I've seen several terrain shader topics posted as well as the shaders on the community wiki - yet I've been unable to apply them to a generated terrain. The closest thing I've found was this topic http://forum.unity3d.com/viewtopic.php?t=8617 Yet when I try and "sub out" the shader code I want to use with the built in shader code, nothing appears to happen. Am I going down the wrong path in thinking I can apply, say the 4 Layer shader from the wiki to a terrain which was generated inside Unity? Or must I export the terrain and then apply the shader thus loosing the trees and grass? Thanks!
The shaders for built-in terrain can't be changed, at least currently. The shaders on the wiki are for custom terrain-like objects. In case of layered shader, for example, the buil-in terrain already has that functionality - you paint multiple textures and they appear on the terrain.