The Blend Shape Control

Although the book, “Stop Staring: Facial Modeling and Animation Done Right!” , written by Jason Osipa was released for 5 years already, the setups method for blend shapes presents in that book is still thoroughly today. The great thing about Jason Osipa’s setup is multiple blend shapes can be controlled by the translation of X and Y of a 2D slider, which reduce the controls animators have to deal with. Furthermore, certain shape would not happen at the same time, such as smiles and frowns. When animators increase the effect of target shape A, they have to reduce the influence of target shape B. By putting two of those shapes on opposite ends of the same control, the amount of work can be reduced.


Multiple Blend shapes can be controlled by a 2D slider controller

According to the explanation of Jason Osipa in his book, the weigh of blendShape can be link with the translation of X and Y of a 2D slider by expression. As “Osipa” style blend shape controls become famous and popular, Judd Simantov, technical director of Naughty Dog, had written Mel script jsFacialWin for “Osipa” style which can be downloaded from Jason Osipa’s website. It makes Jason’s setup easy to create by giving us a GUI to create all the different sliders and we can link blendshapes into the sliders.

GUI to create all the different sliders and link blendshapes into the sliders.

Steps for using jsFacialWin to create slider controls and link blend shape into the sliders

1. Load the blendShapes into the GUI first; hit the “Blends:” button, select the Blendshape node you want to load into the GUI.

2. Hit “Add selected” button, all the target shapes of the selected blendshape node show up in the blends text scroll list (name your objects properly is very important).
3. In the case of suck and blow slider, Type “suck_blow” in the text field below the sliders in the GUI.
4. Click on the grey box in the middle of the C type slider. A slider will been created in the scene.
5. Select the pet_blendShape.right_Blow from the blendshape scroll list, load it into the top right side of C slider, by hit the blue button in the top right of corner of the C slider GUI.
6. Select pet_blendShape.left_Blow and load it into the top left side of C slider.
7. Select pet_blendShape.left_Suck and load it into the bottom left side of C slider.
8. Select pet_blendShape.right_Suck and load it into the bottom right side of C slider.
9. Test out the slider view.


Target shapes are link into the corners of 2D Slider by using jsFacialWin GUI

References for creating target shapes and blend shape control

Osipa, J. (2003). Stop Staring: Facial Modeling and Animation Done Right. San Francisco: Sybex Inc.
Osipa, J. (2008). Osipa Entertainment. Retrieved March 20, 2008 from http://www.jasonosipa.com/