I think the Wilderness tutorial uses the fake stones shader, not rock objects.
The 'rock' is a very good item to have and use but, not always for rocks!
The benefits are that; rocks can make better spheres than the default sphere(couple of thousand faces and smooth normals), rocks can be raytrace rendered, they can be rescaled on
any axis and, rocks can be populated!
Once you add a rock object, Terragen assumes that you will be texturing it yourself with some nice rock shaders that you have elswhere in the node network or, have yet to create. You begin with a basic, grey 'default shader' that's in the internal network of the rock, keep this shader there, you'll want to use it later...
Before doing any work to the surface shaders for your stone, make a couple of changes to the actual object geometry first;
This is a default rock:
[attachimg=#]
Not pretty.
So, firstly and quite importantly, in my opinion, is to check 'use smooth normals'. Now, hopefully, the rock looks a
little more rock-like(not so many completely flat faces/sharp angles, at any rate).
[attachimg=#]
Next, I always add at least an extra '0' to the 'number of faces'. Now we're talking, 200 faces is far better than the default 20.
[attachimg=#]
Looks better already.
Next, I'd concentrate on the colouring. The reason I said to keep the default shader is so you can use all the input channels that your rock's 'default shader' includes, if you need them. I used 4 power fractals, I also
uncheck 'apply displacement' in these, it isn't required and you'll want your shader preview windows to only preview your colour. Set the final fractal to the 'colour function' of the default shader, use the slider to adjust brightness. A value of '1' will apply the level of colouring that the previous fractals output, higher or lower lightens/darkens this, respectively.
With colour:
[attachimg=#]
Now, set any of your fractals(probably your last one) as the 'displacement function' of the main 'default shader', adjust 'displacement amplitude' until you find the right level of bumping to match your rock features.
My rock now looks like this with displacement added:
[attachimg=#]
Finally, I'll make a new, small scaled(0.01 fixed scale), high colour only fractal(you could also just use one higher up the colour chain, whatever suits) reduce its colour offset from about -0.25 to -1 and set this as the 'reflectivity function' of the default shader. Set specular to '1'. This will apply some shiny patches/spots to the surface.
My final rock now looks like this:
[attachimg=#]
The rock object is a fantastic piece of TG2, many people avoid it. Please don't, use some creativity and you can make many things from it.
Make sure to check 'Ray trace objects' in the renderer, you won't be able to apply displacement otherwise. Select either 'individual object' or member of a population' after you've created your surfacing, it's more difficult to create a rock from the population method(because it is invisible) than it is to make a single object and change its mode afterwards.
Also, not really rock-like but, I like to show this image when I see people struggling or bemoaning the 'good-for-nothing rock object'.
The 'craft' is almost completely made out of rocks...
http://forums.planetside.co.uk/index.php?topic=5312.msg54811#msg54811
