triangle_3 Triangle_3;
> typedef K::Point_3 Point_3;
> typedef K::Segment_3 Segment_3;
>
>
> using namespace std;
>
>
> int main(int argc,char* argv[])
> {
>
>         Point_3 a(0,0,0);
>         Point_3 b(0,1,0);
>         Point_3 c(1,1,0);
>         Point_3 d(0.5,1,0);
>         Point_3 e(3,1,0);
>         Triangle_3 t0(a,c,b);
>         Triangle_3 t1(a,e,d);
>
>         if(!do_intersect(t0,t1))
>         {
>                 cout<<"No intersection"<<endl;
>                 return 0;
>         }
>
>         vector<Point_3> vPoints;
>         Point_3 p;
>         Segment_3 seg;
>
>         CGAL::Object obj=CGAL::intersection(t0,t1);
>         if(CGAL::assign(p,obj)) cout<<"Intersection type: Point"<<endl;
>                 else if(CGAL::assign(seg,obj)) cout<<"Intersection type: 
> Segment"<<endl;
>                         else if(CGAL::assign(vPoints,obj)) 
> cout<<"Intersection type: Area"<<endl;
>                                 else cout<<"Hm?"<<endl;
>
>
>         return 0;
> }
>
> ...says just "Hm?". Any hints?
>
> Best regards
> Bernhard Kornberger