Blender for Conworlders (3.2)

If you've read the Planet Construction Kit, you've seen the section on creating 3-D objects. The main programs I talked about were Second Life, which is minimal, and Hammer, which is showing its age. So consider this a supplement: it gives the basics of modeling in Blender.

Blender recently updated its UI, so I've redone this manual, partly so I understand it.

—Mark Rosenfelder, 2018/2022

Preliminaries — Objects — Basic ops — Edit Mode — Extrusion — Precision tools — Texturing — Multiple objects — Bodies — What's next?

Preliminaries

Blender is free, and available here.

You can render scenes right within Blender, but I mostly use it to create objects for Unity (the free game engine) or Second Life. I may do a basic tutorial for Unity sometime, but one nice thing about it is that you can include Blender objects directly, without having to export it to another file type.

One great thing about Blender is that a lot of people use it, so there is a lot of help available online. Google your problem and you can probably get a solution.

The installation should be pretty smooth; if you have problems see the last paragraph. (Note: I'm writing this guide using Blender 3.2.)

Run the program and click on the splash screen. You should see a screen like this:

Congratulations! You've made a cube!

I would suggest you play around with the program, as you could with a 2-D paint program, but there is a special rule that applies to 3-D graphics programs: nothing makes sense, nothing can be found by mere exploration, and nothing is the same between programs. Thus the need for tutorials, such as this page.

(This doesn't mean you can't explore. It's just that random exploration will rarely tell you what you need to know.)

One thing I won't explain— saving projects. The File menu does operate as you'd expect. The native format is the .blend file. To save in other formats, use the Export option.

If you want to start over at any point with the basic cube, select File > New > General.

Objects

Viewport commands

The first thing you probably want to do is get a look at your cube, to see it from different angles. That is, you want to make the viewport camera fly around. You do this by holding down the middle mouse button (MMB) and moving the mouse. Try it. As you can see, you can fly around all you want, but you stay about the same distance from the cube.

To zoom the view, you scroll the mouse wheel up and down. Or for finer control, hold Ctrl, hold MMB, and move the mouse up and down.

It won't make much sense yet, but you can pan the camera by holding Shift, holding MMB, and moving the mouse. This will be a lot more useful when we have more objects. So let's create more!

Deleting objects

First, let's make sure that cube is selected. It starts out that way, but if you explored the program, maybe it's not. The selected object is outlined in orange. If it's not, left-click on it. (It used to be right-click. If you prefer that, change it with Edit > Preferences > Keymap. The very first option is "Select with Mouse Button".)

Now let's get rid of it. Just hit Del, or X. With X (only), Blender will bring up a little confirmation message; click on Delete to delete the thing.

OH NO DON'T DELETE IT! Did you delete it? Just hit undo (Ctrl-Z). Undo is your friend. It's really easy to do something horrible and unexpected, and you can almost always undo it.

If you hit X and change your mind about a deletion, just move your mouse. The confirmation message will disappear, and the object will remain. (All of Blender's confirmation menus work like this. Sometimes this is unexpected— dialogs in other programs don't disappear when you mouse out of them.)

Creating objects

The easiest way to create an object is to let Blender create you a primitive.

Objects are created at the 3-D cursor, which is the little white-and-red circle, not the mouse cursor. Position it using Shift-Right-click, then select a new primitive with Shift-A or the menu selection Add > Mesh.

The Add menu with Mesh selected should look like this:

Do this a few times with different Mesh options; now you have some objects. This is a good time to go back over the viewport commands, to make sure you can navigate around your scene. Try zooming in, then panning. Right-click to select various objects. Try deleting some objects and adding more.

Basic ops

For the basic operations, Blender provides multiple methods; as you get more familiar with the program you will probably gravitate to the keystroke methods, which are the fastest. But let's start with the toolbar in the upper left:
    These determine what happens when you left-click. From the top:
  • Select an object
  • Move the 3-D cursor
  • Select, then move
  • Select, then rotate
  • Select, then scale (resize)
  • Select, then transform (i.e. do any of these)
You can skip the next two, but you might want to play with the last one, which is another way to make cubes.

Pay attention to what mode you're in. E.g., in the picture we're in Move mode.

Moving objects

In Move mode (the third icon on the toolbar), there is a little set of colored axes on the selected object:
In the upper right, you can see another, labeled set of axes. If you didn't fall asleep in geometry class, you shouldn't be surprised that they are labeled x/y/z and that z points upward.

The arrows on the object are actually tools. If you left click on an arrow (and keep holding LMB), you can move the object along that axis by moving the mouse.

The little colored squares next to the axes are also tools; you can drag these to move in two directions at once. E.g. use the blue square to move the object in the XY plane.

Alternatively: press G. (For, uh, go? The program calls it "translation.") The border around the object turns white. Now you can move the object using your mouse. Left-click when it's about where you want. To restrict movement to one axis, use G then the axis name (X Y Z), then move the mouse. E.g. G Z will move the object only up and down.

Another essental tool: duplicate the selected object by pressing Shift D. This immediately puts you into movement mode, so you can move the new object.

Rotation

The next basic operation is rotating an object. Select Rotate mode (fourth icon). As with Move mode, the colored bits can be manipulated. Here I've rotated the cylinder in the Y (green) direction:

Or press R and move the mouse. The select object will rotate— probably chaotically and not in any direction you particularly want. Again, to rotate only in the Y axis, press R Z.

Changing size

The final basic operation is scaling, changing an object's size. Select Scale mode (fifth icon). Once again, click and drag the colored bits to scale the object. Here I've scaled a cylinder along the Y (green) axis:
Alternatively, press S, then move the mouse. This too can be contrained to one axis: e.g. S Z will scale an object only vertically. Or drag the colored squares to scale the object in just two dimensions.

Special views

For most objects, you will very often want orthogonal views: overhead, front, side, etc. These are available on the number keypad.

E.g., here's a little house:

To get an overhead view, press Numpad 7: 5
To get a front view, press Numpad 1:
And to get a side view, press Numpad 3:
These views allow a lot more accuracy. To get back to a 3-D view, just press and hold MMB and move the mouse.

You can also switch between these views by clicking the little colored axes in the top right. E.g. clicking Z gives you the top-down view; clicking the unlabeled blue circle gives you the opposite view, from the bottom.

So far we've been looking at orthographic view. You can also see a perspective view: hit Numpad 5 to toggle back and forth between them. Here's a perspective view of my house:

It looks nicer than the ortho view, and if you use Blender to make final images, this is what you'd want.

But surprisingly, for modeling you should use the orthographic view, because it doesn't distort sizes or make parallel lines into obliques. Once you are (say) making sure two objects properly fit together, you don't want the distortions of the perspective view.

The top left corner of the viewport names the current view— e.g. User Orthographic for user-chosen orthographic, Front Perspective for front perspective.

Edit Mode

Up to now we've been in Object Mode, which affects objects as a whole. For most work you'll actually want to be in Edit Mode, which lets you change individual points.

You change the mode using the menu on the top left. Here's a picture showing the mode control, as well as how our cube looks like in Edit Mode. The whole cube is orange, and individual points are highlighted.

Faces, Edges, and Vertices

Objects in Blender, and in all your favorite video games, are made out of flat polygons. They look solid, but they are just an empty shell— in modeling terms, a mesh. Rounded objects are made up of lots of small flat polygons. You can see this in Blender if you create a cylinder or sphere.

Modeling is modifying this mesh. To do this we need to be able to talk about meshes— specifically, parts of meshes. The important parts are

  • vertices— the individual points that make up lines (and polygons)
  • edges— lines that form the side of a polygon, almost always shared with an adjoining polygon. A polygon can be thought of as a closed circuit of lines
  • faces— individual flat polygons
You work with one of these at a time. Here's a picture of a cube, in vertex, edge, and face mode. Note what is selected, as well as which icon is selected (blue) at the top.

You select an element— a face, edge, or vertex, depending on what mode you're in— with left-click. Try it out, in all three modes. For selecting edges and vertices, there's a bit of leeway; you don't have to click the element exactly.

You can select multiple elements with Shift-LMB. To deselect a single element, click Shift-LMB on it again.

Manipulating stuff

Often, progressing in Blender means learning about entirely new mechanisms you didn't know about before. Not this time! Manipulating elements is just like manipulating objects.

Get yourself a fresh cube; make sure you're in Edit mode, Face mode, and Scale mode. (I've circled the controls for these things in the picture below.) Here I used the green control to shrink the top face in the Y axis.

As before, you can also use S to resize a face, or (say) S X to resize it along the X axis.

And here I took the same face and rotated it in the XY plane, by hitting R Z and moving the mouse. I could also use Rotate mode.

Finally, I selected one point and moved it downward, using the blue (Z) arrow. Then I moved the camera (MMB + move) to see it from a different angle.
As with objects, you can use the mode toolbox and the mouse to move, rotate, and resize. While you're manipulating, it's easy to forget that you're seeing a 2-D view, and what looks right from that angle may actually be terrible. So move the camera around freely to see what it really looks like. (Our brains can only see 2-D views, but are quite good at getting a sense of a 3-D object when it's moving.)

You can do a lot with what you already know, so try it out. Try creating multiple objects and make something, perhaps a toy wagon. (For the wheels, remember Shift-D for duplicate.)

Careful selection

You may have already discovered that it's easy to select things you didn't mean to. Or you want to select all the vertices on one side of an object, thought you did, and discovered that you only selected the top or one side, and the object is now crazily distorted.

First, let's get an X-Ray or wireframe view. There's an icon for this on the right side of the top toolbar (circled in orange below); the tooltip is Toggle X-Ray. Or press Alt Z. Click it a few times to see what it does. When it's active, you can see all vertices; when it's not, you get hidden surface removal. Here's a model of a globe in both views; note how the icon changes.

In X-Ray mode, you can select hidden vertices, edges, or faces. This will take some practice so you can select what you want. Note that to select faces, you now have to click the dot in its middle. The dot is smaller for hidden faces.

Don't forget that you can move the camera to make it easier to select what you want! If you've kept your object aligned with the axes, a top-down, front, or side view (Numpad 7, 1, or 3) will make it easier.

Some quick shortcuts: hit A to select all elements. To deselect them all, click outside the object, or hit Alt A. You can left-click and drag an area to select whatever elements are inside. You can repeat this to get more points.

X-Ray mode is especially nice for geometric objects, like architecture. E.g., here's our cube, in a front view.

I used the mouse to select the vertices on the right. In X-Ray mode, that selects the vertices behind them as well... that is, the entire right-hand face of the cube. Outside X-Ray mode, dragging will select only the visible elements. Moving the camera will make it clear what's selected.

If you have a lot of elements, such as the faces of a cylinder, selecting them all can be tedious. You can select one, then Ctrl-Shift-RMB a face farther away, and Blender will try to select all the ones in between.

Even that may be tedious if you want (say) all the sides of a cylinder, but not the end pieces. So: move the camera such that you're looking at the side of the cylinder, and nothing is behind it. Make sure you're in X-Ray mode. Then hit B and select the centers— roughly the red box in the picture below:

Extrusion

Extruding

You can do a lot with simple objects— but "real" 3-D models are more complex. How are they made? Largely by extrusion. Think of pasta coming out of a pasta maker.

Here I started with the default cube, got into Edit mode and Face mode, selected one side. Then I hit E and moved the mouse. This extrudes out that side, extending the 3-D object. Finally I selected the top face and extruded it upward:

For things like furniture and buildings, it usually works better to extrude in one of the special views, like the front view.

Loop Cut

Another basic tool is subdividing a mesh. In Edit Mode, you'll see more icons along the left. One is Loop Cut. When you select it, then mouse over your mesh, Blender will try to draw a path around it, like this:

Don't click the mouse yet; move around your object and see what other cuts are possible. You'll also see an edit box on the top of the window labelled "Number of Cuts", so you can make multiple cuts at once.

When you're ready, click the mouse, and new edges will be created along the cut. You can move the cut if you keep the mouse held down. (Once again, Undo if things get messy.)

Loop Cut is a mode, so you can keep cutting your object, adding more and more polygons. Don't forget to move back to something like Move mode when you're done.

A windowpane

Let's build a window. Make a cube; make it bigger (S), then flatten it out in the vertical dimension (S Z).

Then use Loop Cut to divide the object in three in both directions. It should look like this:

Make sure you're selecting Faces. Click the center square on the top of the frame, and hit X. Blender will give you a choice of things to delete— click Faces. That face will disappear.

Now you can see the one below it, the one on the bottom of the frame. Do the same to get rid of that center square. Now you've got a frame with a hole in it.

It's not done— the hole has no walls! Finished 3-D models are just hollow shells, but they're not supposed to be open to the world. We need to add those walls. Change the mode to Edges. Click the two edges on the left side of the hold, then press F. This will create a new face joining those two edges.
Do the same for the three other sides. (This is easier if you have X-Ray mode on, since you can click hidden lines.) Now you should have a proper hole with walls. Rotate the object to make sure!
It doesn't look much like a window, since the sides are too big. Let's fix that. Switch to a top view (Num 7), and make sure X-Ray mode is on. Using B, select all the edges on the left side of the hole. Then use the arrow to move them to the left.
Do the same for the other three sides of the hole. (Use A to clear the selection each time.) Now you can rotate your object to see your beautiful windowpane.
There's no window sill. Let's use extrusion to create one.

Select the three bottom faces on the bottom of the window. (On any side, really, but now it will become the bottom.) Hit E extrude just a little (i.e. move the mouse, left click). Do this again for a slightly longer distance.

Now select the three narrow faces we just created. Hit E and extrude them up a bit.
Finally, select the two faces on the right hand side of the sill, and extrude out. Repeat on the left.
There, now we have a window with a nice three-dimensional sill.

(The proportions are a bit off— the sill and the board below it could both be longer. But in 3-D modeling, getting the overall shape right is the most important thing. You can easily change the proportions.)

Try it out!

You probably feel at this point that you don't know much (that's true) and there's a huge amount still to learn (also true). But it's also true that you can do a whole lot with what you know already. It's a matter of learning to apply the tools and methods you've learned, one small step at a time.

For instance: can you figure out how to add crossbars to this window? You won't need any methods beyond the ones I've introduced.

Instead of a window, think of this structure as a simple room. Can you think of a way to add doors and windows to the walls?

Or: Start over with a cube. Use Loop Cut twice on each plane; now you have a cube where each side is divided into nine faces. Turn it into a rock. That is, move the vertices cleverly to make it broader on the bottom, less cubical, and more random.

Can you make a hemisphere? (Hint: you'll be using X to delete something.) Can you make a better rock starting with a sphere or a cylinder?

Or: Try to build that wagon again. But instead of having a big cube for the wagon body, give it a hollow interior. (Think how we created the window sill. Start with a cube subdivided two ways, like we did with the windowframe. What do you extrude to get the wagon body?)

Finally, remember that all the tools work on objects, vertices, faces, and edges. What happens if you extrude an edge? A vertex? What if you select some of those extruded vertices and hit F? This is one way to build— literally draw your vertices out into empty space and connect them to form faces.

Precision tools

Merging parts of the mesh

Another useful trick. Sometimes you'd like to join two parts of the mesh. E.g. let's say I have two cubes missing a face, and I want to join them together. I can move them real close, but there will still be a gap.

Make sure you're in vertex mode, and X-Ray mode. Select two of the vertices you'd like to join; they don't have to be very close together. Hit M and click At Center from the list of options.
Repeat for the other vertices. Now you have a nicely joined mesh.
In the first picture, the two cubes are missing faces. If the faces were not missing, you could still merge the faces... but then you'd have useless internal faces. So, delete them before merging. (Select the face, hit X, click Faces.)

Aligning things

I'm making a staircase, and I've made huge progress: I've created a couple of cubes, resized them to look like steps, and moved them near each other. Only, nothing lines up. Is there a way to fix this besides zooming in really close?
Yes, several ways! The easiest is to align points using Size. Switch to a view that shows you the fronts of your stairs. Mine are aligned along the Y axis, so I want a side view (Numpad 3). Make sure you're in Vertex mode and X-Ray mode. Use B to select the points on the left side of the cubes:
Then hit S Y 0. You should recognize S Y as changing the size in the Y axis; 0 is a shortcut to change the size of the selection to 0. This nicely aligns the points.
Do the same on the right side. Then select the points in the middle of the two stairs and hit S Z 0 to eliminate the vertical (Z) variation.
If you move the camera to get back to your 3-D view, you can see that the stairs now line up nicely:
You can align anything: vertices, faces, edges, objects.

As an exercise, can you figure out how to move some points and align them to make stairs with a diagonal back, like this?

Creating things with precision

Just after you do an action, you have the option to refine it. There's a control in the bottom left corner of the viewport. E.g., after creating a sphere, expand this control to see some options. Segments and Rings determine how many faces the sphere is made with. The defaults are quite generous! Change them to 8 and 6:
You can also change Radius to make it bigger or smaller.

It looks blocky when you're concentrating on it, but if this was an element in a video game— say, a Christmas tree ornament— this is fine. If you look at pipes in video games, you may be surprised to discover that they have just 6 or 8 sides.

You can only change the last action; if you've gone too far, undo a few actions and start over.

The Size (S), Move (G), and Rotate (R) commands also allow more precision. E.g. you can say exactly what angle you want to rotate the selection:

Texturing

So far you only know how to make Blender's default gray objects. How do you give them pretty textures?

It would take another long tutorial to fully explain this, but I'll show you the basics. Let's say you have this simple little house, and this texture. (The original is 1024 x 1024 pixels, since I wanted a fair amount of detail.)

As you can guess, we're going to use the same texture for the entire house— so each face will show just part of the texture. We need to specify how to map the faces onto the textures— this is called creating a UV Map.

Up to this point we've been using the "Layout" mode from the options at the top of the screen. Switch to UV Editing; you should see something like this:

On the left is your UV map; on the right is your 3-D model. It's useful to be able to see both at once. Click Layout and then UV Editing again so you know how to get here and back.

Now we want to grab our image. This is all counter-intuitive, I know, but do all this:

  • There is a red icon on the right side of the 3-D Viewport whose tooltip is Material Properties. Click that.
  • If the tab is empty, hit New.
  • Click the yellow circle after Base Color.
  • Select Texture > Image Texture.
  • Now there's an Open button. Click that and select your texture image.
  • After you select an image, the pane should look like this:

You should see the map applied, probably in some crazy way, to your object. We'll fix it up now.

Select just one face of the roof. Hit U, and select Unwrap. You should see just one (possibly skewed) rectangle in the UV Map, as in the left picture. We want it to look like the right picture.

You edit the UV map exactly as you edit meshes; it's just in 2-D. Try it out: you should be able to select points, use the mouse to select a set of points, move them around with G, and so on.

Note the four icons at the top of the window that determine whether you're selecting vertices, edges, faces, or islands (a set of faces). They're not quite the same as in 3-D Viewport. You can see them a couple pictures back.

In this case, the easiest way is to move each of the four vertices into position, one at a time, with G. Or you could work with edges, using S Y 0 to line them up horizontally, S X 0 to line them up vertically.

When you're done you should see the roof looking good in the 3-D Viewport:

Well, that's it, really. Doing the rest of the house is just tedium: select each face in the 3-D Viewport, move the points into position in the UV Map.

Here's what the little house looks like textured. It would be too simple for a house you can walk up to, but it would be fine for a house in the distance.

Some tips:
  • You can select more than one face and edit them all at once. This can be useful for adjoining faces.
  • You can get a face nicely aligned, then discover it's 90 or 180 degrees off. Go back to the UV editor, select all the points, and rotate (R) the whole face into position.
  • It's better to do the UV maps early in the modeling process, before the object gets too complicated.
  • Blender will create a default UV map for cylinders and spheres. Take a look at it to design textures to match, to save yourself work.
When you're done, go back to Layout (top of screen). Probably you'll find your object is untextured again. To fix this, look for the Viewport Shading icons on the top right. Select the third one, the one that looks like a pie chart. You can see it selected in blue in the picture above.

Multiple objects

I've talked about objects, but so far we've only had one of them. Objects are really collections of meshes; they're a way of organizing your scene. For instance, here's a model I made of a globe of Almea.
You can see your objects at the top of the right-hand pane. Here I have two mesh objects, Globe for the globe itself, and Stand for the stand. The globe is highlighted in orange because it's selected. There's several reasons to separate meshes into different objects:
  • Just to keep yourself organized.
  • It facilitates editing. You can only have Edit Mode on for a single object. That's good, because it means that selecting vertices etc., or moving things, only affects that object.
  • It's often convenient to have separate textures for each object. (The textures for the globe and the stand are quite different.)
  • It can facilitate animation— e.g. if I wanted to make the globe rotate, I'd want to rotate the Sphere object and leave the Stand alone.
  • In a game, you might make entire objects visible or invisible, as a fast way of altering the model.
If you're in Object Mode, an alternative to clicking objects in the viewport to select them is clicking on their names in the right panel.

To make part of an object into a new object: in Edit mode, carefully select the faces you want in the new object. (Make sure to rotate the camera to make sure you have everything you want, and nothing you don't want.) Hit P and click Selection.

You can also join two or more objects into one object. In Object mode, select your object(s), and hit Ctrl J.

To rename an object, make sure it's selected. Click the orange Object Properties icon (visible in the above picture, just above the wrench). You can now change the name in the edit field.

Bodies

To sculpt bodies (to say nothing of animating them) would take another long tutorial. But as a teaser, let me show you some tricks to get started on a figure.

Create a cube and go into edit mode. Make sure you're facing the front of the cube: the red X axis should point to the right, as in the picture below.

Click the blue wrench (tooltip Modifier Properties) on the right side of the window. From the Add Modifier menu, select Mirror. (It's in the second column.) Make sure X Axis is selected, as in the picture.

Move the cube around a little to see what happens. If you move it to the left, you should see a shadowy gray cube appear. The idea is, Blender will mirror everything you do to the original cube. This saves a lot of work: we only have to do half the figure!
Select the top of the cube; extrude it (E) upward, twice. Select the middle cube and extrude it to the left. Select the bottom face of the lowest cube and extrude downward, then move (G) that face leftward. You should have something like this:
We have a very stylized figure. But it's simple enough that you can manipulate all the invididual vertices easily. Move the two halves of the figure together and adjust the proportions. This is most easily done in Front view (Numpad 1), with Vertex and X-Ray modes selected.
One more trick. Select your whole mesh (A). Right-click and you'll get a menu; select Subdivide at the top. Your whole mesh is divided up so there's twice as many polygons.

This is just enough to improve the figure quite a bit! You might see how far you can get. Give it a waist and a butt and a neck. Maybe extrude a foot. Make the limbs and the trunk round, by moving the edges inward. (This is most easily done from the top view, Numpad 7.)

Here's my figure after ten minutes or so of work.

If you get this far, congrats! But I suggest not succumbing to the temptation to Subdivide again and work on the figure much more than this. There are better tools for that, and ways to introduce a sketch so you can get the proportions right. In short, wait for the next tutorial!

What's next?

Probably the Blender documentation.

There are a bunch of tutorials online. Often you can get a question answered by Googling it— e.g. blender how to join two objects.