Facial Animation
- This will not be a walk-through tutorial like the past pages have been. Instead, it is more of a Tips-N-Theory page dealing with how to accomplish facial animation in MotionStudio.
   
  First, why do facial animation with bones in MotionStudio?
Here are the reasons I came up with:
 
  • Body and facial animation on a single mesh
  • Quicker setup - no need to build 40+ morph targets
  • Facial movement in arcs as opposed to linear interpolation of vertex blending (especially useful around the jaw area)
  • Easy to add new poses (expressions, phonemes, etc.)
  I was also inspired by the Cane-Toad face rig. Go here for more info: http://www.cane-toad.com/tuteRig_Facial.htm


  The problem I ran into initially was getting the bones to be "flexible". My first attempts involved using two or more bones for each "point" so that I could get the proper extension - especially important for the lip areas.

Using two bones
  This does give more freedom to move the end point in/out/around but the distance is still limited by the length of the two bones.
Another thing I tried was to use four bones, in an "M" shape. This gives a bit more "elasticity" but the rig gets cluttered very quickly.
 



  The next thing I tried was to use multiple skeletons for each bone/node in the face. This gives you the ability to move the attached sub-skeleton bones in any direction, but it was just way too wonky since everything was on its own skeleton so selecting individual parts was a nuisance. Also, pose mixing was out of the question with this method.
 
  Enter the Humdinger...
 
I emailed a fellow MotionStudio enthusiast, Vinny (Humdinger) Carvalho, about how to incorporate "floating bones" for facial animation. Sure enough, he knew of a way to do it.
 

Here are the steps Vinny outlined for floating bones:

- Add Skeleton
- Add Joint
- Add Bone

  You should then wind up with something like the following:
 

Although the second bone has complete freedom, it is still part of the same skeleton.


  Putting it to use
  Armed with the knowledge of building "floating bones" rigs, I started experimenting.
 
 
Download this scene
 
See it in action


  Other uses
  Morph targets give you ultimate control over smaller details like skin creases since you make adjustments at vertex-level (this too can be accomplished using only bones, but it would take more thought and precise setup with more bones than used in the above example)
...so some folks may wish to stick with morph targets. HOWEVER, you can use a bones face rig to quickly generate approximate facial expressions, save the mesh, and refine it further by manipulating the vertices.
   

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