CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Max Harris wrote:
> CGAL::convex_hull_3 is very nice, but the resulting polyhedron is 
> triangulated (which it has to be, because the polyhedron is calculated by the 
> quickhull algorithm), which is bad for my application.
>
> How should I go about removing the unnecessary edges? Or to put it another 
> way, how do I go about combining all of the coplanar triangular faces into 
> new faces? Is there a built-in way to do this, or an example?

Unfortunately, there is no built-in way to do it, you need to play with
the functions:

join_facet
join_vertex
erase_center_vertex

all documented here:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Polyhedron_ref/Class_Polyhedron_3.html

and with the coplanar and collinear functions:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Kernel_23_ref/Function_coplanar.htm
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Kernel_23_ref/Function_collinear.html



S.