Set line width in COLLADA for viewing in Google Earth

I can set up 3D lines in a COLLADA .dae file and view them in Google Earth, but they are really thin and very hard to see over Colorado. How can I set the line width to something other than the default of 1 (meter?)? I have located the line_width tag in the COLLADA documentation, but it does not seem to do anything no matter where I put it.

Here is my .dae file Lines-blue.dae.

<?xml version="1.0"?>
<COLLADA xmlns="" version="1.4.1">
      <author>Carl Drews</author>
      <authoring_tool>Assimp Collada Exporter</authoring_tool>
    <unit name="meter" meter="1" />
    <effect id="m0DefaultMaterial-fx" name="m0DefaultMaterial">
        <technique sid="standard">
              <color sid="emission">0   0   0   1</color>
              <color sid="ambient">0.05   0.05   0.05   1</color>
              <color sid="diffuse">0   0   1   1</color>
              <color sid="specular">0   0   0   1</color>
              <float sid="shininess">16</float>
              <color sid="reflective">0   0   0   0</color>
               <float sid="transparency">0.5</float>
          <technique profile="GOOGLEEARTH">
    <material id="m0DefaultMaterial" name="m0DefaultMaterial">
      <instance_effect url="#m0DefaultMaterial-fx"/>
    <geometry id="meshId0" name="meshId0_name" >
        <source id="meshId0-positions" name="meshId0-positions">
          <float_array id="meshId0-positions-array" count="36">
		  0 0 0
		  12000 0 0
		  6000 6000 6000
		  12000 0 0
		  12000 12000 0
		  6000 6000 6000
		  12000 12000 0
		  0 12000 0
		  6000 6000 6000
		  0 12000 0
		  0 0 0
		  6000 6000 6000
            <accessor count="12" offset="0" source="#meshId0-positions-array" stride="3">
              <param name="X" type="float" />
              <param name="Y" type="float" />
              <param name="Z" type="float" />
        <source id="meshId0-normals" name="meshId0-normals">
          <float_array id="meshId0-normals-array" count="36">
		  0 -0.5 0.5
		  0 -0.5 0.5
		  0 -0.5 0.5
		  -0.5 0 0.5
		  -0.5 0 0.5
		  -0.5 0 0.5
		  0 0.5 0.5
		  0 0.5 0.5
		  0 0.5 0.5
		  -0.5 0 0.5
		  -0.5 0 0.5
		  -0.5 0 0.5
            <accessor count="12" offset="0" source="#meshId0-normals-array" stride="3">
              <param name="X" type="float" />
              <param name="Y" type="float" />
              <param name="Z" type="float" />
        <vertices id="meshId0-vertices">
          <input semantic="POSITION" source="#meshId0-positions" />
          <input semantic="NORMAL" source="#meshId0-normals" />
        <lines count="4" material="theresonlyone">
          <input offset="0" semantic="VERTEX" source="#meshId0-vertices" />
          <vcount>3 3 3 3</vcount>
          <p>0 1 2
		  3 4 5
		  6 7 8
		  9 10 11
    <visual_scene id="myScene" name="myScene">
      <node id="STL_BINARY" name="STL_BINARY">
        <matrix>1 0 0 0
		        0 1 0 0
				0 0 1 0
				0 0 0 1</matrix>
        <instance_geometry url="#meshId0">
              <instance_material symbol="theresonlyone" target="#m0DefaultMaterial"/>
    <instance_visual_scene url="#myScene" />

Here is the KML fragment that includes the COLLADA Model:

<Style id="WideLine">

  <name>Experimental white lines floating over Boulder.</name>
  <description>Model created by Carl Drews - November 18, 2022.</description>

    <latitude> 40.0650</latitude>

  <Style id="default">

  <Model id="model_7">
      <latitude> 39.7000</latitude>

These lines in 3D space are supposed to trace the contours of 3D isosurfaces that I have already created with COLLADA and displayed with Google Earth. But the lines won’t show up unless they are thicker or wider. I could create lines in pure KML (no .dae) but I don’t think they will lay down on my isosurfaces accurately enough.

Thank you for any assistance you can provide.

Here is a screen shot to clarify. The thin blue lines run from roughly Glendale to Buckley AFB and then on to Rocky Mountain Arsenal.

Hmm, I don’t know a lot about COLLADA and Google Earth (GE), but it looks like you are using a GE specific extension for the line width - assuming that is the way to do that it feels like a bug in the GE renderer. Line width is often specified in pixels, have you tried some values in the 1-10 range?
Also, KML has support for line width (no idea if it works though :wink: ) - can you use that instead of COLLADA?