Create set driven keys with the "_SDK" node of the controllers as your driven object and the custom attributes of Jaw_Control as your driver. That's why it's called an "SDK" node, remember?

Fig 15. Setting Up the Set Driven Keys

 

A blendshape or an influence object can be added at this point to help refine the pose if some of the vertices don’t look quite right. (Hey, I just thought of a new tutorial…).You may remember that earlier we also left the Y axis rotation on the lip bones unconstrained. I like to make a top and bottom "Lip Roll" attribute and driven key this rotation to get the lips to curl in and out for puckering and kissy faces and the like. Another neat trick is a "Lip Follow" slider that drives the parent constraint weights of all the group nodes.

Add an attribute to Jaw_Control named Lip_Follow that ranges from -1 to 1.

Select all of the parent Constraint nodes under the “_group” nodes for all of your Lip controllers. Open the Set Driven Key dialogue and load these objects as the Driven. Load Jaw_Control as the driver.

Fig 16. Set Driven Key Option Box

Create a driven key between the Mouth_Top_W0 attribute and the Lip_Follow attribute at their default values.

Now change the value of Mouth_Top_W0 to 0, the Lip Follow attribute to -1, and set a driven key.

Change the parent constraint weights to 1 and the Lip Follow to 1 and key again.