Layered & Solid¶
Two ways an emotion reaches the rig. They differ in what an emotion is made of by the time it reaches the face.
Layered builds an emotion out of smaller expressions, a lift of the brows here and a narrowing of the eyes there, each arriving on its own timing, so a feeling unfolds across the face the way it does on a person. Solid plays one finished blendshape per emotion, the rig's own Angry or Happy, so what was sculpted for that emotion is what you see. Layered is the richer performance and the usual choice. Solid is the simpler one, and the natural fit for a rig built around whole emotion shapes.
The choice is made once per character, as Emotion Source on the Emotion driver, and it changes nothing about how an emotion is asked for: a tag, a Timeline clip or a call from your code plays the same emotion either way. The OneClick Wizard sets up Layered for a character it recognises, and Solid too if you ask it to, so the choice is yours to make after the fact, not a prerequisite.
Layered¶
Layered builds each emotion from expression recipes, each with its own weight and its own timing inside the emotion. This is the usual choice, and it is why an emotion arrives as a face doing several things slightly out of step and not as one pose fading up.
An expression with no timing of its own rides the emotion's envelope as it is. One with timing keeps its own choreography inside it, placed against the hold so it lands in the same part of the emotion however long that emotion runs, and it can never reach outside the emotion's footprint. Either way it moves at its own pace, so a gasp keeps its snap and a smile its ease whichever emotion is playing them.
What you author here is the expressions. Each one, a brow raise, a squint, the corners of the mouth, is yours to shape on your own rig in the Face Rig Designer, to whatever taste suits the character. Which expressions make up each emotion, how much of each, and when each comes and goes inside the emotion is authored by FaceCue and ships with it. So a layered Angry is your brow and your squint, arranged FaceCue's way. The designer's Emotion Preview plays the whole emotion for you as it will run, expression by expression along its timeline, so you can see what your shapes do inside it before a single line is baked.
Solid¶
Solid drives the rig's own emotion blendshapes directly, one recipe per emotion. If your character already ships with a good Angry blendshape, this uses it. It is simpler to reason about and easier to shape by hand, at the cost of the internal detail Layered gives you.
What you author here is the emotion itself, in full. Each named emotion is one recipe on your rig, and everything about how it looks is yours, in the same designer.
Which to Use¶
Neither is better. Layered suits a rig with a rich set of small expressions, Solid suits one built around whole emotions. A character set up by the OneClick Wizard can arrive with both maps filled in, so switching between them is a setting on the character, not a rebuild. By default the wizard creates only the Layered map: the Solid one is a picker on its Apply step, under Channel Maps.