CGAL users discussion list

[Olivier Devillers <>]

Le 5/2/13 7:34 AM, Pranav a écrit :

I want to know how vertices in a tetrahedron are ordered in CGAL given a coordinate system & an assumed Handed-ness (say Right Handed assumed to be positive orientation).

I have seen the Figure 39.1 here:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Triangulation_3/Chapter_main.html
but still i am not clear with how to assign indices 0,1,2,3 to the vertices of an arbitrarily positioned and oriented tetrahedron in R³ space. : The four vertices of a cell are indexed with 0, 1, 2 and 3 in positive orientation, the positive orientation being defined by the orientation of the underlying Euclidean space ℝ³ (see Figure 39.1).


that's all.
Any of the 12 positive permutations are fine.

(actual ordering depends on algorithmic details such that order of insertion of the points...)