CGAL users discussion list

[Manuel Caroli <>]

Hi Santosh,

Santosh Tiwari wrote:
> Hello,
>
> I am learning to use CGAL.
>
> I want to output the vertices of a list of Facets on the screen. How do I do
> it?
>
> Any help or references would be appreciated. Following is the code snippet,
> I am using.
The triangulation data structure stores facets only implicitly:
http://www.cgal.org/Manual/3.3/doc_html/cgal_manual/TriangulationDS_3/Chapter_main.html
http://www.cgal.org/Manual/3.3/doc_html/cgal_manual/TriangulationDS_3_ref/Concept_TriangulationDataStructure_3.html

Short explanation:
A facet is represented as a pair of a Cell_handle ch of a cell to which 
the facet is incident and an int i such that ch->vertex(i) gives you the 
only vertex that is not incident to the facet (the opposite vertex).
To output the all vertices of the facet f you could do something like
std::cout<<f.first->vertex((f.second+1)%4)<<", "
         <<f.first->vertex((f.second+2)%4)<<", "
         <<f.first->vertex((f.second+3)%4)<<std::endl;

Best

Manuel