RVMAT – ArmA: Armed Assault Talk

Additional Info (from Armored_Sheep)

 Specular map is a complex bitmap. Each color chanel has its own purpose. 
 You should understand well the way of calculating pixel colors in scene
 before you paint those textures. As written value of each pixel is
 calculated with RVMAT values and engine lighting values. Texture _SM has
 diffuse values in RED, specular in GREEN and, Specular power in BLUE
 chanel. _SMDI does not use RED chanel (better compression) GPU calculates
 those values automaticaly as Diffuse = 1 - Specular. When you use
 specular map - diffuse, specular in RVMAT should be 1. Then paint B/W map
 with maximum specular and minimum specular values you imagine on surface.
 Than choose minimum (black) and maximum specular (white) values and change
 the bitmap levels to those values. (c)Armored_Sheep

--Bdfy