1. Chapter 7: Getting Bent Out of Shape: Blend Shapes
Maya 2014 Essentials
Chapter 7: Getting Bent Out of Shape: Blend Shapes

2. Maya topics covered in this chapter include the following:
Understanding Blend Shapes and How They Work
Creating Deformers for Your Character
Setting Up the Blend Shape Interface 2

3. Blend Shapes Copies of your main geometry, slightly altered
Used to create facial expressions:
Blinks
Eyebrow raises
Smiles
Frowns…
Deformers, known in Maya software as blend shapes, change the surface topology of your model in ways you can mix, match, and control. 3 3

4. Deformer Order Deformers applied in order created
Maya uses multiple types of deformers to alter your model’s geometry, and the order in which those deformers are
applied makes a difference.
Deformers applied in order created
Later deformers override earlier
Blends & skeletons both deformers
Blends done first
Can be reordered, but easier to create in correct order
It’s possible to reorder the deformers, but it’s easier to create them in the right order in the first place. 4 4

5. How Blend Shapes Work Each vert in model has a unique number.
The verts are numbered in particular order.
Blend shapes compare position of verts, adjust position relative to vert’s position main model.
DO NOT add or delete geometry after creating blends – blends won’t work.
Make any changes to geometry before making copies for blends 5 5

6. Planning Your Blends List expressions you’ll need
Break down into small changes:
Mouth corner up
Mouth corner down
Eyebrow outer up
Eyebrow middle up
Eyebrown inner up
Etc…
In general, blend shapes work best when they’re not trying to do too much.
Typically, you make blend shapes that focus on moving one small aspect of the facial geometry rather than trying to create an entire expression at once. 6 6

7. Creating Your Blends Select base model
Choose: Select Edit>Duplicate
Move copy. Rename w/name of blend 7 7

8. Creating Your Blends Select verts on copy to change
Make adjustments, Rename it
(For example: mouthCnrUpLt)
Example of Names: mouthCnrUpRt, mouthCnrDnLt and mouthCnrDnRt. 8 8

9. Creating Your Blends
Continue creating copies, making changes 9 9

10. Creating Blend Interface
After creating all blend shapes, create the blend shape interface that will allow you to apply one or more blends to the main model.
Shift/select all blend shapes one at a time
Select base model last 10 10

11. Creating Blend Interface
Switch to Animation menu set
Choose: Create Deformers>Blend Shape 11 11

12. Using Blend Interface Window>Animation Editors>Blend Shape
Blend shape sliders apply blends to base model 12 12

13. After you’ve created your blend shape interface, you can delete the blend shape models from your file, and the blend shapes will continue to work. Be sure to save a copy of your file containing the blend shape models in case you need to make changes.
You can add new blend shapes after the interface is created. Create your new blend shape from a copy of the Base model, as before. Select that new blend shape and then the Base model, and then choose Edit Deformers  Blend Shape  Add.