This post is about the buggy surface self-shadowing with the model of the head with the eyes open as a starting point for the animation.
Open eyes of the model are very important at the stage of the modeling and shaping of the character, the eyes in this case are often a key element of expression and personality. But what will happen when the eyes are bound to the bones or are equipped with the morph target of the closed eyes, for example, for blinking. And that’s what will be
As you can see, I drew with the red marker the place where the deformation of the normal form gives black areas over the eyes. There is a small portion of the shadowing from the light source with a big buggy black area from the surface normals. Even when will change the direction of light, in these areas appear dark bug parts. Especially effect is obtained in the game engine UDK.
The way out in this situation will be to take a model with already closed eyes for animation, then there are no bug areas over eyes.