I think I understand the problem, but I don’t know how to fix it. On my terrain, I have canyons. They are exactly what they sound like: deep ravines with sheer walls. When I texture the wals of the canyons, the texture is distorted, meaning, the texture being used for the walls has horizontal lines, when the texture is put on the walls, the lines are not horizontal. They run more at something like a 50 - 60 degree angle.
I suspect this is a matter of the vertices in the terrain being too few, so, because the cliff faces are so high, the texture is being stretched upwards. If I am right, then how do I fix the problem? If I am wrong, does anyone know what the problem might be?
It is not possible to do what you want with the terrain. The terrain is unwrapped as a planar object, and whenever you raise a part of it, the texture will get stretched. The only real solution to that, is making the walls as separate properly unwrapped objects, and the blending them into the terrain. I have done so myself with fine results.
Which would be fine for small areas, but if a large area of canyons is used, creating meshes for the walls becomes prohibitively time consuming. Is it possible to create a mesh out of the terrain? I think I read that somewhere. If that is possible, that would save a lot of time.