CGAL users discussion list

[Sylvain Pion <>]

Andre Massing wrote:
> A small question has remained..
>
> Sylvain Pion wrote:
> > Hi Andre,
> >
> > Andre Massing wrote:
> > > first of all, I  want to thank the developer behind the CGAL project 
> > > for providing such a well-documented, open-source computational 
> > > geometry library. We just started to use it in our mesh classes of 
> > > our FEM library dolfin for providing some intersection detection and 
> > > computation, and it is actually quite fun to work with.
> >
> > Excellent !
> >
> > > Since we intend to use intersection quite heavily I have been 
> > > wondering, why certain intersection test in 3D have not yet been 
> > > implemented, such as the following
> > >
> > > ‘do_intersect(Point_3&, Point_3&)’
> > > primitive_intersection_test.cpp:79: error: no matching function for 
> > > call to ‘do_intersect(Point_3&, Segment_3&)’
> > > primitive_intersection_test.cpp:81: error: no matching function for 
> > > call to ‘do_intersect(Point_3&, Tetrahedron_3&)’
> > > primitive_intersection_test.cpp:84: error: no matching function for 
> > > call to ‘do_intersect(Segment_3&, Segment_3&)’
> > > primitive_intersection_test.cpp:86: error: no matching function for 
> > > call to ‘do_intersect(Segment_3&, Tetrahedron_3&)’
> > > primitive_intersection_test.cpp:93: error: no matching function for 
> > > call to ‘do_intersect(Tetrahedron_3&, Tetrahedron_3&)’
> > >
> > > in particular the Point_3/another primitive are missing. Is there any 
> > > special reason for that, a principle obstacle for implementing this 
> > > correctly or do I just not use the right functions?
> >
> > For do_intersect(Point_3 p, X x), x.has_on(p) provides a similar 
> > functionality.
>
> There exists a Triangle_3_Point_3_do_intersect function in CGAL, which 
> seems at a first glance not rely on the x.has_on(p) function. Is there 
> any special reason for that?

Probably no good one.

--
Sylvain Pion
INRIA Sophia-Antipolis
Geometrica Project-Team
CGAL, http://cgal.org/