It seems mask fail when you look at them laterally. Is this a issue?
I am trying to colour fake stones, which when using the colour options changes the shapes because it uses said colours as a mask it seems when plugged into a child of a surface layer (darker the colour, the more the layer below shows). So I kept them bright white, and then used them as a mask to colour them.
At close range looking down at them it works fine, 100% of the rocks are covered, however at a distance, the mask seems to fail the more you look at it from the side.
(http://i.imgur.com/bcZ0vAw.png)
Using the stones for their own mask would never work perfectly if the stones bulge sideways across the boundaries of their (vertical) mask, I'd say.
So there is no way to colour stones 100% precisely? They don't colour themselves correctly, nor does a surface shader, and neither does masking in the colour? :\
This has always been a issue hat lead me to use the rock population. For sand and gravel or far away scenes the colour issue isn't much of a issue but I'm trying to do a close up mossy scene.
This might be solution. Don't know though.
http://www.planetside.co.uk/forums/index.php/topic,18068.msg175212.html#msg175212
That's how its setup. Rocks and surface shader create solid white on high settings. After that is another surface layer using that mask.
No offense too I don't buy verticals being a issue. You can mask an entire mountain with a flat mask.