CGAL users discussion list

[Peter Hachenberger <>]

Hi,

Sorry, but your question is not precise. You want to extract the
intersection of a polyhedron and a plane? It works like this:

Nef_polyhedron N0;
// ...
Nef_polyhedron N1(Plane(1,0,0,-1), Nef_polyhedron::INCLUDED);
N1 = N1.boundary();
Nef_polyhedron R = N0.intersection(N1);

Peter

On Sat, 2007-12-29 at 23:27 +0800, loadcom wrote:
> I have looked up the CGAL manual, but I got no direct answer.
> 
> I guess it's created as the intermediate result of the AND operation
> of 
> 2 existing nef-polyhedra. e.g:
> 
> Nef_polyhedron N0;
> // ...
> Nef_polyhedron N1(Plane_3( 1, 0, 0,-1),Nef_polyhedron::EXCLUDED);
> N0 -= N1; // during this op, the cutting polygon should be already
> created
> 
> But how can I get this result?
> 
> Or, as an coarse implementation, as far as efficiency is concerned, I
> may
> get the result I needed, in another form, using:
> 
> Nef_polyhedron N2(Plane_3( 1, 0, 0,-1),Nef_polyhedron::INCLUDED);
> N0 -= !N2;
> 
> N0 will be the resulting slice of cutting Plane_3( 1, 0, 0,-1) with
> N0,
> but, still, how can I get the polygon from the Nef_polyhedron data
> structure?
> 
> Any help or hints will be appreciated.
> 
> Max
> 
>  
> 
> 
> Re：[cgal-discuss] How to get resulting polygen of cutting a
> polyhedron with a plane?
> 
> Hello,
> 
> I have a maybe simple question:
> 
> How to get resulting polygen of cutting a polyhedron with a plane?
> 
> Many thanks.
> 
> Max
> 
> 
> 
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