This is kind of hard to explain… With terrain, you could ‘spray’ on new textures, so that the rocks and the grass looked nice together and blended well, I just got rid of my terrain in order to make a cave, as well as make the cliffs sharper, and drastically reduce the polygon count. However now my textures are very linear, it’s obvious when one begins and the other ends, and as a result makes the map look ugly, I need some help with making the textures blend into each other.
theres an opacity setting, and a target setting adjusting these will make the texture appear fainter… then when you want to blend to textures, just lower the opacity to around 60 or 70 percent and draw over them, just like blending colours with pastels.
http://docs.unity3d.com/Documentation/Components/terrain-Textures.html