
The blends worked well except that they did not follow the influences of the skeleton that the model was bound to. If the Rex's mouth was opened and I "morphed" his face into an angry expression, his mouth would close. Should that happen? I think that the blend shapes should follow the deformations caused by the skeleton but I don't have enough experience to know for sure.
One thing I can think of is that I created the blend shapes (copies of the head) before binding the model to the skeleton. I also "un-bound" the model several times during the rigging to adjust the skeleton.
Any thoughts?