Fitting the Face
It’s time to fine-tune the placement of the controls and curves that were created as a result of the solving process. At this stage, you can adjust and fit the controls for specialized parts of the face that include the eyes, the jaw curves, the jaw bone, the neck spine, and the tongue.
If you accurately picked the landmark points in Stage 3: Landmarks, you shouldn’t need to adjust these controls very much - just do a bit of tweaking to make everything perfect.
To see videos on this topic, check out Tutorial #2: Adjusting the Fit and Tutorial #3: Testing the Solve on the Face Robot Learning Movies page on the Softimage wiki.
To fit the controls on the face
1. Select the element you want to adjust from the Adjust list.
The appropriate elements on the Display list are selected automatically. These are the element controls that you want to display on the face for each adjustment area.
You can also select more items from the Display list, or deselect others, as you like by toggling them.
2. Select and move the controls on the curves until they accurately fit the face and head. See the following sections for information about each area:
- Adjusting the Curves
- Adjusting the Eye Controls
- Adjusting the Jaw Bone
- Adjusting the Neck Controls
- Adjusting the Tongue Controls
Creating a Solved Head
3. Select the Type of animation that you will be using for the facial animation: Keyframe or Motion Capture. This optimizes the solver for the particular type of animation in terms of how the neck is built:
- If you select Keyframe, the head follows the neck base when you move the head controller.
- If you select Motion Capture, the neck base follows the head when you move the head controller.
4. Click the Solve button when you’re done fitting.
Face Robot computes the shape of a human face model based on the position of the controls and a set of soft tissue parameters. This algorithm processes the skull geometry and the soft tissue model to generate an animation control setup for the head.
The calculations required for this process take a few minutes.
If your face mesh is very dense or if the mouth cavity has the tongue, gums or other details modeled into it, it can cause this part of the solve to take longer than usual. You can speed up the solve by selecting the vertices associated with these details and putting them into a cluster named “IgnoreMouth.” If this cluster exists, the solve will not take these vertices into account.
This is also a good way to troubleshoot imperfect mouth solves. If the geometry is more complex than usual, or if the mouth is modeled in an unusual way, creating an IgnoreMouth cluster can help Face Robot to focus on the parts of the mouth that are important for the solve.
Testing Out the Solved Head
When the solving algorithm is complete, you should test out the head’s movements to make sure that the face deforms the way it should.
For example, if your character’s mouth remains sealed when trying to open it, it’s usually caused by the solver not having a good enough sense of the facial construction of your model.
If you go back to your Fit scene (pre-solved), you will notice two ear clusters have been created on the mesh (LEarCluster and REarCluster). Each cluster should accurately contain all the points of their respective ear. This tells you Face Robot is building an accurate representation of your head for solving. If the correct points are not selected, simply add or remove points to the clusters until the proper area is selected. Do this for both ear clusters and resolve your head. The mouth should now behave properly when opening.
After you’ve tested the head’s movements, and you’re happy with the solved results, go to the next stage:.
Adjusting the Curves
You need to adjust the controls on the face to make the curves fit the face’s jaw contour as closely as possible.
For faces that have more flesh around the jaw area, you may want to adjust the middle jaw curves so that they are a bit lower on the face. This can help to make the fattening and jaw tuning in Stage 6: Tune more accurate — see Tuning the Jaw for information
1. Select Curves in the Adjust list to see these controls and curves displayed:
2. Select and move the sphere controls on the curves until they accurately fit the face’s contour. Drag the appropriate axis handle on the manipulator to move the control in only that direction.
- Move the controls on the left side of the face to adjust symmetrically. Mirror symmetry is activated so that both sides of the face are adjusted at the same time.
- Move the controls on the right side of the face to affect only that side.
Activate snapping on the Snap panel in the main command panel to have the controls snap to the points on the face's surface for a nice, snug fit.
Adjusting the Eye Controls
1. Select Eyes in the Adjust list to see these controls displayed.
2. Select and move and/or rotate the red spheres so that the centers match the pupils in the eyeballs and their position matches the position of the eyeballs.
Adjusting the Jaw Bone
1. Select Jaw in the Adjust list to see these controls and the jaw bones displayed.
2. Select and move the yellow boxes so that they fit the chin, the corner of the jaw, and the cheek bone.
Adjusting the Neck Controls
1. Select Neck in the Adjust list to see these controls displayed.
2. Select and move the yellow boxes so that they fit the top of the neck (where the skull meets the top vertebra) and the bottom of the neck (where the neck meets the body).
Adjusting the Tongue Controls
1. Select Tongue in the Adjust list to see these controls displayed.
2. Select and move the orange nulls so that they fit inside the mesh for the four parts of the tongue: the tip, the front, the back, and the base.
If you’re doing lip-synching, it’s important to have these controls placed as accurately as possible. The tongue tip is crucial to certain making phonemes (language sounds) look correct, such as for “L” and “TH”.
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