Opacity mask experiment

So I was thinking earlier, When you create an opacity mask in UDK at what point does the mask decide whether to render a pixel or not? So to find this out I did an experiment. =D

When I create a opacity mask it usually goes into the alpha channel on the diffuse, spec or normal of that texture, meaning the texture is saved as a 32bit TGA, but in that alpha channel I can have a gradient from black to white which could essentially be my spec. so to find out what range I could get I created a gradient texture and plugged it into the opacity mask in UDK.

 

 

Turns out the range on UDK to mask something kicks in at R,G,B: 158, giving you a fair bit of gradient that would otherwise go wasted

Now if some clever sod could figure out a way to change this so that instead of R,G,B: 158 it could mask at R,G,B: 0 or 1 then you would have an even larger gradient to use.