Game Development Reference
In-Depth Information
eventually you could reach your limit. Even so, this can be overcome through clev-
er use of your shapes; you can mix existing ones to create new ones.
The initial setup of the joint-based face rig can be quite cumbersome and tricky,
since you're having to use Set Driven Key to store each pose and area of move-
ment. However, once they are complete, redoing them shouldn't be necessary,
even if the character's topology is changed.
The blend shapes setup is simpler but does rely heavily on the main face's geo-
metry being locked. Any alteration in the facial topology could result in your hav-
ing to redo all the existing blend shapes.
With the joint setup, you can't get the facial expressions vertex-perfect, because
each vertex's position is merely influenced by the joints. With blend shapes, on the
other hand, you are physically sculpting each face, allowing you to get each pose
perfect.
If you are lucky enough to be able to choose either method, it will come down to your own
preference or style of working.
Summary
This chapter's discussion of the use of joints and morph targets to achieve facial animation
will help you decide which one you prefer and which is appropriate for your project. Next,
we will move to the chapter on the final binding—attaching our characters' geometry to
their skeletons andthenadjusting theweighting information toenable correct deformation.
