I got a rig that originally was created and rigged in lightwave. I found someone to convert it to mb so I can import it in Maya. The rig was imported into Maya as a single whole mesh (no different parts/pieces) and with a rig/joints skeleton. The default skeleton rig/joints that came with the mesh covers only a few basic body parts (e.g. head movement, limbs movement). It does not cover any of the lips, tongue or jaw movement. If I attach extra joints on them (edit influences and paint the weights) all they do is to stretch the skin. They are ineffective to actually move the lips appropriately or open the jaw.
I believe that if the rig would come as pieces into Maya, then a simple parenting with the joints in the outliner would be enough to make the jaw, tongue and lips move. Now it is impossible as it is.
Might you know a way to fix it?