Geometry Boost List: Re: [geometry] 3D box -> 3D multi_polygon conversion

Subject: Re: [geometry] 3D box -> 3D multi_polygon conversion
From: Barend Gehrels (barend_at_[hidden])
Date: 2013-06-11 13:40:25

Hi Tomislav,

On 11-6-2013 12:10, Tomislav Maric wrote:
> Hi everyone,
>
> I need some help with the convert algorithm.
>
> In the online documentation for the convert algorithm
>
> http://www.boost.org/doc/libs/1_54_0_beta1/libs/geometry/doc/html/geometry/reference/algorithms/convert.html
>
> it is stated that
>
> "...a box can be converted to a ring, polygon or multi-polygon, but not
> vice versa."

OK so that statement is not complete, because a 2D 
ring/polygon/multi-polygon is expected. I will adapt it.

>
> However, when I try to use the convert algorithm for a 3D box, it fails
> with the "not implemented" assertion.

So no, that does not work alas...

Our rings/polygons are 2D but they can have a third dimension (height). 
However that third dimension is more a kind of offset-from-zero-level, 
and not used for almost all algorithms up to now. So if you do an 
intersection, that is done in 2D effectively.

Regards, Barend