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["Sebastien Loriot (GeometryFactory)" <>]

On 01/27/2015 12:30 PM, Pranav wrote:
> Hi,
>
> I am studying Nef polyhedron documentation. The 1st figure in /Definition/
> section, shows local pyramids for all faces of the polyhedron /P/.
>
> I would like to know the following:
>
> 1. What does /R+/ mean in definition of local pyramid /Q/(in the
> documentation)?
The definition is given in (), it is the set of positive real numbers.

> 2. Since /Pyr/ is defined only for points in d-dimensional space, does
> Pyr(f) where /f/ is a 2-face is compact representation of referring to all
> points in face /f/ at once?
It's any simplex (from dimension 0 to d-1).

> 3. How local pyramid of face /f1/ is Null? I find it a bit confusing because
> as per definition of local pyramid /Q = x + (R+)*(Intersection(P, U(x)) -
> x)/ and here /x/ is a point in the d-dimensional space. It means at least
> /x/ is always a part of /Q/, thereby making it a non-empty set.
It is null if it is a volume not in the nef.

Sebastien.

> -----
> Thanks in advance,
> Pranav
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