CGAL users discussion list

[Marc Glisse <>]

On Mon, 23 Jan 2012, Juan Carlos Lopez Alfonso wrote:

> Hi  Sebastien:
> About your question: The points of an almost coplanar thetraedra are not in
> plane with axis aligned normal vectors. In one of my emails, I sent a real
> example of a resultant thetraedra, where the points of its vertices are
> almost coplanar when I use the coplanar test of CGAL:
>
> p1x = 0.00000000000000000;
> p1y = 0.20000000000000001;
> p1z = 0.00000000000000000;
>
> p2x = 0.20000000000000001;
> p2y = 0.20000000000000001;
> p2z = 0.20000000000000001;
>
> p3x = 0.40000000000000002;
> p3y = 0.80000000000000004;
> p3z = 1.00000000000000000;
>
> p4x = 0.20000000000000001;
> p4y = 0.40000000000000002;
> p4z = 0.40000000000000002;

I don't know where your coordinates are coming from, but assuming they are 
all of the form: some integer / 10, it would be preferable to work with 
the integers directly instead of scaling by 10 (which introduces rounding 
errors).

--
Marc Glisse