CGAL users discussion list

[Ole Rehmsen <>]

Am 16.12.2009 um 15:28 schrieb Laurent Rineau (GeometryFactory):

> Le mercredi 16 décembre 2009 19:32:44, Ole Rehmsen a écrit :
>> Hey everyone,
>> 
>> I could not find an answer in the FAQ, the documentation or the mailing
>> list archives. I am using the CDT to triangulate a set of points lying in
>> the x-y-plane, but later would like to elevate these points (in z
>> direction). I stumbled across Triangulation_euclidean_traits_xy_3 which
>> basically allows just that, only for the non-constraint Delaunay
>> triangulation. Is it somehow possible to use 3D points for a CDT that
>> simply ignores the z coordinate?
> 
> Do your constraints intersect, or might intersect? Because, in case of an 
> intersection, the difficulty is choose a z coordinate for the intersection.
> 

No, the constraints form a simple, not necessarily convex polygon. For my 
application, it would be fine if the triangulation would completely ignore 
the z-values. The only reason I want them there is that I will afterwards do 
some processing that will involve finding the desired z values. The other 
approach for me would be to convert the whole triangulation into a data 
structure that allows 3-D points by simply choosing z=0, which is also 
possible, but not very efficient. That's why I thought there might be a 
better way (as there is one for non-constrained Delaunay triangulations).

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