onedotone:: fixed alpha problem. added standard gain and bias. (will not work with old maya scenes)

the mix8layer acts like your layer system in photoshop.. there're all the same blending modes (plus some others).. hvs functions and color corrections.. local and global (for the specif layer or for the whole shader).. opacity strenght, color and alpha inversion... alpha channels.. clipping methods.. to use with mentalray.

for Maya and XSI.