CGAL users discussion list

[Peter Hachenberger <>]

Hi Ruben,

can you please send me the whole example. Nef_polyhedron_3 does not work
with arbitrary transformations. Scaling and translation works fine,
rotation works if you know how to do it. As soon as the matrix inverts
the orientation or the polyhedron is skewed, you will have problems.

Peter

On Sat, 2007-09-01 at 11:56 +0200, Rubén Martínez wrote:
> Hi !!!
> 
> I need some help with de aff transformation 3.
> 
> I have this code:
> 
> double m[16];
> 
> // Initialize m[ i ] with my transf
> 
> CGALTransf TAfin (    m[0], m[1],  m[2], m[3],
>  m[4], m[5], m[6], m[7],
>  m[8],m[9],m[10], m[11],);
> 
> // N is a nef polyedra
> 
> N.transform( TAfin );
> 
> My problem is that no aply correctly the transformations. Why? I dont
> know, because I use this other code:
> 
> m[3] =5.0;
> m[7]=5.0;
> 
> CGALTransf TAfin (    m[0], m[1],  m[2], CGAL::Gmpz(m[3]),
>  m[4], m[5], m[6], CGAL::Gmpz(m[7]),
>  m[8],m[9],m[10], m[11],);
> 
> // N is a nef polyedra
> N.transform( TAfin );
> 
> In this case the aff trans run correctly, btu if I use the coge
> CGAL::Gmpz with all th elements of the matrix I not obtain any result,
> there are not trnaformation.
> The aff trnasf only run correctly when the data is a const double
> introduces by me in the code.
> 
> I need help, How I obtain it? I need obtain de transf with the matrix
> m initializes in other site with elemens double.
> 
> Bye!