The combination of a
cluster and blend shape is ideal for facial animation because it
lets you tune various subtle deformations. A few common techniques
follow.
In the box below the slider of the Blend
Shape editor, you can enter a numerical value below 0
to invert the deformations, or above 1 to amplify the deformations.
For example, -1 creates a frown, while 1.6 creates a brimming smile:
With or without changing the Blend
Shape slider, you can move, rotate, and scale the cluster
handle to modify the blend shape. The following figure shows some
examples. The face you created will be slightly different because
your original smile is different.
You can use the Paint
Cluster Weights tool again to change cluster weights when
the cluster and blend shape editing deforms certain regions undesirably
or doesn’t give the exact look you desire. You can also use Ctrl
- Z (Windows and Linux) or Control-z (Mac OS X) to undo any undesired changes.