This is the final result of this tutorial (rendered, obviously):
So let's get right into it!
Begin by clicking the big Shaders button on the toolbar at the top.
In the outline, you'll see something that says Base colours. This is, as it states, the base color of our landscape; it's the color that's being displayed when we render our scene. Some people use it, and some don't. In this case, I won't; click on Add Layer and choose Surface Layer from the menu.
In the 3D viewport, your whole landscape will be shrouded in white. Or at least, it looks like white; it's actually just a light gray. We're going to make this layer our dirt (every landscape should have at least a tiny bit of dirt; it looks more natural), so name it dirt in the box next to the word Name.
Next, choose a color for your layer by selecting the box with the gray color in it, and changing it to a dark brown.
Now click on the + button next to the Color Function box, and go to Create New Shader - Color Shader - Power Fractal v3. This will add color variation, and break up the dirt a little more to make it look a lot more realistic.
Now that the dirt's done, we can add on another surface layer; so let's do that. Add another Surface Layer, and name it Grass. Select a green color in the color box, and give your grass a Power Fractal v3 shader as well.
But there are two problems here; one is, we want to be able to see some of our dirt poking through the grass (I know it sounds like it should be the other way around, but I know what I'm doing :D), so go to the Effects tab in the properties panel, and enable Intersect Underlying.
If we take a look at our 3D Preview window, we should see something like this:
As you can see, the dirt is breaking through the grass based on slope angles; this is especially handy when creating a snow-capped mountain (or even just a mountain completely covered in snow) and you want the rock underneath to poke through.
Let's add another Surface Layer; name it Rock, and select a dark grey color from the color box. Give this one a power fractal shader as well. You'll notice that the rock is covering the entire mountain, but we only want it to cover a certain portion of it, and starting at a certain point in elevation. This can be fixed by going into Altitude Constraints and selecting Limit Minimum Altitude.
The Minimum altitude determines what height we should limit the rock to, and the Min alt fuzzy zone is what controls how sharply we want the grass and the rock to blend together. In my case, the defaults work fine (surprise, surprise! That's a first :D), but you may need to tweak the altitude a little bit until you're happy with it.
As you can see, the rock now only starts at a certain altitude, instead of covering the entire mountain. I'm going to add a snow layer on top, but I won't describe everything I do with it, as I'll be using the Intersect Underlying option and the Limit Minimum Altitude as well, and I just covered these two aspects.
And that's all! I hope you enjoyed this tutorial, and if you have any questions, comments, or encountered any problems while following this tutorial, post them in the comments below or send me an email at firstname.lastname@example.org. Thanks for reading!