As I am sure we all know, facial movement is really important to get good emotion in an animated character. But how do we do this? I will be looking into a few different facial rigs and seeing which is better for what purpose according to people who use them. Then trying to make a decision on which to use for my current character myself.
Firstly, there is the Image metric facial rig. What this does is captures the face of an actor down to the pore, and uses it to make realistic changes to the face and its expressions. They capture the images using a set of cameras in a well lit space, which are then turned into 3D data using a program that I am trying to find the name for but am not able to yet. It has to be out there as this was being done in 2008 and has been around for a little while now. This seems like it would be great for more realistic animations and doing VFX.
Another way to do facial modification is using morph targets, which is what I have done mostly myself, this requires the setting up of controllers for the different targets, such as can be seen in the Norman rig or many other rigs with controllers. It allows the creator to have control over the extreme poses of each facial movement. including lips, eyes such as blinking, and so on.
NURB Curves have been used in many productions, but the one I found the best posts about it where from the animated movie Delgo. I was not a big fan of the movie itself, but the animation in it was pretty enough. the Animation director that worked on it said “…NURBS curves as influence objects on a poly mesh that is bound to control joints using smooth skining. We retained the ability to create blendshapes if necessary, but we gained, among other things, the ability for animators to create very subtle or extreme changes in expressiveness without having to send the character to a modeler for new target shapes. In most cases, this process is simple and fast enough that you can rig a head in a single day.”
There are also many programs out there that will do this work for people and make it much easier, though I am not a fan of lack of control, I do like the speed they bring and sometimes that is what is needed. One such program is called Face Robot. Which uses points input by the user to define things like eye or mouth deform points and creates the animations from there.
References:
http://www.creativecrash.com/maya/tutorials/character/c/facial-animation-rig-for-delgo
Ancel's Designs 