Model Movement

Making a model move can be a powerful visual in Google Earth. Creating the KML file requires a little legwork, but once you have a process, it is a pretty fast tour to build. 

Here is what you need to know about model a moving:

1. Have a template file - Using a template file is going to make the whole process easier. You will plug in a few variables and the template file will do the rest. Editing the file is most easily done in a text editor, like SciTE (PC) or Text Wrangler (MAC). These are both free. A template file is attached to the bottom of this page.

2. You'll need three things for your template file - To build your tour, put the following information into the template file: 

• • the model file and location on your computer

  • camera location(s)

  • model start and end location

3.The model - Find a model on wither the 3D Warehouse or create one using a program like SketchUp.

• It's best to keep the model size manageable, like 2 MB or smaller.

• You will reference the model location on your computer in the KML template file. This locations is like C:/Users/JohnDoe/Desktop/Projects/airplane.dae

• The file has to be a .DAE This can be downloaded from the 3D Warehouse, or extracted from a KMZ. 

• The size and rotation are easily set in the KML template file

4. The camera position at the views that you want to use - Set a Placemark where you want the camera to look.

• If you want the camera to move at all, you should set a couple Placemarks where you want the camera to start and end. 

• Moving the camera a lot can be confusing for viewers. Small, simple movements have the best effect. 

5. The Latitude / Longitude of the model start and end location - you can do this by dropping a Placemark and looking at the Lat/Long numbers. This value is the location of the Placemark icon (the yellow thumbtack).

6. The KML file - This is what the full KML looks like. It's fewer than 100 lines, so a easily readable file. 

• Notes are added in yellow and look like this <!-- notes --> These will not affect the way the file works and are to help understand the KML function. 

• This file does not have the camera moving

• You can copy the code below and paste it into a text editor, save it as a KML and use it. 

• Stuff you'll want to edit is in yellow.

<?xml version="1.0" encoding="UTF-8"?>

<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">

<Document>    

 <!-- give the tour a name here -->

 <name> (tour name) </name>  

    <open>1</open>  

    <description><![CDATA[

        If you can read this, your KML opened

    ]]></description>

<!-- camera location -->

    <LookAt>

<longitude>00.000000</longitude>

<latitude>00.000000</latitude>

<altitude>00.000000</altitude>

<heading>00.000000</heading>

<tilt>00.000000</tilt>

<range>00.000000</range>

<gx:altitudeMode>relativeToSeaFloor</gx:altitudeMode>

    </LookAt>

<gx:Tour>

    <name>Click here to start</name>

    <open>1</open>

        <gx:Playlist>

<gx:Wait><gx:duration>1</gx:duration></gx:Wait>

<gx:AnimatedUpdate>

<!-- length of model movement action, here it's 2 seconds -->

    <gx:duration>2</gx:duration>

        <Update>

    <targetHref></targetHref>

        <Change>

                <Placemark targetId="model">

    <Model>

<Location>

                            <!-- model END lat/long -->

                 <longitude>00.000000</longitude>

    <latitude>00.000000</latitude>

</Location>

    </Model>

</Placemark>

</Change>

</Update>

</gx:AnimatedUpdate>

<!-- must be equal or greater than length of model movement action above (2 seconds) -->

<gx:Wait><gx:duration>3</gx:duration></gx:Wait>

</gx:Playlist>

    </gx:Tour>

<Placemark id="model">

<name>model</name>

<Model Id="model">

<Location>

<!-- model START lat/long -->

    <longitude>00.000000</longitude>

    <latitude>00.000000</latitude>

</Location>

<!-- model heading, change this to align with your movement -->

<Orientation>

             <heading>80</heading>

    <tilt>0</tilt>

    <roll>0</roll>

</Orientation>

<!-- model scale, change to make the model larger -->

<Scale>

    <x>1</x>

    <y>1</y>

    <z>1</z>

</Scale>

<!-- model file location on your computer -->

<Link>

    <href>C:/Users/etc/etc/etc</href>

</Link>

</Model>

</Placemark>

 </Document>

</kml>

6. Save the file and test - Save the file as a .KML and open it in Google Earth. 

• • If you get an error, your text editor may tell you what line the error is on. This will help find problems

  • Small things like forgetting a greater-than or less-than sign will cause the KML to fail. 

• <gx:duration>2 /gx:duration>   PROBLEM!

7. Practice a bit with just the model moving - Once you have that down, you can easily add in the camera moving. 

Notes are added in yellow and look like this <!-- notes --> These will not affect the way the file works and are to help understand the KML function. You can copy the code below and paste it into a text editor, save it as a KML and use it. Stuff you'll want to edit is in yellow.

<?xml version="1.0" encoding="UTF-8"?>

<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">

  <Document>    

 <!-- give the tour a name here -->

 <name> (tour name) </name>  

    <open>1</open>  

    <description><![CDATA[

    If you can read this, your KML opened

    ]]></description>

<!-- camera start location -->

    <LookAt>

<longitude>00.000000</longitude>

<latitude>00.000000</latitude>

<altitude>00.000000</altitude>

<heading>00.000000</heading>

<tilt>00.000000</tilt>

<range>00.000000</range>

<gx:altitudeMode>relativeToSeaFloor</gx:altitudeMode>

    </LookAt>

<gx:Tour>

    <name>Click here to start</name>

    <open>1</open>

        <gx:Playlist>

<gx:Wait><gx:duration>1</gx:duration></gx:Wait>

<gx:AnimatedUpdate>

<!-- length of model movement action -->

    <gx:duration>2</gx:duration>

        <Update>

    <targetHref></targetHref>

        <Change>

                <Placemark targetId="model">

    <Model>

<Location>

                            <!-- model END lat/long -->

                 <longitude>00.000000</longitude>

    <latitude>00.000000</latitude>

</Location>

    </Model>

</Placemark>

</Change>

</Update>

</gx:AnimatedUpdate>

<!-- camera end location -->

    <gx:FlyTo>

        <!-- this is how fast the camera will move (10 seconds). The value must be equal or greater than length of model movement action above -->

<gx:duration>10</gx:duration>

<gx:flyToMode>smooth</gx:flyToMode>

            <LookAt>

         <longitude>00.000000</longitude>

        <latitude>00.000000</latitude>

         <altitude>00.000000</altitude>

         <heading>00.000000</heading>

         <tilt>00.000000</tilt>

         <range>00.000000</range>

        <gx:altitudeMode>relativeToSeaFloor</gx:altitudeMode>

        </LookAt>

    </gx:FlyTo>

</gx:Playlist>

    </gx:Tour>

<Placemark id="model">

<name>model</name>

<Model Id="model">

<Location>

<!-- model START lat/long -->

    <longitude>00.000000</longitude>

    <latitude>00.000000</latitude>

</Location>

<!-- model heading, change this to align with your movement, a bit of guess and check -->

<Orientation>

             <heading>80</heading>

    <tilt>0</tilt>

    <roll>0</roll>

</Orientation>

<!-- change the model scale -->

<Scale>

    <x>1</x>

    <y>1</y>

    <z>1</z>

</Scale>

<!-- model file location on your computer -->

<Link>

    <href>C:/Users/etc/etc/etc</href>

</Link>

</Model>

</Placemark>

 </Document>

</kml>

8. Additional edits you can make - Many of the variables can be added to the <gx:AnimatedUpdate> tag and changed in the tour. 

...........

<gx:AnimatedUpdate>

<!-- length of model movement action -->

    <gx:duration>2</gx:duration>

        <Update>

    <targetHref></targetHref>

        <Change>

                <Placemark targetId="model">

    <Model Id="model">

<Location>

                            <!-- model END lat/long -->

                 <longitude>00.000000</longitude>

    <latitude>00.000000</latitude>

</Location>

                        <!-- model END heading -->

         <Orientation>

                     <heading>80</heading>

            <tilt>0</tilt>

            <roll>0</roll>

        </Orientation>

        <Scale>

                        <!-- model END scale-->

            <x>1</x>

            <y>1</y>

            <z>1</z>

        </Scale>

                 </Model>

        </Placemark>

                </Change>

</Update>

</gx:AnimatedUpdate>

..............

Some considerations:

• • All changes in one animated update will happen at the same time

  • You can add additional </gx:AnimatedUpdate> actions by duplicating everything above, for example if you wanted the plane to fly to a location, then change heading. 

• • Any additional </gx:AnimatedUpdate> tags must be given time to complete in the <gx:duration>2</gx:duration> of the last <gx:Wait> or <gx:FlyTo> tag. 

  • If the <gx:duration> in the </gx:AnimatedUpdate> tag is shorter than the <gx:duration> in the last <gx:Wait> or <gx:FlyTo> tag, then the action will not have time to complete:

final <gx:duration> too short

• If you want to save the file and share it, you'll want to do so by saving it as a KMZ from Google Earth. This will wrap up the model and KML file into one package and simplify sharing

• If you fail to have the model ID defined in the <Placemark>, it will not allow you to save the KML as a KMZ. 

  • Instead of just <Model> , it needs to be <Model Id="model"> . 

  • The name of the model ID doesn't matter as this KML doesn't call for it, it addresses the Placemark by the <Placemark targetId="model">.

  • It doesn't need to be defined in the <gx:Tour>, only in the <Placemark> .

  • If you're going to give the model visibility, the <visibility>0</visibility> tags must be within the <Model> tags, otherwise you will get an error when trying to save the KMZ

• Save and test often, it will be easier to find mistakes if you only have to look back a few changes.