[Gvsig_english] oracle spatial wrong interpretation ofrectangles (at least 3d)

[Benjamin Ducke]

It makes sense to me: like you can define a 2D rectangle by giving
just the top-left and bottom-right extreme coordinate pairs (x1,y1) 
and(x2,y2), you can define a cuboid perfectly well by giving the 
two extreme 3D points (x1,y1,z1) and (x2,y2,z2).
Since the whole structure is by definition orthogonal 
(all interior angles are 90 degrees), this information is enough 
to construct the entire cube.

Ben


----- Original Message -----
From: "G. Allegri" <giohappy at gmail.com>
To: "Users and Developers mailing list" <gvsig_internacional at runas.cap.gva.es>
Sent: Tuesday, January 19, 2010 12:21:54 PM GMT +01:00 Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna
Subject: Re: [Gvsig_english] oracle spatial wrong interpretation ofrectangles (at least 3d)

I honestly think that the 3d rectangle (cuboid) structure in oracle is
erroneous. It is defined as (x1,y1,z1,x2,y2,z2), which lets the other
two vertices without a Z definition (and this lets the user decide
what assign them...), while it would have been consistent if it was
(x1,y1,y1,y2,z): this define completely a cuboid (with a fixed Z for
all the vertices).
So, I would avoid using them but they exist and may create problems
for viewers.

What to do? In a 2D canvas I would simply discard the Z, while in a 3D
env I would simply use the first one (subjective but argumentative).
This is just a workaround to not break the viewer, not a consistent
choice...

giovanni
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