leveraging facial muscle variation

zygomaticus major dimple

Anatomical variation is a surprisingly ignored consideration for face tracking/facial mocap in tech and entertainment. Simplified anatomy diagrams are often accepted as universally applicable to all faces and few further questions are asked. The reality is: FACIAL MUSCLES ARE HIGHLY VARIABLE.

frontalis variation

frontalis shapes illustration

The frontalis muscle (forehead muscle that elevates your eyebrows) does not always follow the prototypes presented in anatomy diagrams. Frontalis shapes are widely variable, and this variability is a major contributor to age and expression-based wrinkle formations and brow shapes.

inner brow raiser: deep dive

inner brow raiser wrong

Inner brow raiser is one of the most difficult facial actions to find clean references for. Many sources fail to find actors who can separate their inner brow raiser from other facial actions such as outer brow raiser (from frontalis, pars lateralis) and brow lowerer (from corrugator).

 ARKit to FACS Translation

Apple's Typo - "Outter"

If you or your team are using open-source face tracking kits to: animate faces overlay virtual content create expression-based events . . . figuring out what's what can be confusing; so I have created a ARKit translation guideline - starting with brow movements.

a wrinkle in time, part II: static forms

This post is Part II of a series on wrinkles types. Part I focused on wrinkle caused by repeated facial expressions – dynamic wrinkles. Part II will focus on another class of wrinkles: static wrinkles. While static wrinkles may not as exciting as dynamic expressions wrinkles, they are just as important to consider when applying to your character. As stressed in Part I, every line tells a story.

a wrinkle in time, part I: building characters with real story lines

Wrinkles are more than just a product of aging; they are maps that guide us through an individual’s emotional history, genetic tendencies, and lifestyle habits.

welcome. I’m looking for work!

Hello and welcome to Face the FACS. This blog is a passion project where I pour my interests and cross-disciplinary research into one place to share with the world. I’ve been studying the art and science of facial expressions for almost eight years. I started out by using the Facial Action Coding System in an… Continue reading welcome. I’m looking for work!

breaking down nose wrinkler (AU9)

An exploration of the nose wrinkler action and the evolution of changes caused by layered expressions.

the secret life of inner brow raiser

AU 1 & friends

While people can generally activate inner brow raiser spontaneously, inner brow raiser stakes claim as one of the most notoriously difficult action units to trigger during posed expressions. Its elusive nature plagues various fields – from academic research to machine learning and character art. 

cheek raiser vs. lid tightener

Whether you’re using an expression model to pose AUs for academic research, product-based machine learning, or character art, you will face challenges acquiring pure examples of cheek raiser and lid tightener.

comparative anatomy (sneak preview)

chimpanzee landmark labels

Currently learning chimpanzee FACS, chimpanzee anatomy, and making custom chimpanzee landmark diagrams. (Chimpanzee landmarks determined by Animal FACS group. Original research work by Lisa A Parr, Bridget M Waller, and Jennifer Fugate. See: Emotional communication in primates: implications for neurobiology )