//action: fx_terraintex3
//title: 3-Textures Terrain 
//
//skill2: ScaleSkin2 15
//help: Skin2 base texture scale, 1..50, default 15.
//skill3: ScaleSkin3 15
//help: Skin3 red texture scale, 1..50, default 15.
//skill4: ScaleSkin4 15
//help: Skin4 green texture scale, 1..50, default 15.
//desc:
/// Blends 3 textures together, according to
/// the red and green channel in the first skin.
/// The blue channel can be used for a shadow map. 
/// Skin1 = Terrain RGB blend & shadow mask.
/// Skin2 = Base tiled terrain texture (grass).
/// Skin3 = Red channel masked tiled texture (sand).
/// Skin4 = Green channel masked tiled texture (rock).
/// Skin5 = Optional base texture for non-shader hardware.
/// Skin6 = Optional detail texture for non-shader hardware.
//
//Based on ideas by Thomas 'ventilator' Oppl
//and Eric 'Steempipe' Hendrickson-Lambert
//