Emotional authenticity of facial expression effects in 3D Animation‎

The role of realistic wrinkles and folds ‎

• One of the ways to enhance emotional authenticity in 3D animation facial expressions is ‎adding realistic wrinkles and folds effects of in the facial skin. ‎ Wrinkles and folds are also known as “smile lines”, “Crows Foot” and “Thinking ‎wrinkles”. They all take part is various expressions like smiles, frown, browse raisings etc’. ‎Creating realistic wrinkles and folds effects is a real “secret weapon” in 3D animation. It ‎literally upgrades the overall facial expression quality; What might seem as a nuance, is of ‎great importance, and of great value for all animation types and styles and for all sorts of ‎character design. ‎
• Though it may sound counter gut feeling, realistic wrinkles and folds are most valuable ‎even with simplistic or abstract characters’ designs. Let’s assume we are working on a ‎very simplistic cartoony / abstract character; for example a ghost or a monster with no ‎nose or teeth. Even with such a figure, as long as the facial features carry enough details ‎to allow the viewers to associate it with humanoid or animal face, wrinkles will deepen ‎the emotional effect. Done appropriately and in right timing, it will make the movie much ‎more enjoyable. It would evoke in the audience “near-consciously” recognition of familiar ‎facial expressions that they would associate with the right emotions. ‎
• Human ability to recognize facial nuance is a primal intuition all seeing humans share. ‎Most of them gather huge experience with encoding facial expressions from almost day ‎one. This human skill gives animators and sketchers the ability to reach high quality and ‎credible facial expressions even with very abstract characters.
• It is easy to demonstrate how wrinkles are an integral part of compelling facial ‎expressions. If we take a look at the following photo series
  
  
  we see a comparison between attempts to create a smile without the fashionable, deep ‎lines of the mouth, and between smiles with such lines on the sides. We promptly notice ‎that without said lines we sense that something essential is missing. It is true for every ‎type of mouth in any character. Even a wide smile without these lines, will make us feel ‎that it lacks something. It would feel less real, less emotional and uncanny. ‎ Add this simple detail - "And see the wonder"; The smile suddenly seems perfect, human ‎and cordial.‎
• In terms of 3D animation technique, we usually do not use bump maps or material shaders ‎to create smile lines elements. It is way more common to create them in modeling; the ‎lines are sculpted in the blendshape target meshes at the point where the mouth is ‎stretched wide. Thus, smile lines are not included in the texturemap / hypershade method ‎shown further below. The above smile lines are brought here as an example of their ‎prominence. Their reference here helps me right away to make my point and stress that ‎the effect of folds and wrinkles is significant.‎
• Creating wrinkles and integrating them with the entire of the animation, is a complex ‎technical process. It requires advanced knowledge of a distinct part of the Maya software ‎called Hypershade (of course, equivalent procedures exist in other 3D animation ‎software). The Hypershade environment is an editing window whereby the 3D material, ‎shaders & textures are being created and edited. ‎
• For adding animated wrinkles (i.e., controlling their occurrence and disappearance timing ‎according to the appropriate expressions) we must build an appropriate infrastructure. In ‎the Hypershade environment, we need to create an objects’ network as seen here:
  
  
  This special rig of objects: utility nodes connected to bump and image nodes, ties the ‎keyed values of the wanted target shapes (the ones than need wrinkles) from the ‎blendshape attribute between 0 to 1, together with the 0 to 1 material opacity bump map attribute (a grayscale 2D texture map depicting a wrinkle in UV layout). ‎Thus make the bump opacity value dependant on the target blendshape value. This, after ‎rendering, will result in the desired effect of impressive animated wrinkles. They will appear and ‎disappear in the correct spots and in perfect timing throughout the animation. This will take place along ‎with the gradually embossing co-responding expressions of the wrinkles, while tapering in and out to the character's ‎textured facial skin ‏.‏‎ Nifty!‎‏
  
  
  
• A character demo showing off all its shapes with wrinkles in animation:‎‏
  
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