Returns the real world coordinates on the terrain, behind a specified pixel on the window. If the selected pixel is part of an object, the object is also returned.
pixelToWorld([pixelX], [pixelY], [type]);
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Parameter |
Description |
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pixelX |
Optional, default: undefined. If this parameter is not specified, the method assumes that the x coordinate of the center of the window is requested The left-right coordinate in pixels of a specified point on the window |
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pixelY |
Optional, default: undefined. If this parameter is not specified, the method assumes that the y coordinate of the center of the window is requested The top-bottom coordinate in pixels of a specified point on the window |
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type |
Optional, default: sgPixelToWorldTypeAll Can be one of the following values: sgPixelToWorldTypeTerrain –queries only the coordinates on the terrain. If there is a terrain object behind the specified screen pixel, the object is ignored. sgPixelToWorldTypeAll –queries the terrain coordinates and the objects coordinates. If this flag is specified and there is a terrain object (e.g., polygon) behind the specified screen pixel, the return value will contain the object coordinates. |
Return Value
Null if the pixel hits the sky, otherwise an object with three properties: coord, distance node.
The coord property is an SGCoord3D object that indicates where in the 3D world the pixel hit. The distance property indicates the distance from the pixel (camera) to the returned coordinate. The node property is null if behind the specified pixel there is only terrain. Otherwise, if a terrain object such as 3D polygon is behind the pixel, the node property of the return value contains an SGNode object that represents the terrain object.
Remarks
If none of the parameters is specified, the method returns information about the center pixel of the window
Example
The following example illustrates the use of the pixelToWorld method.
function centerWindowToWorld()
{
var ret = globe.window.pixelToWorld();
if (ret != null)
{
var terrainX = ret.coord.x.toFixed(5);
var terrainY = ret.coord.y.toFixed(5);
var distToTerrain = ret.distance.toFixed(1);
var s = "Terrain coordinate at window center:\n"
s += terrainX + " , " + terrainY + "\n\n";
s += "Distance to terrain: "+ distToTerrain +" meters";
alert(s);
}
else
alert("Window center coordinate hit the sky");
}