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View Full Version : Deforming Skin/Fat/Wrinkles on an Organic Character with Underlying Musculature/Skele


usernamelolorz
12-05-2006, 05:09 PM
Hi! I initially posted this to the modeling section but was told to post here too.

The characters I build end up like stiff statues - I need to understand what kind of materials, software programs, plug-ins, effects, dynamics, and other tools/utilities/packages might give their skin, muscles, fats, skeletons, etc., all interconnected and organic properties, so that they are all distinct components of the character affecting one another in a natural fashion. If you have any general ideas on this broad question, feel free to say anything helpful.

One goal: I'm trying to build a character with "rolls" of fleshy material that change dependant upon action and expression. For example -
Imagine the forehead of an old man; when he frowns or smiles, his wrinkles bulge and press against one-another, while sliding over the curve of his skull. But if his face relaxes, the skin would be almost smooth, except for the creases in his skin - there would be very little of "bumps".
Or think of the nose of a cartoon dog - when he smells something interesting, it might bunch up like a wrinkly accordian along his snouth, gathering in fleshy lumps.
Or look in the mirror and smile - when you smile very big, you may get dimples, or bumps at the corners of your lips that sink into your cheeks, etc., etc. But you notice that your fat and skin slide along your jaw bone, your cheek bones, crease your eyelids, etc.
As you can see, it is important for the sake of an organic look that the skin and musculature of a creature/character are dynamic - that bumps, lumps and wrinkles are capable of growing and deforming, muscles are able to stretch or compress, skin can be relaxed or pulled tight, wrinkles can compound, etc., etc. I am terribly baffled by the prospect of turning a simple model into something so alive - I don't know how to begin doing it.

If I do not want to use blendshapes to model wrinkly and non-wrinkly forms and switch between them, what should I be looking into? Or are blendshapes the only real solution? What would Pixar, Dreamworks, Disney, ILM, et. al. do to achieve this - would they use blendshapes or something else? I would prefer a professional-level solution if you know of one; not a "cheap trick" -- it must be capable of comparative quality to a feature-length animation, it must not look like a video game. Feel free to recommend all sorts of expensive software packages if those are really the best solution; I'm willing to save up for them.

Thank you!!!

pooby
12-05-2006, 10:35 PM
There are numerous ways of doing these kinds of effects.
Many people ask 'should I use a bone facial rig or morphs?' well, it seems to me that its not really an either/or situation. You can use bones, morphs, curves, constraints, lattices, etc - whatever to create the effect you want.
Curves are great on faces, because (in XSI) you can envelope (skin) them to bones, and have your deformers constrained to a percentage along the curve, you can then add morphs to the curve itself as well as the mesh, and constrain curve points to other curves creating a network of 'muscles' under the skin that will slide and stretch naturally with any movements in one area of the face. You can then link these movements to morphs in the geometry to bring up wrinkles when the face is in certain positions.
The main thing with rigging is to get to know your packages tools really well then experiment with them to see what you can combine to invent new techniques.
It's hard, without seeing what you are currently doing, to suggest a way forward, but I think the key is always experimenting and thinking to yourself - I have this tool and I have that, what happens if I make this one control that..etc..

Read the facial rigging thread in the rigging section.

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