osgearth cache

<map name="readymap.org" type="geocentric">
    <options>
        <!--Specify where to cache the data-->
        <cache type="filesystem">
            <path>cache</path>
        </cache>
    </options>
    <image name="readymap_imagery" driver="tms">
        <url>http://readymap.org/readymap/tiles/1.0.0/7/</url>
    </image>

    <elevation name="readymap_elevation" driver="tms">
        <url>http://readymap.org/readymap/tiles/1.0.0/116/</url>
    </elevation>
</map>