CGAL users discussion list

[Philipp Moeller <>]

Nicholas Mario Wardhana 
<>
 writes:

> On 9 March 2012 06:49, Helmi Ben Hmida
> <>
>  wrote:
>> Hello Again,
>> U re right, but, it did not resolve the problem.
>> Still empty polyderon !!!
>> Do any one know how o fix this please
>>
>>
>> This is the correct off
>>
>> OFF
>> #
>> #Oid806_IfcWall_Wand__Mauerziegel_d_17_5_cm__i.OFF
>> #
>> 24 6 24
>> 19.454456 9.214429 9.195417
>> 19.454456 9.214429 6
>> 19.629456 9.214429 6
>> 19.629456 9.214429 9.195417
>> 19.629456 9.214429 9.195417
>> 19.629456 9.214429 6
>> 19.629456 13.049429 6
>> 19.629456 13.049429 8.724564
>> 19.629456 13.049429 8.724564
>> 19.629456 13.049429 6
>> 19.454456 13.049429 6
>> 19.454456 13.049429 8.724564
>> 19.454456 13.049429 8.724564
>> 19.454456 13.049429 6
>> 19.454456 9.214429 6
>> 19.454456 9.214429 9.195417
>> 19.454456 9.214429 6
>> 19.454456 13.049429 6
>> 19.629456 13.049429 6
>> 19.629456 9.214429 6
>> 19.629456 9.214429 9.195417
>> 19.629456 13.049429 8.724564
>> 19.454456 13.049429 8.724564
>> 19.454456 9.214429 9.195417
>> 4 0 1 2 3
>> 4 4 5 6 7
>> 4 8 9 10 11
>> 4 12 13 14 15
>> 4 16 17 18 19
>> 4 20 21 22 23
>>
>
> Hi Helmi,
>
> I am not sure about this, but while I understand that you want to
> create a cube with each face being defined as a square (unlike your
> previous OFF file, the new one can be successfully loaded to Meshlab,
> which means this is a valid OFF file), this causes your file to
> contain duplicate vertices. I am wondering if anybody can clarify
> whether Polyhedron_3 allows duplicate vertices?

The Polyhedron will be loaded alright but it will not be what you would
expect (no filtering on the vertices is done). This could be implemented
in an Incremental_builder [1] maybe with an epsilon for tricky cases
where the vertices diverge slightly.

>
> Also, if you receive any error message, it might be helpful to put it here.
>
> Best regards,
> Nicholas

-- 
Philipp Moeller
GeometryFactory

[1] : 
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Polyhedron_ref/Class_Polyhedron_incremental_builder_3.html