CGAL users discussion list

[henrikz <>]

Using only one tetrahedron I get the numbers you mention:

#vertices: 4 (+ 1)
#edges   : 10
#faces   : 10
#cells   : 5

furthermore I get #cells incident to inf vertex = 4, which makes sense.

Yes, in my previous example I had twice these numbers, BUT STILL the same 
  #cells incident to inf vertex = 4
which is (probably) my problem.

I was not trying to build one but TWO (disjoint) tetrahedra, so I was
expecting the number of cells that are connected to the infinite vertex to
also double!?

Possibly I am using the incremental builder wrong, but it only offers
/add_vertex/ and /add_cell/ so I don't really believe it.
Actually I have a very simple reader which just parses the following format
/ Vertices
 8
 0 0 0 0
 1 0 0 0 
 0 1 0 0 
 0 0 1 0 
 2 0 0 0
 3 0 0 0
 2 1 0 0
 2 0 1 0
 Tetrahedra
 2
 1 2 3 4
 5 6 7 8 /

by first adding 8 vertices and then simply adding 2 cells.

I could restate my questions slightly:  is it true that every boundary face
of finite tetrahedra are connected to the infinite vertex by a (different)
infinite cell?
Because in that case I would expect 
  /VH vh_inf = mesh_.infinite_vertex();
  std::vector<CH> inf_cells;
  mesh_.incident_cells(vh_inf, std::back_inserter(inf_cells) );
  std::cerr << "cells incident to inf vertex " << inf_cells.size() <<
std::endl;
/
to yield "8" and NOT "4" for my two disjoint tetrahedra?

Thanks in advance!



--
View this message in context: 
http://cgal-discuss.949826.n4.nabble.com/Infinite-vertex-in-Triangulations-tp1015702p3744195.html
Sent from the cgal-discuss mailing list archive at Nabble.com.