Virtual Earth API: Accurately Position Points in Birdseye

<P>In the Virtual Earth v6 API, one of the new features is improved Birdseye accuracy.&nbsp; The Virtual Earth v6 API has some new methods to more accurately position pushpins when in Birdseye view.&nbsp; </P>
<P>Satellite (Aerial/Hybrid) and Road imagery views are direct overhead views, so calculations to position a pushpin at an exact latitude and longitude are not as complex as in Birdseye.&nbsp; The camera is directly overhead the point and the elevation of that point on the Earth does not need to be taken into account in 2D.&nbsp; However, with Birdseye imagery taken from different angles, there are a lot more variables to consider when calculating where to position a point including the camera position and the elevation of the Earth in that scene.</P>
<P>In order to do this calculation efficiently in Birdseye, a service request is made from the client to the server to get more accurate positions.&nbsp; For some applications, the client-side, less-accurate, faster calculation may be enough to position points.&nbsp; Because of this, enhanced birdseye accuracy for pushpins is off by default in the Virtual Earth API.&nbsp; </P>
<P>To turn on enhanced Birdseye Accuracy for pushpins in the Virtual Earth API, you can make the following call (assuming you have a VEMap instance called "map"):</P>
<BLOCKQUOTE>
<P>map.SetShapesAccuracy(VEShapeAccuracy.Pushpin);</P></BLOCKQUOTE>
<P>To turn off enhanced Birdseye Accuracy for pushpins, you can make the following call:</P>
<BLOCKQUOTE>
<P>map.SetShapesAccuracy(VEShapeAccuracy.None);</P></BLOCKQUOTE>
<P>Here is&nbsp;a link to sample Virtual Earth application showing 3 points on Lombard Street in San Francisco with a checkbox which turns Birdseye Accuracy on and off:</P>
<BLOCKQUOTE>
<P><A href="http://krkinnan.members.winisp.net/samples/v6/birdseye/ve6beaccuracy01.html" mce_href="http://krkinnan.members.winisp.net/samples/v6/birdseye/ve6beaccuracy01.html">Virtual Earth Birdseye Accuracy Sample</A></P></BLOCKQUOTE>
<P>Notice in Aerial view, the 3 yellow dots are positioned at precise points along Lombard Street:</P>
<P mce_keep="true"><A href="http://krkinnan.members.winisp.net/samples/v6/birdseye/ve6beaccuracy01.html"><IMG style="WIDTH: 799px; HEIGHT: 247px" height=247 src="http://krkinnan.members.winisp.net/samples/v6/birdseye/VirtualEarthLombardStreetAerial01.JPG" width=799 border=0 mce_src="http://krkinnan.members.winisp.net/samples/v6/birdseye/VirtualEarthLombardStreetAerial01.JPG"></A> </P>
<P>If you click on "Bird's eye" on the navigation panel and click on different orientations ("N", "W", "E", "S") on the compass in the navigation panel, you will notice the 3 yellow dots are still positioned rather accurately in Birdseye. </P>
<P>Here's a screenshot of the Birdseye scene looking toward the West with enhanced accuracy enabled:</P>
<P><A href="http://krkinnan.members.winisp.net/samples/v6/birdseye/ve6beaccuracy01.html"><IMG style="WIDTH: 414px; HEIGHT: 598px" height=598 src="http://krkinnan.members.winisp.net/samples/v6/birdseye/VirtualEarthLombardStreetBirdseye01.jpg" width=414 border=0 mce_src="http://krkinnan.members.winisp.net/samples/v6/birdseye/VirtualEarthLombardStreetBirdseye01.jpg"></A> </P><img src="http://blogs.msdn.com/aggbug.aspx?PostID=5922610" width="1" height="1">

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