Did you try what I mentioned previously? Apply the transparency of the diffuse to the specular layer, then add. That should retain the transparency.
I haven't used the mia_material_x_passes yet, I'll do that tomorrow along with what Gen suggested about extruding the glass.
If you mean use the alpha of the diffuse as a mask, I'd still end up with this, which cuts out the specular that I need at the top side of the hourglass.
I could combine both of these and form a new mask but I'd still end up with the glass turning black and there's nothing I can do about that one (see below).
Yep just mask off the black background.
It leaves me with this. The black still keeps holding on to the specular layer after using Add.
Last edited by SilverFeather; 27-06-2015 at 12:14 AM.