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9.15.4 Example
LatLonAltBox north43.374north
south42.983south east-0.335east
west-1.423west minAltitude0minAltitude
maxAltitude0maxAltitude LatLonAltBox
9.16 kml:altitudeModeGroup
9.16.1 Structure
kml:altitudeModeGroup ... kml:altitudeModeGroup
9.16.2 Description
Abstract: yes The following elements can be used wherever this element is referenced:
• kml:altitudeMode
Specifies how altitude components are interpreted. See also 9.17 kml:altitudeMode and 6.3 Geometry Interpolation for 3D Earth Browsers.
9.16.3 Content
Type: xsd:anyType Default Value:
none
9.17 kml:altitudeMode
9.17.1 Structure
kml:altitudeMode ... kml:altitudeMode
9.17.2 Description
This element can be used wherever the following element is referenced:
• kml:altitudeModeGroup
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71 Specifies how altitude components are interpreted. If
kml:altitudeMode
is set to
relativeToGround or absolute, altitude components should exist within the coordinate tuples to which it applies.
See also 6.3 Geometry Interpolation for 3D Earth Browsers.
9.17.3 Content
Type: kml:altitudeModeEnumType
Default Value:
clampToGround 9.18
kml:Lod 9.18.1
Structure
kml:Lod id=ID [0..1]
targetId=NCName [0..1] kml:ObjectSimpleExtensionGroup ... kml:ObjectSimpleExtensionGroup [0..]
kml:minLodPixels ... kml:minLodPixels [0..1] kml:maxLodPixels ... kml:maxLodPixels [0..1]
kml:minFadeExtent ... kml:minFadeExtent [0..1] kml:maxFadeExtent ... kml:maxFadeExtent [0..1]
kml:LodSimpleExtensionGroup ... kml:LodSimpleExtensionGroup [0..] kml:LodObjectExtensionGroup ... kml:LodObjectExtensionGroup [0..]
kml:Lod
9.18.2 Description
This element can be used wherever the following element is referenced:
• kml:AbstractObjectGroup
Specifies the level of detail to use when displaying a
kml:Region
. An earth browser should calculate the size of the
kml:Region
when projected onto screen space then compute the square root of the
kml:Regions
area. For example, if an untiled
kml:Region
is square and the viewpoint is directly above the
kml:Region
, this measurement is equal to the width of the projected
kml:Region
. If this measurement falls within the limits defined by
kml:minLodPixels
and
kml:maxLodPixels
, and if the
kml:LatLonAltBox
is in view, then the
kml:Region
should be activated. If this limit is not reached, the associated geometry should not be drawn since it would be too far from the users viewpoint to be
visible.
kml:minLodPixels
shall be less than
kml:maxLodPixels
where a value of -1 = infinite. It is also advised that
kml:minFadeExtent
+
kml:maxFadeExtent
is less than or equal to
kml:maxLodPixels
-
kml:minLodPixels
.
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The following diagram demonstrates how
kml:Lod
is used in the determination of the visibility of a region:
In the following diagram, if P=the calculated projected pixel size, the circled numbers indicate the following:
if P minLodPixels opacity=0
1 in diagram
else ifP minLodPixels + minFadeExtent opacity=P - minLodPixelsminFadeExtent
2 in diagram
else if P maxLodPixels - maxFadeExtent opacity=1
3 in diagram
else if P maxLodPixels opacity=maxLodPixels-PmaxFadeExtent
4 in diagram
else opacity=0
5 in diagram
kml:Lod
shall contain the
kml:minLodPixels
outside of an update context, that is when not a descendant of
kml:Update
. See also 9.13 kml:Region.
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9.18.3 Content
Kategori