Surfacing - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 195

amount of area, while deemphasizing the rest of the head. Also, it would be good to use as much of the
available UV space as possible, so we're not wasting image space when we eventually create our texture.
There are two ways to fix this. The first requires a little work on your part, and the results are good. The
second is so almost magical that it seems like cheating. It's good to know both, so if the ridiculously easy
method doesn't deliver good-enough results, you can always fall back on the fairly easy way.
The Easy Way: Pinning and Live Unwrap
We'd like the eyes and mouth to have almost the same shape in 2D as in 3D, as they are points of intense
focus on a character. Using the regular selection and editing tools (RMB, Proportional Editing Falloff,
G-key translation), reshape the eyes in the UV Editor to more closely resemble their shape in the 3D
view. On the example head, not a lot needs to be done, but a little tweaking doesn't hurt. With the eyes
and mouth shaped appropriately, use Alt-RMB to select the entire ring of vertices that make up the eye
and mouth holes in the UV Editor. Pin those vertices by pressing the P key.
“Pinning” tells the unwrap algorithm: “I like these just the way they are. Don't mess with them unless I
specifically tell you to.” Anything that is pinned will stay put. However, when you move a pinned vertex
on your own, all of the unpinned vertices in the unwrap adjust themselves to follow. It's a cool enough
thing to see that there is a video in the Web Bucket called live_unwrap.mpeg that demonstrates the effect.
So, with the eyes and mouth pinned, select everything in the UV Editor (yes, it's the A key here as well)
and scale it up until the face takes up the central quarter of the space. Figure 7.29 shows this. Notice that
much of the rest of the unwrap has been scaled to fall outside of the UV space. Let's get it back inside.
Select two vertices at the extreme left and right of the unwrap and pin them ( Figure 7.29 ). Enable Live
Unwrap on the UV menu of the editor's header. With those four pinned vertices selected (two left and
two right) press the S key, followed by the X key to scale them along the horizontal ( x ) axis. The rest of
the unwrap (excluding the pinned eye and mouth vertices) adjusts to follow the motion. What Blender is
doing is actually re-unwrapping the model as you move these pinned vertices, using them as a guide.
If you're following along yourself (or watching the video), you'll notice that the unpinned portions of the
face are distorting pretty badly, causing some bad overlapping into the eye regions. That's bad, so undo
the movement of those outer vertices. To keep things in the face in place better, use Alt-R to select an
entire ring of vertices surrounding the face (careful edge loop construction in the initial model makes this
possible—yeah, edge loops!) and pin them. Now, bringing the four outer vertices inward leaves the face
alone.
And so you proceed with the outer vertices: select one or two, pin them, and move them within the
bounds of the UV space. Do this until the whole unwrap is in bounds. Remembering our goals of mini-
mizing distortion in shape and area of the faces, let's see how we're doing. Press the N key to bring up
the Properties panel in the UV Editor. In the Display section of the panel, enable the Stretch option
and make sure that Area is selected below it. This applies a colorization scheme to the UV display. Faces
that have minimal distortion appear in blue; high distortion, in red. Figure 7.30 shows the unwrapped
mesh before trying to deal with stretch.