[Gmsh] Help

[Christophe Geuzaine]

Hi - Look for Geo/SOrientedBoundingBox.h in the source code: it does 
what you want. It's not interfaced in the parser, though.

On 17/06/10 11:26, Henri Pascal-Jenny wrote:
> Hi
>
> I am facing the problem of _finding the minimum-3D box enclosing AS
> CLOSE AS POSSIBLE a set of 3D mesh points_ .
>
> I would like to avoid the use of a too-sophisticated algorithm .
>
> (cf. http://en.wikipedia.org/wiki/Minimum_bounding_box_algorithms)
>
> Actually, when used straightforwardly, the method “BoundingBox”
> available in a gmesh-session returns a 3D box
>
> which box does not always correspond to the minimum volume enclosing the
> set of points
>
> /( imagine a thin and not fully-planar shape tilted in respect to the
> axes of a standard coordinates-frame )/
>
> / /
>
> In fact, the matter comes from the bulk orientation of the envelop of
> the set of points under consideration.
>
> The usage is :
>
> BoundingBox { expression, expression, expression, expression,
> expression, expression };
>
> what forces the bounding box of the scene to the given expressions (X
> min, X max,
>
> Y min, Y max, Z min, Z max).
>
> Therefore, I am wandering if there is a way of operating the
> “BoundingBox” method in order to get in the end the truly-minimum 3D box
> enclosing.
>
> Actually, I guess that there is a preliminary thing to do related to the
> coordinates system ; maybe I am wrong.
>
> Well, I would appreciate it very much if anyone could supply me for any
> piece of information regarding my problem.
>
> Thanks a lot in advance for your attention and your cooperation.
>
> Regards
>
> Henri Pascal-Jenny
>
>
>
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh


-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine