Previous Chapter: Getting Set Up
Now you’ve got Blender and your heightmap, and so we’re ready to get started. First we’re just going to familiarize ourselves with some of the basics of how to get around the software. As I mentioned, this is a big, powerful, 3D modeling program, and we’re only going to use a tiny portion of its features. I’m going to skip over a lot of the different buttons that aren’t relevant to doing shaded relief — I’m no expert, so I don’t even know what many of them do. Probably some interesting stuff in there, though, so if you figure out an interesting cartographic use for some of the software’s other features, I’d love to hear it. Meanwhile, though, we’re going to keep it simple and focus only the few parts of the software that we need.
When you start up Blender, it should look roughly like this. You’ll see a version number, along with a cool example of a project that someone did using Blender.
Click outside the central image box to make it go away. Now you’re left with the default Blender scene: a cube, a camera, and a light source (called a lamp).
You can think of it as sort of a virtual photography studio. We’ve got something we want to take a picture of (a cube, in this case), a lamp to provide lighting, and a camera to capture the image. We’re going to make some changes to this setup, but this is the basic idea behind doing Blender relief: we’re going to make a model of our terrain, light it, and photograph it from above. It’s a digital version of the relief techniques of Karl Wenschow, who worked in the early 20th century. Instead of doing shaded relief by hand, as was common then, he built large plaster terrain models and photographed them in a studio to generate his relief images.
We’re going to start by learning how to navigate our 3D scene in Blender. But before we begin zooming and panning around, there’s a little wrinkle: Blender assumes that you own a 3-button mouse, and it uses the middle mouse button for some of these navigation functions. I don’t have one, and I’m guessing you don’t, either (maybe they’re more popular in the 3D modeling crowd?). So, let’s first adjust our settings to tell Blender that we’re just simple people who own simple, 2-button devices.
Head on over to the Edit menu in the upper left of the program, and choose Preferences.
Choose the Input tab (if it’s not chosen already), and check Emulate 3 Button Mouse Notice that if you hover over the checkbox, the tooltip says, “Emulate Middle Mouse with Alt + Left Mouse.” So, now holding the Alt key and clicking the left mouse button will act in place of pressing the middle mouse button that we don’t have. You’ll be making a lot of use of that. Once you’ve got that selection made, you can close the User Preferences window.
So, let’s first practice rotating around the scene. If you hold Alt and click and drag (or middle click and drag, if you are blessed with a 3-button mouse), you’ll rotate around your scene. To pan around the scene, you’ll hold Alt+Shift and then click and drag. To zoom in and out, you’ll hold Alt+Ctrl and then click and drag up and down. You can also zoom in and out with the scroll wheel. This stuff can take some getting used to, so mess around a bit until you get the hang of it.
As said, this is a virtual photographic studio, and if you pan and rotate around you should be able to see that the camera is positioned such that it is set to capture a picture of the corner of the cube. Let’s see what that picture looks like. Go up to the top menu and choose Render, then Render Image. Rendering is the term we use for taking virtual photographs in our virtual studio. It may take a few seconds (depending on your hardware), but you should get a window popping up that looks something like this:
This rendered image should make sense to you, based on where you see the lamp, cube, and camera positioned. Later on we’ll make some changes to all of these things. Meanwhile, you can close the render window and return to where we were before we did the render, which is called the 3D View.
Let’s move on to other areas of the interface. From time to time you’re going to need to select objects in the 3D view (such as that cube, for example). There are two ways to do that: you can either left-click on the object in the 3D view, or on the object’s name in the Outliner, which is the little layers panel on the right side of the screen. Things you select get highlighted in orange by default.
Adjust Some Settings
Now we know our way around the interface, or at least the tiny portion of it that we need to understand. Before we get in too deep, make sure to go up to the top menu and choose File → Save, so that you can keep your progress in the event something goes amiss. You probably will want to keep doing this at regular intervals.
First off, we need to change our rendering engine. I know very little about rendering engines, but basically they are the parts of the program that do all the necessary and complex processing to look at where the camera, lighting, and objects are in a scene, and determine what the final “photograph” should look like. There’s no one right way to do this, and so Blender supports multiple rendering engines, each with its own parameters, advantages, and capabilities. When you open it, Blender starts with an engine called Eevee, and we’re going to switch that to a different engine called Cycles, which this tutorial was built around.
To do that, go over to the bottom panel on the right side of the screen (the Properties panel). There is a set of icons along the left of the panel. Click the second grey icon from the top, which I think is meant to look like a digital camera. Once you click that icon, you’ll see the options in the panel change (this happens with each icon you click — each is much like a browser tab). This will take you to your document’s Render Properties. Change the Render Engine from Eevee to Cycles.
Cycles uses a different method than Eevee to calculate how scenes look. If you go back to Render → Render Image again, you’ll notice that the resulting image takes longer to draw in, being constructed a piece at a time. It may also look slightly different than what you saw with Eevee, though probably not by much. Close the render window.
In any case, you need to switch to Cycles now, or several of the items I talk about later on in this tutorial may not make sense or even show up in the program at all. I do not want to leave the impression that, if you’re planning on using Blender for other stuff, Cycles is better than other rendering engines; each has its own strengths and weaknesses (and a discussion of those would be not only beyond this tutorial, but beyond my abilities). Cycles just happens to be the rendering engine that the technique in this tutorial is designed around.
Now that we’ve switched to Cycles, there’s one more initial setting to tweak. When you selected the Cycles engine in the Render Properties, a couple new options should have appeared right below it. Change Feature Set from Supported to Experimental. I imagine in some future version of the software these settings won’t be experimental, and I’ll try to remember to update the tutorial when this happens. Meanwhile, this setting enables us to actually follow the rest of the tutorial, since the method I use relies on some cool new(ish) Blender features.
We’re working with vectors in Blender, just like we work with vectors in other programs like InkScape, ArcMap, or Adobe Illustrator. To see what I mean, let’s select the cube, by either left clicking directly on it, or on its name in the Outliner. Then hit Tab to go into Edit Mode. Notice that Blender is showing us that this cube is made of eight vertices connected together. These 3D vector objects are called meshes in Blender.
In Edit Mode, we could make some adjustments to these vertices and deform our cube, though we don’t really need to right now. This is just for you to get a better sense of what’s going on behind the scenes. Feel free to click on vertices and move them (with the shortcut G) if you want to play around; it’s fine it the cube ends up deformed. Hit Tab again to go back to Object Mode, or select it from the dropdown menu on the top bar.
We can add meshes in Blender by hitting Shift-A, which brings up a menu of options, including the choice of several meshes. Try adding a few for fun. Notice they show up wherever the 3D cursor is, which is the red-and-white circle with the crosshairs on it. You can move it around by first selecting the Cursor tool on the far left of the screen: now, when you left-click in the scene, the 3D cursor moves. If you want to go back to selecting objects via left clicking, just click on the Selector tool, right above the cursor tool.
We’ll learn more precise ways of positioning meshes later. Try checking out individual objects in Edit Mode to see what they’re made from. To delete any object, just hit Delete when it’s selected. We’re not trying to do anything specific here — the goal is just for you to see and understand what meshes are, so have fun. Once you’re done, we’re ready to move on and get started building our actual relief.
Next Chapter: The Plane