fgdata/Aircraft/Instruments-3d/comp/comp.xml

<?xml version="1.0"?>

<PropertyList>

 <path>comp.ac</path>

 <animation>
  <type>material</type>
  <object-name>Ring</object-name>
  <emission>
   <red>1.0</red>
   <green>0.2</green>
   <blue>0.0</blue>
   <factor-prop>/sim/model//material/instruments/factor</factor-prop>
  </emission>
 </animation>

 <animation>
  <type>rotate</type>
  <object-name>Ring</object-name>
  <property>/instrumentation/magnetic-compass/indicated-heading-deg</property>
  <axis>
   <x>0.0</x>
   <y>0.0</y>
   <z>1.0</z>
  </axis>
 </animation>

</PropertyList>