One of the most essential tools in a rigger’s toolkit is blendshapes. Blendshapes are deformers that allow an object to change its shape based on the shape of a duplicate. Simply put, it’s a way to get your object to change its form at will to look like something else. Some basic examples of where you could use a blendshape are blink attributes for eyelids (the original mesh would have the eyes open, and the duplicated mesh would have the eyes closed), or even the squash for a ball (the original would be the ball object, and the duplicated mesh would be the same ball in a squashed shape).
The workflow for creating blendshapes is quite simple:
- Duplicate the original object you want to alter.
- Edit the duplicated object to get the shape/look that you want.
- Connect it back to the original object
- Select the changed object
- Shift + select the original object
- Go to the Rigging menu dropdown > Deform > Blendshape > Option box > Create Blendshape
Blendshapes can be used for a variety of cases in which you need specific control over certain parts of your object, such as facial rigging, corrective deformations, and muscle/skin controls. For more information on the characteristics of blendshapes, how they work, and how to apply them, check out this video clip on the basics of blendshapes by our Intro to Rigging instructor, Eriks Vitolins.