Here's a short How To, I hope could be of help to someone who'd be interesting in learning how to set up a 3D model for lip synching, or any kind of dialogue animation in 3Ds Max. I'm sure that this could be useful in other 3D applications as well. This is kind of what you can end up with:
When you've completed a 3D model that you want to to be able to animate with facial expressions, and have a character's mouth animate along with a dialogue. One way that you can achieve that kind of animation is with the use of a Morpher modifier. I'm going to explain the process of setting one up, don't worry, it's very simple!
This is an example of a completed head model, it could be textured or not, it's entirely up to you. From this point, you won't be able to do much animating to it's facial expressions or do an lip sync. Why? That's because you have to apply a morpher modifier on the the main head model. Next, you'll be making copies of this head model...
The amount of copies you make, depend on how many mouth targets, and facial expressions you'll be needing for your animation. One for a smile, another for sad, another for narrow lips, another for open mouth, lower lips up, lower lips down, etc. The amount of positions you'll make entirely depends on what you'll need for your animation. Don't be afraid to do a lot, with the morph modifier, you can also animate the eyes blinking, the eyebrows in up and down positions and more.
Once your done making your copies, and altering them for to make each expression. You have to set them up in the morpher modifier for the main model. See the glowy area in the picture above? That's where you will go one by one, selecting each of the copies you made earlier. If you look closely, you'll see there's one for a smile, narrow, frown, upper lip up, etc. etc. Each of those are the key positions that you'll be using! Here's the fun part!
Using those key positions, you can turn on auto-key, and begin animating! Just like that! You can mix two different key positions to create a plethora of different expressions an mouth movements, that are sometimes silly, and totally not what you expected.
If you have an audio dialogue that you want your animation to sync up with. You can import the audio into the timeline, and use the scrubber to slowly play the sound, and listen to each word in the dialogue as you go along, and try to match up each mouth position with the words being said. You'll have to keep in mind the different mouth targets for each word. I really suggest, that you keep a mirror in front of you as you work, to try and match up how your lips move when certain words are spoken. Then, use the mouth targets to animate each phoneme. I hope this short how to, could be helpful to someone! If there's any questions about this or anything let me know!