It’s All In The Eyes
Probably the most important part of creating a realistic 3d character animation is creating and animating realistic eyes. Rigging eyes is easy, but getting them to move right and sync up with realistic and believable facial movements takes a lot of work.
I’ve been experimenting with different ways of doing this in Lightwave. The first and easiest way to “rig” eyes is to simply have two orbs parented to the character’s head bone, and orient them however you want. However, it is hard to ensure that both eyes are looking at precisely the same target at all points in their rotation. It is easy to accidentally create “lazy eyes” with this method. Another method I’ve seen is to use bones for the eyes, and rig them to the eyes in the model using weightmaps. It’s definitely a feasible method, and I plan to try it later today. Once they are rigged, you can target the bones at a target null, which you can then place wherever you want the eyes to be oriented. This gives a realistic rotation of the eyes that always point where you want them to go, allowing a full range of dynamic 3d facial animation.