Shapes and Morphing - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 287

● Cheeks are pulled up, bulging out.
● Large crease between mouth area and cheeks becomes sharper.
● Wrinkles under the eyes become more pronounced as the cheeks bunch up into them.
● Laugh lines at the outside edges of the eyes show.
● Eyelids may pull back slightly.
● Nostrils may flare.
As you craft your mesh to show a smile then, you will have to make all of these changes. It might seem
like a lot to observe and do, but if you just make the mouth curl and change nothing else, your character
will look like a robot. Keeping all of these things in mind, work on your shape. Every now and then,
run the Value slider up and down repeatedly and watch the transition in the 3D view.
Another thing to think about when creating shapes for faces is the underlying bone and muscle structure.
You can't just randomly start pushing vertices around and think that the result is going to look natural.
For example, when pushing the cheeks upward, remember that in real life there would be muscle and
bone beneath that skin and the cheeks would slide along it, not just move straight up. As you play with
the Value slider, watching the face change in real time, see if it gives you the feeling that the skin is
moving over an underlying structure and that that structure remains intact. If you get that sense, then you're
doing it right. If not … keep working.
You've already seen one of the two methods for altering the shape of a shape key: Edit mode. When
working in Edit mode to create effective shapes, PEF is your best friend. Remember to frequently check
the state of your work by adjusting the Value slider in Object mode.
A more intuitive way of creating shapes is through the sculpt tools, in particular the Grab brush. In Chapter
8 on sculpting, much is made of the Multiresolution modifier and using the sculpt tools for adding fine
detail to existing models. However, you will find that switching to Sculpt mode and using the Grab brush
provides a great workflow with shape keys.
The only restriction when sculpting into shapes is that the target shape key must be selected and pinned
in the Shape Key panel. If you want to see this in action, the Web Bucket video sculpting_shape_keys.mpeg
provides a good example.
Preparing Shapes for Animations
The Value slider for each shape key is animatable just like any other property. You set a frame, set the
value, and either press the I key while hovering the mouse over the control or RMB clicking on it and
choosing Insert Keyframe . When trying to key complex facial animation though, the process of selecting
a shape key, setting a keyframe, selecting a different shape, etc., is tedious and unintuitive. Therefore, most
users use Blender's animation Drivers system to link sets of shape keys together under Custom Properties
or to bone controllers.
For full instructions on using Custom Properties, you can refer back to Chapter 8, in the section on build-
ing a switch for the arm's IK/FK controls. The short version is: Add a custom property to the armature