Terragen 2 is a landscape generator, and it produces extremely realistic results. If you take a quick look at my CG Artwork section on this blog, you'll see a few landscapes that I have made using this program.
Terragen 2 has both a pro version and a free version, and in this tutorial I will be using the free version. The restrictions in the free edition are:
1.) You can't use any of what you make for commercial purposes
2.) Your maximum render size is 800 by 600
3.) You have a limitation on detail amounts and anti-aliasing
4.) You can't use more than 3 object populations (we'll go into that later)
5.) You can't animate (it would take forever to render an animation anyway. A 5 minute animation could take up to a year to render, depending on the quality and size)
You may think these are all horrible restrictions, but I can't afford the pro edition, and I still enjoy using the free.
I know this isn't related to blender at all, but blender tutorials will still be released, it's not the end of the world (not that I get a ton of page views, anyway), and this is, after all, free software.
It can be downloaded here. I also strongly recommend you download the two additional plant packs at the bottom, as those are incredibly helpful at times (as land does tend to look a little better with some form of foliage covering it). While you're at the site, take a look at the gallery; believe me, you won't regret it :D
Assuming that you have installed Terragen 2, let's get started! Open it up, and a little splash screen will pop up. Unless you want to buy the software, click on Use Free Edition (obviously :P)
As you can see, the interface looks a bit complex at first (maybe not quite as complex as blender looked when you first opened it, though ;), but it doesn't take long to get used to it. I learned how to use Terragen 2 in about 7 hours (not straight, though) simply by messing around and looking at other tutorials for it. Let's start with the interface now:
As you can see, there are 5 main sections in the interface.
1.) 3D Viewport - This is where you can see the product of your work; the aspects that are displayed in it vary depending on what you're doing to the landscape
2.) Node Configuration - I'm sure you've heard of Blender's compositing nodes by now (unless you've never used blender before); and it's other nodes: materials and textures. This is similar in a way, except that this time, the nodes control the entire scene. As you can see, it has multiple different categories in it: Atmosphere, Cameras, Lighting, Objects, Renderers, Shaders, Terrain, and Water. There are several nodes that can be used to control those specific elements. Of course, a lot of things you can do with the nodes, you can do in the properties panel on the left. But there are some advantages to the node set up, and we'll delve into these later.
3.) Properties - This is where most of the magic is; the properties panel is what you use to do almost anything to your landscape.
4.) Outliner - The outliner is exactly the same as it is in Blender; it simply displays a list of everything involved in your scene, with a small amount of interactivity.
5.) Toolbar - Whatever option you choose on the toolbar will display its properties in the Properties window, as covered above.
Of course, there are multiple other options in Terragen 2, but these were the major parts of it.
Let's move on to the navigation controls. The main one you'll want to know is rotating your view. This is done by dragging your middle mouse button, just like you'd do in blender to achieve the same effect. You can also zoom out, but it's actually reverse; when you scroll your mouse wheel in, you zoom out, and vice versa. These a re the only two shortcuts I use, as I rely on the navigation panel for the rest of it. This is located in the upper right corner of your 3D viewport:
As you've probably noticed, these controls are fairly straightforward, so I don't need to go into too much detail on them.
Another thing is, if you move your view around a little, and like the new position, you need to copy the location to the current render camera. If you don't press this button, when you render, it will render the position you were originally in before moving, so be sure to press that button.
And that's it for the interface! I hope you enjoyed this quick little tutorial, and I'll be releasing one on how to generate an actual landscape next (probably within the next hour or so). Thanks for reading!