And here is how to evaluate the slope of a surface with the n-node, to limit any snow/dust/foam to more horizontal areas and suppress the layer in more vertical areas.

Poser Pro 2014 GameDev, Lightwave 11.6.3, Blacksmith3D Pro 6, Bryce 7, Carrara Pro 8.5, Reality 4 & LuxRender, Python 2.7 & Wx-Python, UV-Mapper Pro, XFrog 3.5, Paintshop Pro X7, Apophysis 7x64

-  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -

Don't render faster than your artistic guardian angel can fly...