OGC 07-147r2
Copyright © 2007, 2008 Open Geospatial Consortium, Inc. All Rights Reserved.
21 In the following
kml:Polygon
instance the
kml:altitudeMode
is set to clampToGround.
kml xmlns=http:www.opengis.netkml2.2 Document
Placemark Polygon
altitudeModeclampToGroundaltitudeMode outerBoundaryIs
LinearRing coordinates-135,78.5,300000 -135,12.5,300000 -45,12.5,300000 -
45,78.5,300000 -135,78.5,300000coordinates LinearRing
outerBoundaryIs Polygon
Placemark Document
kml
The outer boundary points of the polygon that are interpolated between the control points in the
kml:LinearRing
form a rectangular perimeter in the plate carrée plane. Then the interior points of the rectangle are filled in linearly in this plane. Finally each long,lat point of the
rectangle is mapped to a long,lat,alt point on the earth terrain surface as shown in Figure 6.
Figure 6: KML Polygon Interpolation in the Plate Carrée Plane
6.3.4 kml:GroundOverlay and kml:Region
The latitude and longitude boundaries for both
kml:GroundOverlay
and
kml:Region
are specified by the elements
kml:west
,
kml:east
,
kml:south
, and
kml:north
. In the case of
kml:GroundOverlay
constant lines of longitude demarcate the portion of the
kml:LatLonBox
boundary corresponding to the values of
kml:west
,
kml:east
and constant lines of latitude demarcate the portion of the boundary corresponding to the values of
kml:south
,
kml:north
. If
kml:altitudeMode
value is not
clampToGround
, as in the
OGC 07-147r2
22
Copyright © 2007, 2008 Open Geospatial Consortium, Inc. All Rights Reserved.
following KML example, then the altitude of the
kml:GroundOverlay
is determined by the
kml:altitude
element.
kml GroundOverlay
altitude500000altitude altitudeModeabsolutealtitudeMode
LatLonBox north80.0north
south60.0south east60.0east
west-60.0west LatLonBox
GroundOverlay kml
The KML example above is shown in Figure 7. If
kml:altitudeMode
value is
clampToGround then the
kml:GroundOverlay
is projected onto the earths terrain surface model similar to the case of the
kml:Polygon
shown on the right hand side of Figure 6.
Figure 7: KML GroundOverlay when value of
kml:altitudeMode
is not clampToGround
In the case of
kml:Region
the values of
kml:west
,
kml:east
of
kml:LatLonAltBox
determine the boundary surfaces of constant longitude and the values of
kml:south
,
kml:north
determine the boundary surfaces of constant latitude. The values of
kml:minAltitude
and
kml:maxAltitude
in the
kml:LatLonAltBox
determine the lower and upper bounding surfaces of constant altitude, respectively.
OGC 07-147r2
Copyright © 2007, 2008 Open Geospatial Consortium, Inc. All Rights Reserved.
23
kml Region
LatLonAltBox north80.0north
south60.0south east60.0east
west-60.0west minAltitude500000minAltitude
maxAltitude2000000maxAltitude altitudeModeabsolutealtitudeMode
LatLonAltBox Region
kml
The spatial extent of the sample
kml:Region
encoded above is depicted in Figure 8.
Figure 8: KML Region when value of
kml:altitudeMode
is not clampToGround
6.4 Shared Styles
