$burning
... 
$burning is a material shader parameter available in the 
and 
. It covers the $basetexture with a $burndetailtexture, to give the illusion that the model has been injured by fire. It does this by switching the clean version of the texture to a different .vmt with a "_burning" prefix, which slowly increases the opacity of the $burndetailtexture up to 100%.
Todo: Check for more games that have $burning.
Syntax
$burning <bool>
