ok, now I see.. Select mask render, render the image and save as you want ( .bmp ). Then, in Photoshop, load the render and the mask render image. Then convert the normal image as a layer ( 2 clicks on it ). Select the normal image layer and add a mask to it. Copy the mask render image on the normal image layer ( mask must be selected ) and now you have full transparency features... if you understood what I meant :) Sorry, this Photoshop is in french...