Shape key need driver for facilitate the animator. It will be helpfull like shape rig help replace rig visualization. You just need to move the driver for animate the parameter of shape key. A few day's ago my friend asking me how to create driver for shape key. I've written tutorial about blender shape key driver with Bahasa and now, i want to write it into english.

I am using simple object for this shape key driver tutorial, i just use cube on this tutorial. The cube will be transform to pyramid. There is tutorial step by step how to add driver shape key on blender 2.6. I am using Blender 2.63 for this tutorial. Let start the tutorial

You need to adding one cube and add two shape key into the cube. For example, i adding two shape key. They are Basis and Triangle. Basis for default cube and Triangle for pyramid shape.

Add two shape key into cube

Go to edit mode > Apply shape key in edit mode > set the value : 1.000 > Select vertices on top of he cube > Scale on center. So your cube will be look like pyramid :D. Let try to decrease and increase the value, you will see the cube trasnform. When you set the value approaching 1.000, the cube will be look like pyramid, and when you set the value approaching 0.000, the object will be look like the cube.

Set the value and shape

value sample

It's just simple sample of shape key animation. You must insert keyframe on the value bar, can you think when you adding shape key into character. You need to move the rig on 3D view and increase / decrease the value of shape key, and insert every keyframe on different window (3D View and Properties)? It will be complicated. But with the shape key driver will be helpful for animator, because just need insert and modify the animate in 3D view window.

Let adding the driver using Right Click on value > Add driver. If the adding succes, color of value will be change to purple, and you can't edit the value with drag like before. You need the controler to set the value.

Add > Armature > Single Bone, it's for the driver controller.

Add driver controller

Go to animation window, it will be help you to configure the controller. On graph editor, select driver on type and select the value. Show the properties with press N when the mouse on graph editor, your window will be like image bellow.

Change the type of driver to averaged value. Ob / Bone > the name of armature and bone for driver. In example, the name of Armature is Armature, and the Bone is bone. I am using local variable space, just trying and you will be know the mean.

For trying the driver, you must select the bone and go to pose mode. Let's try to move the controller on X, Y or Z axis. Is the cube transform to pyramid? Happy Blending