Blender for Conworlders
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.
—Mark Rosenfelder, 2018
Basic ops —
Edit Mode —
Precision tools —
Multiple objects —
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 basics 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 2.79b.)
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.
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!
Creating and 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, right-click on it. (You'd think it would be left click. You'd be wrong.)
Now let's get rid of it. Just hit Del, or X. 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 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.)
The easiest way to create an object is to let Blender create you a primitive. First make sure the Create tools are visible. Check the upper left; there should be a series of tabs: Tools, Create, Relations, etc. Click Create. The toolbar changes; it should look like this:
Now you have some tools. To create something, left-click on the screen about where you want it, then click on one of the tools. For now stick to Cube, UV Sphere, Ico Sphere, Cylinder, Cone, Torus. (Create a Monkey if you want.)
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.
There are two ways to move objects. First, note that there is a little set of colored axes on the selected object:
In the lower left, you can see another set of axes, labeled. 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.
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.
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.
Changing an object's size is called scaling it. Press S, then move the mouse. Try it out. You can soon make a mess of your scene, so don't forget about Undo.
The final basic operation is rotating an object. Select a cube (or better yet a monkey) for this.
Hit R and move the mouse. The select object will rotate— probably chaotically and not in any direction you particularly want it to. We'd better learn about constraining axes.
All three of these operations (G translation, S scaling, R rotation) can be contrained to operate on just one axis.
Just press the operation key, then the axis name (X Y Z). Then move the mouse.
For instance, here's the opening cube after scaling it on the Z axis. (Press S Z then move the mouse.)
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:
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.
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 Ortho for user-chosen orthographic, Front Persp for front perspective.
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 bottom 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
You work with one of these at a time, using the little menu at the bottom of the screen.
- faces— individual flat 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
- vertices— the individual points that make up lines (and polygons)
Here's a picture of a cube, in face, edge, and vertex mode, with what the little menu looks like.
You select an element— a face, edge, or vertex, depending on what mode you're in— with right-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-RMB. To deselect a single element, click Shift-RMB on it again.
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.
Make sure you're in Face mode, and right-click the top face of a cube. Hit S and slightly move the mouse: the entire face enlarges or shrinks:
And here I took the same face and rotated it in the XY plane, by hitting R Z and moving the mouse.
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.
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.)
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 a wireframe view. Just to the right of the vertex-edge-face buttons on the bottom of the screen, there's a button that toggles visibility of all vertices. 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 the wagon in both views, with the appearance of the buttons in the inset.
In wireframe 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. Hit it again to select none. Hit B to drag an area and select whatever elements are inside. You can repeat this to get more points.
Wireframes are especially nice for geometric objects, like architecture. E.g., here's our cube, in a front view.
I used B to select the vertices on the right. In wireframe mode, that selects the vertices behind them as well... that is, the entire right-hand face of the cube. Outside wireframe mode, B 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-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 wireframe mode. Then hit B and select the centers— roughly the red box in the picture below:
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.
Now I selected the top diagonal 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.
Another basic tool is subdividing a mesh. If you hit the Tools tab on the lefthand panel, you'll see lots of mesh-changing tools. You could play with Subdivide, which divides the current object on every dimension. This will give you plenty of polygons to work with, but often too many in places you don't need them. I prefer to make the cuts myself with Loop Cut and Slide.
Here's a picture showing the part of the toolbar with this command highlighted, and its effect. Get yourself a cube and change to Edit Mode. Click Loop Cut, then move the cursor to the middle of any edge. You should see a purple line extending around the object:
Move to one of the other edges: you can divide the object along any plane. Left-click to accept this division; or use the mouse wheel to add more divisions, pressing left-click when you have enough. In either case your new edges will be selected, and you can move them if you want. Left-click once again to stop that.
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 wireframe 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 wireframe 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.
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, showing wireframes. Select two of the vertices you'd like to join; they don't have to be very close together. Hit Alt 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.)
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 showing wireframes. 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. Look in the lower part of the left-hand toolbar. E.g., right after creating a sphere:
You can change Size to make it bigger or smaller.
The Segments and Rings determine how many faces the sphere is made with. The defaults are quite generous! Change them to 8 and 6:
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.
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:
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.
Start by selecting one of the faces that make up the roof. Hit U, and select Unwrap from the options that appear.
There's a little view selector button in the bottom left. It's showing a cube, which represents 3D View. Select UV/Image Editor instead. You should see something like this:
(Note the view selector in the bottom left.)
We're now editing the UV map, but most of the tools are the same as for editing meshes. Try it out: you should be able to select points, use B to select a set of points, move them around with G, and so on.
Look closer at the tools farther along...
First, notice the controls on the right: these determine whether you're selecting vertices, edges, faces, or islands (a set of faces). For some reason the icons are different here. The vertices one is blue because it's on— we are selecting vertices.
Next, notice the Open button. Click it and load your texture. Now you should have something like this:
If you recall, we selected a side of the roof. So, move the points so they enclose the roof portion of the texture:
Use the view selector to go back to 3D View. At first it looks like nothing has changed. There's a button called Viewport Shading to the right of the mode selector; I've drawn an arrow pointing to it in the picture below. Select Texture and you should see your textured roof.
Well. Very likely you'll just see black shapes, because the lamp is in the wrong location. The lamp? Well, you have to light things in 3-d modeling! Blender gives you a default lamp, which is never where you want it, but you can move it.
If you're in Object Mode, you can just click the lamp and move it using the arrows, just as you'd move a mesh. Here's a picture showing the lamp (selected, so it's orange). I've moved it to shine onto the house.
Well, that's it, really. Doing the rest of the house is just tedium: select each side, go to the UV Map, move the points into position.
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.
So far I really only talked about objects when we just 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, Sphere for the globe itself, and Stand for the stand (highlighted in orange because it's selected). There's several reasons to separate meshes into different objects:
- If you get into the UV editor and your texture isn't there, click the picture icon next to the New|Open control. You'll see a list of the textures you've opened; just select your image there.
- You can select more than one face and edit them all at once. This can be useful for adjoining faces.
- The alignment options (last section) come in very useful in UV editing.
- 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 the whole face into position.
If you're in Object Mode, an alternative to right-clicking objects in the viewport to select them is left-clicking on their names in the right panel.
- 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.
- 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.
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, right-click it in the list in the right-hand pane, and select Rename.
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.
Look in the right-hand pane and click on the little wrench. 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 vertices and wireframes selected.
One more trick. In the left hand pane, Tools tab, there's an option Subdivide, located just above Loop Cut. Select the entire mesh (A) and then Subdivide, just once. 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 proportoins right. In short, wait for the next tutorial!
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.