The Related Settings in Muscle, Expression and Modify Tabs

In the Face Key panel, there are three tabs, Muscle, Expression and Modify. Although they appear in separate tabs, they are actually related effect-wise.

• Muscle and Modify:
  If you set the Expression Set to Default mode in the Muscle tab, the muscles you are adjusting are actually corresponding to the blendshapes in the Modify tab.
  
  For example, select the eyebrow areas and drag up, you are actually increasing the Brow_Raise_Inner_L or Brow_Raise_Inner_R values.
  
• Expression and Modify:
  The presets in the legacy Expression Style are composed of different blend shape values in the Eyebrows, Eyes, Nose and Mouth pages in the Modify tab.
  
  For example, the AU_2 in the 09-FACS is the combination of different slider values (Brow_Raise_Outer_L and Brow_Raise_Outer_R).