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[Noel Warren <>]

So here we have two triangles that make a kind of bow-tie.  Do you want this to be a Nef_polyhedron_3 too?  In this case I would follow the procedure I mentioned before, using the Nef constructor.  Why do you want such a Nef?  Just curious

2012/7/25 Luis Rodriguez <>

OFF

5 2 0

1073.91 -220.538 13.15

1073.91 -220.688 13.15

1074.26 -220.688 13.15

1074.26 -220.538 13.15

1074.08 -220.613 13.15

3 1 4 0 

3 4 2 3 

Here is another example, this is not closed. the last one was an example of a closed Polyhedron with more than 8 points, maybe I misunderstood your question before 

On Wed, Jul 25, 2012 at 2:03 PM, Noel Warren <> wrote:

I've poked around a little and it looks fine to me. The right number of points and faces (Providing it's triangulated) are there so I can't see why it shouldn't give a true result for is_closed.  Are you sure this one gives false?

2012/7/25 Luis Rodriguez <>

OFF

16 28 0

1077.03 -219.203 15.895

1079.22 -221.791 15.895

1079.22 -217.761 15.895

1073.91 -220.483 15.82

1077.03 -219.203 15.82

1079.22 -217.761 15.82

1079.22 -221.791 15.82

1077.03 -221.791 15.895

1077.03 -221.791 15.82

1077.03 -220.483 15.82

1073.91 -220.483 15.895

1077.03 -220.483 15.895

1073.91 -219.203 15.895

1073.91 -219.203 15.82

1077.03 -217.761 15.82

1077.03 -217.761 15.895

3 10 11 12 

3 7 1 11 

3 12 11 0 

3 11 1 0 

3 0 1 2 

3 0 2 15 

3 4 3 13 

3 6 8 9 

3 9 3 4 

3 6 9 4 

3 5 4 14 

3 6 4 5 

3 7 8 1 

3 1 8 6 

3 11 9 7 

3 7 9 8 

3 10 3 9 

3 10 9 11 

3 12 13 3 

3 12 3 10 

3 13 0 4 

3 13 12 0 

3 15 14 4 

3 15 4 0 

3 14 2 5 

3 14 15 2 

3 1 6 2 

3 6 5 2 

Here is an example, thank you 

On Wed, Jul 25, 2012 at 12:13 PM, Noel Warren <> wrote:

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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