KML, COLLADA, Goolge Earth: using spline tag in COLLADA

Hi,

i am new in kml and Collada. I bought the book “COLLADA Sailing the Gulf of 3D Digital Content Creation” to learn how can i use COLLADA. I did try to use spline tag in my dae file (from Chapter4: Curve Interpolation) but i cannot see anything in Google Earth.
Can you please help me? It would be nice of you.

P.S.: please see my code below. I hope i am right here in this Forum.

Thanks.
Best regards.
Sphere

KML Code:
<?xml version=“1.0” encoding=“UTF-8”?>
<kml xmlns=“http://www.opengis.net/kml/2.2”>
<Folder>
<name>LinearSpline</name>
<description>An Example to try using Linear Spline</description>
<LookAt>
<latitude>36.08260761307279</latitude>
<longitude>-112.2552505069063</longitude>
<range>1500.0</range>
</LookAt>
<Style id=“BackColor”>
<LineStyle>
<color>7f00ff00</color>
<width>1005</width>
</LineStyle>
</Style>
<Placemark>
<name>Model</name>
<description><![CDATA[]]></description>
<Style id=‘default’>
<styleUrl>#BackColor</styleUrl>
</Style>
<Model>
<altitudeMode>absolute</altitudeMode>
<Location>
<latitude>36.08260761307279</latitude>
<longitude>-112.2552505069063</longitude>
<altitude>0</altitude>
</Location>
<Orientation>
<heading>0</heading>
<tilt>0</tilt>
<roll>0.0</roll>
</Orientation>
<Link>
<href>models/LinearSpline.dae</href>
</Link>
</Model>
</Placemark>
</Folder>
</kml>

LinearSpline.dae:

<?xml version=“1.0” encoding=“utf-8”?>
<COLLADA xmlns=“http://www.collada.org/2005/11/COLLADASchema” version=“1.4.1”>
<asset>
<contributor>
<author>Sphere</author>
<authoring_tool>Google SketchUp 6.4.112</authoring_tool>
</contributor>
<created>2008-05-28T18:03:11Z</created>
<modified>2008-05-28T18:03:11Z</modified>
<unit name=“inches” meter=“0.0254”/>

<up_axis>Z_UP</up_axis>
</asset>
<library_geometries>
<geometry id=“spline” name=“spline”>
<spline closed=“false”>
<source id=“positions”>
<float_array id=“positions-array” count=“12”>
-112.2552505069063,36.08260761307279,2357
-112.2564540158376,36.08395660588506,2357
-112.2568540158388,36.08395660588506,2357
-112.2552505069063,36.08260761307279,2357
</float_array>
<technique_common>
<accessor source="#positions-array" count=“4” stride=“3”>
<param name=“X” type=“float”/>
<param name=“Y” type=“float”/>
<param name=“Z” type=“float”/>
</accessor>
</technique_common>
</source>
<source id=“interpolations”>
<Name_array id=“interpolations-array” count=“4”>
LINEAR LINEAR LINEAR LINEAR
</Name_array>
<technique_common>
<accessor source="#interpolations-array" count=“4” stride=“1”>
<param name=“INTERPOLATION” type=“Name”/>
</accessor>
</technique_common>
</source>
<control_vertices>
<input semantic=“POSITION” source = “#positions”/>
<input semantic=“INTERPOLATION” source="#interpolations"/>
</control_vertices>
<vertices id=“spline-vertex”>
<input semantic=“POSITION” source="#spline"/>
</vertices>
</spline>
</geometry>
</library_geometries>
<library_cameras>
<camera id=“Camera-camera” name=“Camera-camera”>
<optics>
<technique_common>
<perspective>
<xfov>46.666667</xfov>
<yfov>35.000000</yfov>
<znear>1.000000</znear>
<zfar>1000.000000</zfar>
</perspective>
</technique_common>
</optics>
</camera>
</library_cameras>
<library_visual_scenes>
<visual_scene id=“SketchUpScene” name=“SketchUpScene”>
<node id=“Model” name=“Model”>
<node id=“position” name=“position”>
<instance_geometry url="#spline">
</instance_geometry>
</node>
<node id=“Spline” name=“Spline”>
<instance_geometry url="#interpolations">
</instance_geometry>
</node>
</node>
<node id=“Camera” name=“Camera”>
<matrix>
0.848819 -0.139169 0.510038 539.801860
0.528684 0.223440 -0.818882 -535.307595
0.000000 0.964731 0.263237 328.919934
0.000000 0.000000 0.000000 1.000000
</matrix>
<instance_camera url="#Camera-camera"/>
</node>
</visual_scene>
</library_visual_scenes>
<scene>
<instance_visual_scene url="#SketchUpScene"/>
</scene>
</COLLADA>

Hi Sphere

Google Earth doesn’t support true spline curves. You will have to approximate your spline with straight line segments.

Best Regards
Bryce Stout
Product Manager
Google