I have added a few more V steps, tweaked the shape and applied Reshape>Disrupt to randomize the surface a little. For interest's sake I've also added a ground plane, which is a mesh displaced with a greyscale map using Reshape>Displace. The Subdivision of Rock_wall I set to 10 in both the U and V fields. This will give us a surface detailed enough to displace well at render time. Don't sweat the details, this model is just a stand-in to build our Shader on.

When you are satisfied with your model select File>Save and name the file Rock Shader Tutorial.

With the Rock_Wall model selected hit Command-w to open the Shader Manager. Click on an empty space in the pallet to create a new Shader and open the ShaderMaker dialogue.