Jim Wilson:

Jim Wilson:

This patch adds support to the model animation system for modifying emissive
states on the fly so that it is possible to make "lights" appear to dimm.

This is an example of a configuration entry which should explain how it is used:

 <animation>
  <type>material-emission</type>
  <object-name>Face</object-name>
  <property>/controls/lighting/instruments-norm</property>
  <emiss-red>1.0</emiss-red>
  <emiss-green>0.8</emiss-green>
  <emiss-blue>0.5</emiss-blue>
 </animation>

Note the color entries are the emissive colors when the "property" value is
1.0.  They are useful for tinting the light.   The "property" itself must be
float or double and is clamped to values between 0 ~ 1.0 inclusively.   The
"property" value is multiplied against the colors to get the actual material
properties.  Thus property value 0.0 = darkest, and 1.0 = brightest.