fgdata/Materials/dds/materials.xml

<?xml version="1.0"?>
<!-- FlightGear Materials File. See Docs/README.materials for details. -->

<PropertyList>

 <!-- Shared parameters for various materials. -->
<params>
  <forest>
    <!-- Maximum distance from which all trees are visible. -->
    <!-- Some trees will be visible to twice this range  -->
    <tree-range-m>8000</tree-range-m>
  </forest>
  <building>
    <!-- Maximum distance from which all buildings are visible -->
    <!-- Some buildings will be visible to twice this range. -->
    <building-range-m>10000</building-range-m>
  </building>
</params>

<!-- Base materials -->
<region include="Materials/dds/global.xml"/>
<region include="Materials/dds/global-summer.xml"/>
<region include="Materials/dds/global-winter.xml"/>

<!-- Urban shader -->
<region include="Materials/dds/urban.xml"/>

</PropertyList>