Shapes and Morphing - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 281

Chapter 10
Shapes and Morphing
Before we begin animating the character using the rig in Chapter 9, there is one more bit of work that
needs to be done. The armature and bone system is perfect for making deformations that in real life would
be driven by a skeleton or other kind of rigid structure. While the human face is partially driven by this
method (the jaw), for the most part its great expressiveness is created by muscles that are attached to the
skull, pulling and bunching the skin of the face. You could set up a bone structure to try to do this (it's
been done!), but there is a more intuitive method for achieving this kind of animation.
Our goal as animators is to achieve specific shapes and configurations of the face (expressions, like a smile),
and the easiest way to do this is to simply edit our model to have the correct look. Blender's system for
saving different shapes within the same model is called Shape Keys . Other 3D packages call this morph
targets , blend shapes , or some combination of those terms.
In our example file, we will use Shape Keys exclusively to create facial expressions, but the system is by
no means limited to that functionality. The ability to have your meshes change their shape over the course
of an animation in such a detailed and finely controllable way can be useful for fixing stubborn deforma-
tion issues with armatures, changing one object into another, and enhancing character animation. The point
is to keep Shape Keys in mind when you are approaching animation problems. It might hold the
solution.
Creating a Shape Key
Figure 10.1 shows the example character (in pretty GLSL textured viewport mode) and the Mesh proper-
ties. The Vertex Groups panel contains all of the groups automatically created during the rigging and
skinning process. The UV Texture panel contains the three UV projections we used to projection paint
the face's textures. Between those is the Shape Keys panel. Note that there are a number of shape keys
already created. Figure 10.2 shows several of these keys selected, and their various effects on the mesh.