CGAL users discussion list

[Noel Warren <>]

That's odd.  Can you send me one of them?  I assume you're  using the IO package to create your Polyhedron_3.

2012/7/25 Luis Rodriguez <>

Some of my OFF files have more than 8 points, they vary between 9 and 36 but most of them have 8.

Luis

On Wed, Jul 25, 2012 at 11:57 AM, Noel Warren <> wrote:

Well, I don't know of any out of the box method for "cleaning up" polyhedrons with CGAL.  But here is the basic approach...

Iterate through all the halfedges.  Each halfedge should have two half facets.  If it has more or less then you've encountered a problem.  You could then proceed to try to either get rid of excess geometry or add missing faces.

Before you do any of that, a question; Is it possible that your OFF file redefines points for every facet?  In this case a cube would have 24 points instead of 8.

2012/7/25 Luis Rodriguez <>

Well I never thought about that, I just believed on the is_closed test because that is what I needed and I am working with around 2000 files so I didn't get into detail. But how can I check that? 

My off files come from VRML and when I open any .wrl file the objects look complete so I don't know. 

Luis

On Wed, Jul 25, 2012 at 11:37 AM, Noel Warren <> wrote:

Do you know why it isnt cosed? Are there faces missing or is there "extra" geometry? Or both?

Luis Rodriguez <> escribió:

>Hi,
>
>I am working with Polyhedrons_3 created from OFF files, it is required to
>get is_closed == true before I can transform to Nef_polyhedron. If I get
>is_closed == false, is there a way I can modify my polyhedron to become
>closed?
>
>any help is appreciated, thank you.
>
>Luis R
>

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