This paper looks at the effects of shapes and materials on the appeal of human faces. Tests with different material properties that simulate skin are done as well an exploration into the appeal of facial shape.
The studies find that facial shape and proportions play the most significant part when it come to creating a realistic and believable characters. On the other hand texture and materials had the most impact on character appeal and believably.
Some of the limitations of the paper are that when it came to exploring styalizations in textures and shapes are that the styles explored were quite limited, as such these findings may not apply to certain styalized characters. This paper while exploring emotions does not include an animated face as such it could be more difficult to correctly perceive an emotion from the participants point of view.
This paper is useful to me as it directs some focus on the materials on the face. This means that emphasis on skin textures as well as effects like sub-surface scattering and specular maps should be carefully considered when making a face.
Zell, E., Aliaga, C., Jarabo, A., Zibrek, K., Gutierrez, D., McDonnell, R. and Botsch, M. (2015). To stylize or not to stylize?. TOG, 34(6), pp.1-12.