Assigning drivers to the shape keys
In the previous recipe, we created three different types of shape keys. Besides the fixing shape keys, that have a fixed value (no pun intended), we now need a way to set the amount of influence of the other two types of shape keys, facial expressions, and the muscle movements during the animation. This is accomplished by setting drivers, though with different kinds of controls.
Getting ready
Start from the previously saved Gidiosaurus_shapekeys.blend
file:
Go to the Outliner and hide the Armor object.
Select the Armature rig, switch to the Octahedral bones draw mode, and press Tab to enter Edit Mode; zoom to the character head and add six bones located as follows: two bones close to both the right and the left eyebrows, two bones close to both the sides of the grin snout area, and two bones close to the nostrils. Enable the Names item in the Skeleton subpanel under the Object Data window and rename the bones accordingly and with the correct .L or .R suffix...