Blendshapes

Facial Animation is probably one of the most important parts in animation, good facial animation will blend right in with your characters performance, and will hopefully give you the ability to emote all of your characters feelings to the intended audience, be it sad, happy and so on.  Using Maya's Blendshapes, we can create all of the different facial poses we would need to believably bring our character to life.

Before we carry on and get into the nitty-gritty or Maya's Blendshapes, I'd like to to introduce this small section, when I work with Maya's Blendshapes, I personally prefer to use a Horizontal Layout, over Vertical Layout, however when I quit Maya and return to it later, the default setup of Vertical is back again, now this is entirely up to you and how you work, but for those that work like me, you can set Maya up so that it is always Horizontal Layout as the default instead : -

Go to your Maya's Other Scripts directory, for example, C:\Program Files\AliasWavefront\Maya4.5\scripts\others, then find the file called createBlendShapePanelMenul.mel, edit it using whatever editor you would normally use, Notepad will do, find the following line : -

string $ma[] = `menuBarLayout -q -menuArray $panelControl`;

straight after on the next line, add this line : -

blendShapeMenuCmd $panel bseMIHoriz;

That's it, when you load Maya up now, Horizontal Layout will be the default layout.

Phonemes and Visemes

A Phoneme is the smallest unit of language that can convey meaning to the audience, for example the "p" in pot, or the "th" in thud.  Alternately, Visemes are the actual visual counterparts of phonemes, one viseme can have many phonemes associated with it, for example the "M" in mat and the "P" in pat are two distinct phonemes, but visually they would look the same, and so could be used under the same viseme (or mouth shape).  Whereas this isn't going to be a modelling tutorial, I will however, showcase the models and various facial shapes I have created along the way.  Let's look into the mouth shapes first, what I should also say though, is if your character has teeth, make sure you don't move the upper teeth when creating blendshapes, they are attached to the characters skull and as such, aren't moveable away from it during speech, only the bottom set of teeth would move during speech because of the jaw joint, if your character has a tongue, be careful to make note of where the tongue is during some mouth shapes, TH, for example would require the tongue to be between the upper and lower teeth.   Also note, Blendshape will not work with groups, so even though we parented the eyes to the head, when creating your head blend shapes, I'd recommend unparenting them, you can parent them back when your done.  Back on track now, for most basic speech animation on a character, the lowest amount of phonemes anybody would use would be 9, these 9 phonemes would usually be broken down as : -

1.  A, I
2.  O
3.  E
4.  U
5.  C, K, G, J, R, S, TH, Y, Z
6.  D, L, N, T
7.  W, Q
8.  M, B, P
9.  F, V

Personally, I prefer to have a bit more control over my mouth shapes, so I use more head shapes to define my phonemes, these are broken down as : -

1.  M, B, P
2.  C, K, G
3.  CH, SH, J
4.  F, V
5.  A
6.  I, U
7.  O
8.  E
9.  N, D, T, L
10.  TH
11.  S, Z
12.  R
13. W, OO, Q 

Visually, these phonemes would look like : -

What I do when creating blendshapes is I create a duplicate of the main head, and then transform it to somewhere I can work on the actual modelling process of generating the required shapes I need, I also name the duplicated version to what they will represent in the BlendShapes List, for example, my first duplicated head would be called, M_B_P, the second head would be called C_K_G and so on. I'd recommend the use of a mirror when creating these shapes.  Obviously, we can't animate all the expressions of the face with just phonemes, we also need to take into consideration emotion and expressions, typically, there is six different base emotions, these are : -

1.  Sorrow
2.  Anger
3.  Joy
4.  Fear
5.  Disgust
6.  Surprise

We can model a good variety of the types of blendshapes that we would need to convey these emotions, at the same time, some could be used for completely different purposes, angry type eyes mixed with a sad looking mouth could convey deep sorrow, typically when creating the types of blendshapes that are used in emotional and also everyday type situations, we create left and right sides by themselves, so we can mix and match how we please, for instance, one eyebrow raised and one angry giving a james bone type feel to a character and so on.  The next set of blendshapes I would create would contain all of my eyelid and eyebrow movements , these would contain the following blendshapes : -

Eyelid Movements

1.  Left Blink
2.  Right Blink
3.  Left Wide Eye
4.  Right Wide Eye
5.  Left Squint
6.  Right Squint

Eyebrow Movements

1.  Left Eyebrow Sorrow
2.  Right Eyebrow Sorrow
3.  Left Eyebrow Anger
4.  Right Eyebrow Anger
5.  Left Eyebrow Raise
6.  Right Eyebrow Raise

Visually, these would look like : -

It wouldn't finish there though, again, the emotional aspect comes into play within the mouth area too, and the phonemes we have originally created just aren't enough to create all the extra emotion we would need from the mouth area, typically, for the mouth area, the extra shapes that would be required would be : -

1.  Pout
2.  Sad
3.  Grimace
4.  Smile
5.  Left Smirk
6.  Right Smirk
7.  Left Sneer
8.  Right Sneer
9.  Open Jaw
10.  Cheeks

Visually, these would look like : -

With these Blendshapes, I believe you have a very good base for which to begin facial animation with, as with most things in life, they are all subject to change within your own projects and requirements, for instance you may create a character whose only purpose is to wander around in the background of the scene, you would only create a few facial expressions where needed, but no phonemes as there would be no lipsync animation taking place.  Once I have all my blendshapes, I select them all 1 by 1 in order of preference, now when I say order of preference, I'm referring to the way I want them to appear in the Blendshape Window, I need them to be in some sort of order, so I wouldn't, say, for example, select the Left_Sneer Blendshape and then select the O Blendshape, as that would be the order they appeared in, instead, I would select them in the order I created them, so the phonemes would be selected first, in order starting from M_B_P, and then C_K_G, and so on.  Once you have them all selected, you then simply go to Deform > Create Blendshape, and the blendshapes are created.  To bring your blendshapes up, just select Window > Animation Editors > Blend Shape, and the blendshape control panel will appear where you have a slider based interface ready to use and animate.  Also, to save on disk space and file size, once I have created the Blendshape list, I will delete all the heads and save to a new file, as the blendshape list now has all the shapes recorded in that, I have all the polygonal heads saved in an earlier saved file which I can load up anytime I need to, to recreate or modify any blendshapes that need it.  So, that it's, we've now covered blendshapes, now all that is left is binding our rig to the actual character polygonal mesh.  We just need to group everything that is is left now, open the Outliner, and select all of the following : -

The select Edit > Group, rename the new group to Character_Rig and then parent it to the Character_World Controller.  That's it.  As usual, you can download the whole rig including all blendshapes here, which I'd recommend doing before we move onto the next stage :-

Final Scene Before Binding With All Blendshapes - Maya 4.5 Only - Zip File (469kb)

The Binding Phase : -

Character Rigging Tutorial - Eighth Page