This is the process by which we combine two texture layers to correctly map a flat texture to vertical surfaces such as mountains and cliff faces. Some 3D engines can have some kind of vertical mapping built into a pixel shader which is very handy when available. However, we can't always rely on this; for our project we can assume the mobile platforms will require baked textures with correctly mapped vertical surfaces. We can create two layers to achieve accurate vertical mapping in the following manner:
arid2/canyon_rock01.tgatexture as provided in the GROME texture library).