Is it possible to do slope-based shaders in Carrara? Like on a terrain, to have grass on the level areas and a rock-face on the steep slopes and cliffs, or on a skyscraper, a window texture on the vertical surfaces and a solid grey or black color on the horizontal surfaces. (excuse my newby-ish questions onnthis, I'm still waiting for my copy of the Carrara 5 Pro handbook to be delivered).

The terrain distribution shader is quite capable of this and much more.

Additionally, there is a slope shader function that youcan use as a mixer in the shader tree.