CREATING A BLEND SHAPE WITH INBETWEENS (EYELID)
1- When doing a blink, make sure (if possible by the character design) that the eye lids rotation point matches the eye ball center. This way, the rotation will be clean and smooth,
2- Create a cluster for the upper eyelid by selecting all the vertices on the skin geo of the eye lid.
3- Do the same for the lower eyelid.
4- Create a locator for each cluster.
5- Parent constraint each locator to the center of the eyeball so the cluster rotates from the eyeball’s center. You can also change the cluster pivot point under the cluster attributes.
6- Create a timeline animation from frame 0 to frame 10
7- Key the locators in frame 0 wide open or in base position.
8- Key the locators in frame 10 with eyelids wide closed.
9- If the sides of the eyelids don’t fully make a contact, create a set of 2 more clusters for each side of the eyelids and center its pivot point in the eye ball. Rotate the locators driving these new clusters in a way that makes the sides of the eyelids close. Key the start and end state in frames 1 and 10 respectively.
10- After the animation is smooth and working, go to each of the following frames and copy the geometry to create each blendShape state (base, end, and inbetweens)
frames: 0, 2.5, 5.0, 7.5, 10. This will make a total of 5 geos (1 been the base and 4 that you just duplicated). You can translate them in world space to be able to see each separately.
11- Select the end geo first, then the base geo and create a blendShape using the default paramenters.
12- Now, select the first inbetween blend shape (taken from frame 2.5). Then select the base and go to “edit deformers”, “blendShape”, “add”. Define the name of the blend shape in the dropdown menu, and then, in weight, put 0.25. Hit create.
13- Then do the same for the geo taken from frame 0.5 and put a weight of 0.50
14- Then do the same for the geo taken from frame 7.5 and put a weight of 0.75
15- If using Louis voter’s “BlendShape manager”. Select the base geo, and click “base”. Rename the the additional 4 frames (2.5,0.5,0.75,100) like this:
Now Select them in the outliner and click “add” in the “blendShape manager”. Your blend Shape should be done.