Jun 19, 2009

Control Google Earth from Mathematica

This is for Windows platform only. With Mathematica’s .NET link and Google Earth COM API, we can control Google Earth’s camera and add features directly from Matheamtica.

There is an example of planning a shortest tour through every country of the world in Document: FindShortestTour.

SC[{lat_,lon_}]:=r {Cos[lon \[Degree]] Cos[lat \[Degree]],Sin[lon \[Degree]] Cos[lat \[Degree]],Sin[lat \[Degree]]};
r=6378.7;
places=CountryData["Countries"];
centers=Map[CountryData[#,"CenterCoordinates"]&,places];
distfun[{lat1_,lon1_},{lat2_,lon2_}]:=VectorAngle[SC[{lat1,lon1}],SC[{lat2,lon2}]] r;
{dist,route}=FindShortestTour[centers,DistanceFunction->distfun];

Let’s view this example in Google Earth:

Needs["NETLink`"]
InstallNET[];

(* startup google earth *)
ge = CreateCOMObject["GoogleEarth.ApplicationGE"];

(* load path file already generated *)
ge@OpenKmlFile["d:/temp/test2.kml",1]

(* get the camera object *)
cam=ge@GetCamera[1];

(* funcion to ratate the camera *)
runcam[{lat_,lon_}]:=Module[{},
cam@FocusPointLongitude=lon;
cam@FocusPointLatitude=lat;
ge@SetCamera[cam,2]];

(* let's see the movie *)
runcam[#]&/@ centers[[route]];

Here is a low quality video.

 

Here is test2.kml for the shortest path

Here is the recorded tour (shortestrout.kmz) in Google Earth

First load test2.kml to Google Earth, then double click ShortestRoute.kmz to view the animation.

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