[Geoserver-users] KML output, extruding height with polygons

[karsten <ka...@te...>]

Hi,
 
we are pretty new to Geoserver and KML output for GE. We have been working
on using kml output of postgis based layers to dynamicayyl cerate kml via
Geoserver and to extrude height values to view features e.g. building in 3D.
So far this sucessfully worked for us with a heigth.ftl template and  point
layers , but it doesnt seem to work as well with polygons. These polygons in
this link to a kmz file output by Geoserver
http://www.terragis.net/docs/other/test_height.kmz won't extrude. 

If you open and zoom-in enough so the data is presented as kml entities and
right click, you will notice inside the properties that the "altitude" tab
is set to "various heights (min=0 and max=max value)"  instead of using the
unique Absolute Height of "max value" ( see screen shot
http://www.terragis.net/docs/other/test_height.png). Hence they stick to the
ground. If you manually change that value to force the later, you will
notice  that the polygon renders properly. So the problem is probably with
the writing of the file when created in geoserver. 
 
While researching this we also realized that the kml output does produce a
MultiGeometry and has actually a point (the center point of the polygon and
does correctly add the height value, below 154 to it) , plus the polygons
bit with the polygon feature the z values all default to 0 - see below .
However we are not sure why a point  is created at all (as the layer is
polygons only and guess that if we could suppress the point form being
created that the polygons heights would show up correctly ?


Anybody has found a similar problem and/or can venture a solution?


I have also set it up in this page http://dr-i-ve.com/samples-for-geogroup/
as the first file on the upper left ( 3D Buildings 2002) , and I have set
two other files that render properly z values (height) for reference.

Luis and Karsten
 
 
-------------------
<MultiGeometry>
<Point>
<coordinates>-122.3315613282126,47.62726284173768,154</coordinates>
</Point>
<Polygon>
<outerBoundaryIs>
<LinearRing>
<coordinates>
-122.33179025,47.62764347000001,0 -122.33174006,47.62760903,0
-122.33169852,47.6276373,0 -122.33120259,47.62764013,0
-122.33120192,47.62761704,0 -122.33115272,47.62761676,0
-122.33113577,47.62759119,0 -122.33111383,47.62755700000001,0
-122.3310926,47.62751601,0 -122.33107405,47.62747254000001,0
-122.33105908,47.62742717,0 -122.33104675,47.62737868,0
-122.33103897,47.62733013,0 -122.33103796,47.62729503999999,0
-122.33087857,47.62729575,0 -122..3308763,47.62721695,0
-122.33088906,47.62721741,0 -122.33088952,47.62720139,0
-122.3308203,47.62720213,0 -122.33081998,47.62696679,0
-122.33093383,47..62696591,0 -122.33093528,47.62695296,0
-122.33105642,47.6269526,0 -122.33105498,47.62696554,0
-122.33129907,47.62696418,0 -122.33129875,47.6269531,0
-122.33132425,47.62695276,0 -122.33132503,47.62694844000001,0
-122.33143164,47.62694889,0 -122.33143122,47.62696613,0
-122.33191168,47.62696289,0 -122..33191136,47.62698321000001,0
-122.3319615,47.62698441000001,0 -122.33202638,47.62699156000001,0
-122.33208041,47.62700130999999,0 -122.33213642,47.62701659,0
-122.33220642,47.62704337,0 -122.33224275,47.62706373,0
-122.33235145,47.62713712,0 -122.3323286,47.62715034,0
-122.3323759,47.62717928,0 -122.33230481,47.62722547999999,0
-122.33235638,47.62726082,0 -122.33179025,47..62764347000001,0 
</coordinates>
</LinearRing>
</outerBoundaryIs>
</Polygon>
</MultiGeometry>