Add In BlendShape target
Problem: having cartoony eyes, but it's not round, rather, it's squashed. Creating a wink or blink is such a pain.
Solution:
1. Model eyes in Lattice
2. model eyes in Half blink to support the blendshape 'add-in'.
Concept: "blending" the blendshape so that when the eyes blink, so it doesn't intersect with the eyes.
Steps:
1. Model a sphere, apply lattice deformer, any amount of S,T, U doesn't matter, but used it wisely, least is better. shape it to any stylish cartoony eyes you want.
2. model the head, the eyelids according to the shape of the eyes.
3. create a blendshape, let's say it's blink, duplicate the base head, and model the half blink.
4. So now we have the base head, the half blink head, and the full blink head.
5. Select the half-blink eyes, the full blink eyes and then the base head in order, then goto deform> create blendshape> option box.
6. under the target shape options, check the In-Between.
7. There you go, when you slide to 0.5, it will use half blink, because you only have 2 model to blend.
8. depending on your blendshape model, just divide 1 with the amount of blendshape you have.
Say, the client(again!) want to add 1/4 blink(they might!) into your finished model, creating the blendshape from scracth again would pain in the ass, so this is what we can do:
1. assuming we have full head, 1/2 blink head and full blink head. select the 1/4 blink head(of course, after you model it).
2. go deform>edit blendshape> add >option box.
3. depending on how many blendshape you've got, you might have to check the Specify Node, but if you only have one, you don't have to.
4. check the "add in-between target".
5. Target index mean :
If the blend shape deformer blends target object shapes in parallel (the In-Between creation option was off when you created the blend shape deformer), you can add the new target object shapes so that they work in series with one of the existing target object shapes. One quick way you can identify the appropriate value for Target Index is by looking at the order of the target sliders in the Blend Shape Editor (Window > Animation Editors > Blend Shape). Note that in the editor, each target object shape has its own target slider. In the editor, going from left to right, the Target Index value for the left-most target slider would be 1, the next 2, and so on.
If the blend shape deformer blends target object shapes in series (the In-Between creation option was on when you created the blend shape deformer), Target Index can only be 1 because there is only one target slider. In this case, you don't have to specify Target Index, but you do need to specify the In-Between Weight.
6. depending on what line your half-blink head is in the blendshape editor window, just put that into your target index(put number, not the name of the blendshape), and set the weight to something less than 1, usually I put 0.5
That technique works fine with me, but there is another solution of using joints or cluster. I'll try to use that in the next project and compare to see which is more productive and efficient.