Documentation:Corrective shape keys
These are instructions for how to set up shape keys on a rigged makehuman model in blender.
Step by step to make it work.
On the character body armature modifier, activate the function "Display modifier in Edit Mode"
Create a basis shape key and then a deformation shape key, give it a suitable name. Pin the shape key to always show.
Select the bone you want shall control the shape key and pose it to the position where you want full shape key deformation. Remember the bone name and wich axis you rotate it, in this example bone "lowerarm01.L" local X rotation - press key R then XX.
Select the body and edit the mesh until desired shape for that pose. Proportional edit is very useful.
Reset the bone to default position - press key ALT and R
Prepare the shape key to be driven by the bone.
The Value field color is now purple. Unpin the shape key and you will see the mesh transforms back to the default shape.
Open "Graph Editor" - "Edit Drivers"
Select the shape key to the left and the tab "Drivers", in the field "Object" select the skeleton and "Bone" in this example "lowerarm01.L" As this example want the bone local X rotation to control this shape key select "X Rotation" and "Local Space".
Finish by setting "Type:" to "Averaged Value".
If the shape key shall deform on the negative rotation axis, add the driver modifier "Generator" and value -1.000 as shown here.
Rotate the bone on local X axis (key R then XX) and the shape will deform the mesh.
Adjust the shape key until satisfied. The shape will always deform in a strait line.