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jedijrmax
11-22-2003, 10:51 PM
Hey guys,

I'm working on a school project, and I'm really stuck.

I have two problems.

1. The character has dialogue so I'm trying to make blend shapes for the different sounds. Ok, now this might be a little confusing but I'll do the best I can.

Right now I'm just doing a practice run before I touch my real character. But ok, I have a poly head with a few joints in it, skinned with smooth skin. The jaw joint, I painted the weights for so I can move it up and down nicely and have the mouth open and shut. Ok no problem. I have teeth that I parented to that joint also, ok no problem. So I move the jaw joint down so that he has his mouth open making the "AH" sound. I then duplicate that head so that position is frozen, then move the jaw joint back so that the characters lips are touching again and now we are back to squareone.... only now I have the new duplicated head, with the mouth open. I make that newly obtained shape a blend shape for the original...and it works......kinda......except for the fact that the teeth......do not move, with the jaw. Ok, that makes sense..........but what do I do? After putting the blend shape at 1, I try to just like, move the jaw bone and put the teeth in the right place but with the blend shape affecting the shape of the face at ".5" and then me moving the jaw bone for the teeth to go down....also affects the face............ how is this supposed to be done?

I hope that all isn't confusing.......but basically what I'm saying is......with a poly head rigged..........and blend shapes.....how do you get the teeth to move with the blend shape? because as I go to move the teeth......then the skinned head affects the specifically modeled blend shape.........

Please help........please!!!
Thanks guys.
Atwooki
11-22-2003, 11:07 PM
Start here:

http://www.dipaola.org/stanford/facial/assign3a.html

and if you want to invest more time in a seriously great book, get:

'Stop Staring', by Jason Osipa.... ;)

Atwooki
kiaran
11-22-2003, 11:14 PM
Could you use set driven key to connect the rotation of the jaw joint to all the blend shapes that require the jaw to be open? Then just parent the teeth to the joint. This might be alot of time to set up but I don't see why it wouldn't work.
jedijrmax
11-23-2003, 05:42 AM
Thank you for both of your replies.

I've been working like a maniac trying to figure this stuff out, and one of my friends from this site actually mentioned the same thing....using set driven key. I can't say that that thought never crossed my mind, but at the same time, I definitely didn't know that that was the way you are "supposed" to do it. And so I guess that I will be using set driven key for the blend shapes that require the mouth to be open and the jaw to move down.

As for that book Atwooki mentioned....one of my professors here at RIT actually mentioned that book......I'll definitely have to check into that. Although he made it seem as if it was very.....general.....perhaps talking about lipsynching and facial animation as theory, not necessarily anything related to Maya......although really...both would be useful.
MikeRhone
11-23-2003, 11:48 AM
Stop Staring Is a very advanced book. I wouldn't say its "general" but it is about 50% technical and 50% animation.

You should have a good grasp of aniamtion and some rigging knowledge beforehand or you may find it frustrating. After saying that though, that book has changed the way I rig characters forever.

mike R
MikeRhone
11-23-2003, 11:48 AM
Stop Staring Is a very advanced book. I wouldn't say its "general" but it is about 50% technical and 50% animation.

You should have a good grasp of aniamtion and some rigging knowledge beforehand or you may find it frustrating. After saying that though, that book has changed the way I rig characters forever.

mike R
Stahlberg
11-24-2003, 08:44 AM
My own way of doing it is to skip the bone for the jaw and make the open jaw a Blendshape. Simplifies life a LOT. I know the Blend is a linear movement, but the maximum error is only a few millimeters (the trajectory of the real jaw is quite flat). So it works fine, no one can tell the difference in actual animation. And if you're really anal about it you could add another transitional Blendshape in the middle.
djx
11-24-2003, 11:37 AM
I do the jaw with a blendshape, but my jaw blendshape-target is not a static shape; it has a cluster which animates it. The cluster rotation/translation can be driven by the jaw bone to which the lower teeth are parented. (Thus this blendshape-target's slider is left set to 1)
It is a bit more work to set up, but it has the advantage of being a blendshape plus it is able to be rotated and translated in several axes, which can be a real bonus for exagerated characature type animations.
MunCHeR
11-24-2003, 02:00 PM
Hi guys, yeah I'm having the same problem, I have looked at quite a few tutorials and received Maya Character Creation by Chis Maraffi today so I'm hoping some of the answers will be in there, the stuff I have looked at seems to assume that all the phonemes can be used with the face in its neutral pose.My character is a bear so obviously the jaw is mostly protruding from the front of the face more than a human character.I got some advice in an IRC channel to model the body/soft palette/teeth and tongue seperately which is what I have done but i can only envisage problems once I accentuate the shape with a slight jaw opening. And then theres the issue of the soft palette intersecting with my cheek geometry, and the tongue i guess would be best animated with some bones.I like Stevens idea of just using blend shape and forgetting a jaw bone, its would appear to be easier.Anyways i feel for you jedijrmax, hope we find a solution real soon so we can get on with our creating :beer:

Chhers MunCH
MunCHeR
11-24-2003, 02:03 PM
What the hell is a Chher??? See the trauma is already making me stutter, wonder if there will be work for a stuttering animator lol :eek:
jedijrmax
11-25-2003, 08:01 PM
Stahlberg,


I understand how you say to make the opening of the jaw just with a blendshape....but if there isn't a jaw bone to parent teeth to, and the bone to move the teeth along with that "opening jaw blendshape" then how would you go about moving the teeth?
Stahlberg
11-26-2003, 04:26 AM
Just parent the teeth and everything else that has to move with the jaw into its own group and make it rotate in tandem with the Blendshape, a simple SetDrivenKey will do it. Or you could use a bone just for that group.

Note that the pivot point (or joint, if you use a bone) has to be behind the ear, almost out the back of the head, to get realistic motion, since the real jaw-hinge isn't a simple pivot but also drops a bit during it's arc.

(edit: in fact the arc seen from the side is J-shaped, not C-shaped, so even a totally bone driven jaw will not behave 100% realistically...)
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