CGAL users discussion list

["Max" <>]

> I am using CGAL::Simple_cartesian<double>  as Kernel. for Polyhedron_3.
> In my algorithm I need to compute the intersections of the planes
> induced by the faces of the polyhedra. That seems to work fine.
> But when I try to compute the intersections of the resulting
> intersection lines there seems to be a problem.
> CGAL says there is no intersection, but when I display the lines there
> is an intersection.
> 
> I guess what I need is an intersection test which accepts a delta value
> to be more stable.
> I tried to find a function which computes the minimum distance between
> the lines and the point where this minimum distance occurs, but without
> success.
> 
> Do I need to implement my own tests or can I do this with CGAL? A hint
> would be nice :)
> 
> Best Regards,
> Matthias

CGAL will give the exact result, more exact than what you can see with your
eyes, as long as you are using an exact kernel.

Generally, you should use exact kernel types playing with (nef_)polyhedra.

The predefined Exact_predicates_exact_constructions_kernel is a good choice.

HTH.

B/Rgds
Max