It looks like I never posted this.
Pretty short but interesting behind the scene video. I am mostly posting it as it features Maui’s facial rig and GUI picker.
On a side note, I have the feeling the animator is navigating through the brow picker using the left right keys of his keyboard.
I have just found a very old Pixar presentation where Pete Docter demonstrates an antique version of Pixar’s animation software Menv (Presto) running on Silicon Graphics.
The principle has changed much but the software allows much more finessing nowadays.
Have a look and compare to the latest iteration of the sofware featured in Part I and Part II below.