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Re: Re: 3D plot of globe (map of world)?

• To: mathgroup at smc.vnet.net
• Subject: [mg67953] Re: [mg67903] Re: 3D plot of globe (map of world)?
• From: "Adel Elsabbagh" <aelsabbagh at gmail.com>
• Date: Thu, 13 Jul 2006 06:55:33 -0400 (EDT)
• References: <e8vu3v$t2i$1@smc.vnet.net> <200607120906.FAA22222@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi Jens,
I feel curious to try your code although I don't think I will ever use
it. However I get the error message:

Syntax::sntxb:
Expression cannot begin with "Import[\[LeftSkeleton]2625\
\[RightSkeleton]][[1, 1]]".

Thanks!
Adel

On 7/12/06, Jens-Peer Kuska <kuska at informatik.uni-leipzig.de> wrote:
> Hi,
>
> what is with
>
> img = Import[
> "http://phong.informatik.uni-leipzig.de/~kuska/oglscript/EarthMap.png"][[1,
> 1]];
>
> img = First /@ Partition[(First /@ Partition[#,
> 2]) & /@ img, 2];
>
> {n, m} = Take[Dimensions[img], 2];
>
> dth = Pi/n;
> dphi = 2Pi/m;
> spdata = MapIndexed[
> {{Pi, 2Pi}*#2/{n, m}, N[#/255]} &, img, {2}];
>
>
> onSphere[th_, phi_] := {Sin[th]*Cos[phi],
> Sin[th]*Sin[phi], Cos[th]}
>
> expandPoly[t_, phi_] :=
> With[{th = Pi - t},
>  Polygon[{onSphere[th, phi], onSphere[th, phi +
> dphi],
>           onSphere[th + dth, phi + dphi],
> onSphere[th + dth, phi]}]
> ]
>
> poly = Map[{SurfaceColor[RGBColor @@ #[[2]]],
> expandPoly @@ #[[1]]} &,
> spdata, {2}];
>
> Show[Graphics3D[{EdgeForm[], poly},ViewPoint ->
> {-2.602, -2.019, 0.777}]]
>
> only clouds and mountains can make the picture
> better.
>
> Regards
>
>  Jens
>
>
>
> "Xiangdong Liu" <liu at vtaix.cc.vt.edu> schrieb im
> Newsbeitrag news:e8vu3v$t2i$1 at smc.vnet.net...
> | Hi!
> |
> | Not sure if this question has been asked before
> but does anyone know how
> | to make a 3D plot of the world or globe?  Or at
> least the map of a continent
> | on a 3D globe?
> |
> | With the `WorldPlot` package, you can plot 2D
> world map or country/continent
> | maps, with various 3D-to-2D projections.  Yet,
> Mathematica does not seem to
> | provide a means to easily plot the map data in
> 3D (well as far as I know).
> |
> | Mathematica does allow the per-country map data
> (polygons) to be referenced
> | but does not allow (as far as I can see) map
> data of a continent to be
> | referenced collectively.  I am looking therefore
> into if I can do the
> | tedious country by country plots and then
> combine them.  Yet, the map data
> | for some countries, such as US, consists
> multiple disjoint polygons.  But
> | if you use ListPlot or ListPlot3D, Mathematica
> connects all polygons as if
> | they were one, adding superfluous edges.
> Manually separating map data for
> | such countries into multiple indpendent lists
> and plotting the lists
> | separately and then combining them, whew, seems
> to be too tedious to be
> | doable.
> |
> | Thanks!
> |
> |
>
>
>


-- 
Adel Elsabbagh

• References:
  • Re: 3D plot of globe (map of world)?
    • From: "Jens-Peer Kuska" <kuska@informatik.uni-leipzig.de>