I have a problem that I'm trying to solve for about 2 days.
I have a globe with the earth map mapped into it. I'm working with Cycles so I have a alpha map defining that the ocean is transparent and the land is opaque.
However, I want the land to be a somewhat transparent too. I could do this in the alpha map. The problem is that when the land starts to overlay with the one on the back side of the globe, I get too much multiply effect on the color.
My solution was to make the alpha map so that the ocean is transparent and the continents opaque. Then I would put all the layer opacity down, maintaining this way the transparency made by the alpha map but just getting it all down in the same proportion.
Is there a easy way to do this or is it even possible? Here's a image of my node editor on my globe: