Building the body

Relevant to Blender v2.31

Change to the front view with NUM1 and add a cube by pressing SPACE and selecting menu Add, submenu Mesh, sub-submenu Cube. (In the book we will use SPACE>>ADD>>Mesh>>Cube as shorthand for these kinds of actions). A cube will appear (Figure 4). This newly added cube is in EditMode, a mode in which you can move the single vertices that comprise the mesh. By default, all vertices are selected (highlighted in yellow - unselected vertices are pink).

We will call our Gingerbread man "Gus". Our first task is to build Gus's body by working on our cube in EditMode. To see the Blender tools that we'll use for this purpose, press the button showing a square with yellow vertices in the Button window header (Figure 5), or press F9.

Now locate the Subdivide button in the Mesh Tools panel and press it once (Figure 6). This will split each side of the cube in two, creating new vertices and faces (Figure 7).

With your cursor hovering in the 3D window press AKEY to deselect all elements. Vertices will turn pink. Now press BKEY; the cursor will change to a couple of orthogonal grey lines. Move the cursor above the top left corner of the cube, press and hold LMB, then drag the mouse down and to the right so that the grey box encompasses all the leftmost vertices. Now release the LMB. This sequence, which lets you select a group of vertices in a box, is summarized in Figure 8.

	Box Select
	On many occasions you may have vertices hidden behind other vertices, as is the case here. Our subdivided cube has 26 vertices, yet you can only see nine because the others are hidden. A normal RMB click selects only one of these stacked vertices, whereas a box select selects all. Thus, in this case, even if you see only three vertices turning yellow you have actually selected nine vertices.

Now press XKEY and, from the menu that pops up, select Vertices to erase the selected vertices (Figure 9).

Undo

Introduced in version 2.3, Blender has a Mesh Undo feature. Pressing UKEY in EditMode makes Blender Undo the last Mesh edit. Keep pressing UKEY to roll back changes as long as the Undo buffer will allow, while SHIFT-U re-does changes. ALT-U opens a menu with a list of possible undoes, so that you can easily find the point to which you want to revert to. Mesh Undo works only in EditMode and only for one mesh at a time. Undo data is not lost when you switch out of EditMode, only when you start editing a different mesh. Another way to revert to the previously saved state is to press ESC in the middle of an action. This cancels the action, reverting to the previous state.

Now, using the sequence you just learned, Box Select the two top-rightmost vertices (Figure 10, left). Press EKEY and click on the Extrude menu entry to extrude them. This will create new vertices and faces which you can move and which will follow the mouse. Move them to the right.

To constrain the movement horizontally or vertically, click MMB while moving. You can switch back to unconstrained movement by clicking MMB again. Alternatively you can use XKEY to constrain movement to x axis, YKEY for y axis and so on.

Let's create Gus's arms and legs. Move these new vertices one and a half squares to the right, then click LMB to fix their position.

Extrude again with EKEY then move the new vertices another half square to the right. Figure 10 show this sequence.

Gus should now have a left arm (he's facing us). We will build the left leg the same way by extruding the lower vertices. Try to produce something like that shown in Figure 11.

We use the Extrude tool three times to produce the leg. We don't care about elbows, but we will need a knee later on!

Coincident vertices

If you extrude, and in the process of moving you change your mind and press ESC to recover, the extruded vertices will still be there, in their original location! While you can move, scale, or rotate them by pressing GKEY, you probably don't want to extrude them again. To fully undo the extrusion, look for the Remove Doubles button, highlighted in Figure 12. This will eliminate coincident vertices. Figure 12. The Edit Buttons window.

The CD contains a .blend file with this example, saved at various modelling phases. The first file, Quickstart00.blend contains what you should have obtained up to now. Subsequent steps are numbered progressively, Quickstart01.blend, Quickstart02.blend and so on, while Quickstart.blend contains the final result. This standard applies to all other examples in the Book.

Now we'll create the other half of Gus:

1. Select all vertices (AKEY) and choose the 3D Cursor entry in the Rotation/Scaling Pivot Menu of the 3D Window header. (Figure 13).

2. Press SHIFT-D to duplicate all selected vertices, edges, and faces. The new objects are in Grab mode, press ESC to exit from this mode without moving the vertices.

3. Press MKEY to open the Mirror Axis Menu. Choose Global X. The result is shown in Figure 14.

4. Deselect all then reselect all by pressing AKEY twice, then eliminate the coincident vertices by pressing the Remove doubles button (Figure 12). A box will appear, notifying you that eight vertices have been removed.

	Reference center
	In Blender, scaling, rotating and other mesh modifications occur either with respect to the cursor position, the object's center, or the barycenter (center of mass) of the selected items, depending upon which entry of the Rotation/Scaling Pivot Menu (Figure 13) is active. The crosshair button selects the cursor as reference.

	Moving the cursor
	To place the cursor at a specific grid point, position it next to where you want it and press SHIFT-S to bring up the Snap Menu. The entry Curs->Grid places the cursor exactly on a grid point. The Curs->Sel places it exactly on the selected object. The other entries move objects other than the cursor.

Gus Needs a head:

1. Move the cursor so that it is exactly one grid square above Gus' body (Figure 15, left). Add a new cube here (SPACE>>ADD>>Mesh>>Cube).

2. Press GKEY to switch to Grab Mode and move the newly created vertices down, constraining the movement with MMB, for about one third of a grid unit (Figure 15, right).

3. This produces a rough figure at best. To make it smoother, locate the SubSurf Toggle Button (Figure 16) in the Mesh panel and switch it on. Be sure to set both the two NumButtons below to 2.

SubSurfacing is an advanced modelling tool, it dynamically refines a given coarse mesh creating a much denser mesh and locating the vertices of the finer mesh so that they smoothly follow the original coarse mesh. The shape of the Object is still controlled by the location of the coarse mesh vertices, but the rendered shape is the smooth, fine mesh one.

4. Switch out of EditMode (TAB) and switch from the current default Wireframe mode to Solid mode with ZKEY to have a look at Gus. He should look like Figure 17 left.

5. To make Gus look smooth, press the SetSmooth button in Figure 16. Gus will now appear smooth but with funny black lines in his middle (Figure 17, middle). These lines appear because the SubSurfed finer mesh is computed using information about the coarse mesh normal directions, which may not be self consistent, that is, some face normals might point outward, some inward, if extrusions and flippings have been made. To reset the normals, switch back to EditMode (TAB), select all vertices (AKEY), and press CTRL-N. Click with LMB on the Recalc normals outside box which appears. Now Gus should be nice and smooth, as shown in Figure 17, right.

Press MMB and drag the mouse around to view Gus from all angles. Oops, he is too thick! To fix that, switch to side view NUM3. Now, switch to EditMode (if you are not there already), then back to Wireframe mode (ZKEY), and select all vertices with AKEY (Figure 18, left).

Let's make Gus thinner:

1. Press SKEY and start to move the mouse horizontally. (Click MMB to constrain scaling to just one axis or press YKEY to obtain the same result). If you now move the mouse toward Gus he should become thinner but remain the same height.

2. The three numbers on the 3DWindow toolbar show the scaling factor. Once you constrained scaling, only one of these numbers will vary. Press and hold CTRL. The scale factor will now vary in discrete steps of value 0.1. Scale Gus down so that the factor is 0.2, then set this dimension by clicking LMB.

3. Return to Front view and to Solid mode (ZKEY), then rotate your view via MMB. Gus is much better now!