CGAL users discussion list

[马良 <>]

Hi

    I read a STL-file (a kind of file using in RapidPrototyping, a triangle in STL is composed of 3-Point and normal). And I create a Polyhedron like a following.

    Polyhedron P;

    P.make_triangle(V1,V2,V3);

    P.make_triangle(V4,V5,V6);

    ....

    //Then, I create AABB tree, as follows:

    Facet_tree tree(P.facets_begin(),P.facets_end());

 

    //Next, I create a plane and caculate intersections between plane and polyhedron

    Vector nor(0,0,1);

    Point pnt(0,0,0.5);

    Plane plane(pnt,nor);

 

    tree.all_intersections(plane,std::back_inserter(Intersetions));   

 

    //Here, I get intersetions (Points: (X,Y,Z))

    for( it = Intersetions.begin();it !=Intersections.end();it++)

{

    if(CGAL::assign(segment,object) m_segment.push_back(segment);

}

    // But, I get a lot of segments. And Here I want get contours (a contour is composed of segments in order).

    My question is How to constitute contours using segments. Whether or not I must sort those segments by myself? Here is a algorithm in CGAL?

 

Thanks!

--

马良  Mr.MaLiang
State Key Laboratory of Solidification Processing
Northwestern Polytechnical University
Xi'an 710072, Shanxi
P. R. China
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