Rigging gums & lips: How do you do it?

[archanex]

What do you need it to do? and Why are you unhappy with your current solution?

[Valtiel]

Ideally, I'd like the model to represent the entire face connecting to the upper and lower gums including the inner walls of the cheeks and lips. As for the rig I'd like it to let me manipulate the soft tissue geometry in any which way you can push and pull it around so I only need to apply minor modifications for each operation instead of doing massive rebuilds. Facial expressions aren't too important to since it will be for medical context. The back of the mouth can be simplified or outright open edges. I don't think any of the operations we'll animate involves anything behind the wisdom teeth.

As pleased as I was with the old one (I'd never made a rig that complex before) it felt excessively meticulous. I was making a controll spline for every 2nd or 3rd edge loop to get the forms I needed. The only deformation techniques I know are morph targets, skinning objects to splines, point helpers, and other geometry with a bit of play in skin morphs. There's gotta be different ways to do it. Plus that rig is only particular to that upper labial frenectomy, I can't reuse it for any other operations in the future.

I'm interested in simpler positioning and shaping of the rigs that achieve the flexibility I'm looking for with fewer controlls to tweak for each key. Essentially a smarter rig over brute complexity.

For my own experience and education, I'm really keen to learn different, hopefully more advanced rigging techniques and this seems like an ideal project to learn on. Particularly if someone can help me get into muscle systems or other volume-oriented rigging. One of the ways I can think of to simplify this kind of rig is to controll the essential lip and cheek points without fussing about making sure the inner and outer walls don't crash through each other. I'm a bit lost on how to do that though. FFD? NURBS patches as controls?


So to sum up that big tirade. I'd like to build the new rig...
- To have control over the whole mouth, including inner lip and cheek structure, so I can reuse it for many operations with minimal modification to particulars like incisions.
- I'd like to simplify the geometric control structure, particularly keeping the inner and outter lip/cheeks from crashing through each other without having seperate splines for each. I'm keen to replace geometric complexity with scripting if possible.
- If I'm reaching out for community advice on this I'd like to learn as much as possible in terms of new techniques and philosophies in rigging that are relevant to the project's nature.

Hope that didn't sound too convoluted or demanding, I have a bad tendency to do that.

Cheers.

[archanex]

"As for the rig I'd like it to let me manipulate the soft tissue geometry in any which way you can push and pull it around so I only need to apply minor modifications for each operation instead of doing massive rebuilds"

I think that's the biggest thing, it sounds like you want it to do EVERYTHING, if you limited what the rig could do to just what you needed for one project I think you'd have a much easier time than trying to create one uber rig that does everything.

I think it's safe to say that any rig that does everything is going to be a lot of work. That being said, if you want to try a different approach, Jason Osipas book "Stop Staring" shows you how to get a wide range of facial movements with some well constructed morph targets

Another option is Paul Neale has some DVDs on facial rigging you may want to invest in.

Sorry if that's not the answer you were looking for

[daraeill]

I second the Paul Neale DVD's...very informative and setting up a bone rig for facial animation offers a huge amount of flexibility.


try this for the set, or you can bvuy each DVD individually. http://cg-academy.net/pages/topic_rigging/dvds_rigging_intermediate_boxedset/dvds_rigging_intermediate_boxedset.php

[Valtiel]

Thanks guys. I'll look into those. Paul Neale's DVD's look like they can get me started into scripting. They seem like they focus more on full facial expressions than I need for this case but there's no harm in learning that too.

I guess I've got two more elemental questions now.

1: In any context where you have an inner and outer wall of something organic, like fabric or flesh, to rig, are there any strategies to rig any one point in the volume and keep them from colliding without setting up two seperate controllers (one for each surface)?

2: When you have a rig and model that you need to make a minor modification to, like a few new cuts in the geometry and 2 or 3 new controllers to handle them, what's the most non-destructive way to go about it? What should I keep an eye on to ensure I don't have to completely rebuild the setup?

Thanks for your time, eh.

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