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

• To: mathgroup at smc.vnet.net
• Subject: [mg67903] Re: 3D plot of globe (map of world)?
• From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
• Date: Wed, 12 Jul 2006 05:06:03 -0400 (EDT)
• Organization: Uni Leipzig
• References: <e8vu3v$t2i$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

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!
|
| 

• Follow-Ups:
  • Re: Re: 3D plot of globe (map of world)?
    • From: "Adel Elsabbagh" <aelsabbagh@gmail.com>