question to advanced MAX user: how do to rig/skin shoulder?

[drifter51]

Are you wieghting the vertices individually? or just using envelopes?

maybe post a wireframe of the shoulder in question so we can see how you placed your loops. Might be a design issue as well.

[CapnPanic]

another recent thread on this subject:

http://www.cgtalk.com/showthread.php?s=&threadid=56271

[neversong]

thnx guys.

here's the screenshot of my model.

as you see, this guy has very very thick shoulder.
what happens is, that thick shoulder twists so terribly.
so, just wanted see if there's any advanced way of dealing with this kind of thick shoulders. (or any thick joints)

as you see, bending downwards is ok.

but, If I raise the arm, then it's crazy.

check this out (http://damascus2.com.ne.kr/see.jpg)

:rolleyes:

[drifter51]

What position was the arm modelled in?

The up position in the image should be the position the arm is modelled inorder to get the maximum movement range with the least twisting.

Do you have a bone for the clavicle that the shoulder bone connects to? In the image it looks like nothing past the shoulder is moving. Don't forget that the neck and shoulder blade muscles are moving as well, especially the higher the arm goes.

[xynaria]

Be nice to have a screen grab with the bones in place.. but from what I san see the construction of the shoulder at the back doesn't look helpful. :)

[neversong]

thnx guys.

is there any advanced way of skinning for muscular character?
anything that's useful to know?

by the way, here's a front view with the bones.

here (http://damascus2.com.ne.kr/see2.jpg)

I also see some problem with the mesh structure.

it's still not that bad but doesn't look good.
what was I thinking??!! :shame:

thnx again.

if you guys know any nice tutorial or any knowledge on advanced skinning technique, please share with me.

[xynaria]

Is the pic showing there the pose you used for skinning?

Generally it is said that when you rig a character you do so with arms outstretched like that at 90 degrees.....however I don't myself neccesarily think that can be taken as true for all cases.
Whilst in theory this gives the most latitude for up and down movement... it isn't always conducive for possibilities on how you construct the mesh for what kind of detail and approximation you might have of musclature. Expecting a mesh to deform arms at a full 180 degrees and look muscularly feasible on the chest and shoulders by bones alone is one hell of a tall order.
BUT... do you need to... in many cases no.. its not often the case you are going to want the character to have his arms outstretched fully upwards for intance. At the moment I'm playing with rigging with the arms down at 45 degrees because of the way I want it to deform the chest but I haven't got time to play on it further for a few weeks but that might be worth considering if you haven't already.
On the prevous pics having his arms outsretched made him seem a bit disjointed..... especially from the back .. but that is because of the way the mesh is constructed I think.. the level of the shoulders is already raised quite high for the torso.. even on the shots with the arms down...Even you are not muscular look at your own body because bone structures don't vary that much in their overall construction.

Also ..read the thread Capn_Panic refers to ..theres some very helpful tips in there. :)

[neversong]

thnx, xynaria

I've seen a lot of people modeling characters with the arms pointing 45' down.

I've always been wondering how much different/effective that way is compare to 90'.

and, I think, you pointed out really well about the shoulder position. Thank you, it really helped.

as I was modeling it I didn't know, but now I can see how it is.
This model was my third character I've ever modeled. (I'm working on my 4th thesedays.)

personally, I want to ask you if you'd recommned character studio instead of normal bones. I see some cons/pros about that.

thnx again, guys.

;)

[xynaria]

Yeah ..it's so easy in modelling to get used to seeing your model.. not what its refering to and doing that double take is not always easy. :)
Personally, I only use CS if I have to but then I've mainly been honing my modelling.. and am now upping my rigging skills at the mo. I've not used it enough to have a valid opinion on it...I've heard good and bad about CS.. horses for courses.. all depends on what your doing and the time frame..

[sam]

The bottom line is there is no way you can get a perfect solution to a shoulder with skinning alone. Skinning tends to make things look like gumby all stretchy and pliable. But human muscle is complex and difficult to simulate without something like a muscle system.

There are a few tricks you can try.

One of the issues with shoulders is that its pretty much impossible to have a single pivot point and simple skinning correctly handle the whole shoulder well, either you get a pronounced caving in under the armpit effect or a pronounced strange deformation (bulge or collapse) of the shoulder. The two problems are in sort of a seesaw relationship, as one gets better the other gets worse, all depending on where you place the pivot point.

One possible avenue would be to rig a character so the shoulder has more than one pivot point driving the shoulder muscle masses. Basically just make a bone chain running off the clavicle so that it hangs above the normal shoulder joint and use orientation constraints to keep the bones where you want them in relation to the normal shoulder joint moving around.

Otherwise the basic approach would be . . . basically you rough in the skinning job and progressively fine tune the trouble spots.

You should try to get as much mileage as you can with envelope placement and then work on vertex weights to fine tune areas. Make sure to correctly place the clavicle where it would anatomically go so you can use it to move the chest area when the arm goes above the head.

Physique has tendons and bulges which can be used to correct areas even futher. A tendon going from the arm to the chest can help correct the collapsing or bulging chest problem when the arm is raised.

Physique also allows you to add floating bones and these can be combined with wire parameters to give you precise vertex level control over the skinning.

Also, you can use morphs to help correct an area provided things aren't too messy when you get to this point and you want to add that little extra bit of perfection. You have to look at your base mesh and then your mesh in a pose and correctively apply a morph to a copy of the base mesh so that it will fix the mesh in the pose and then use the reactor controller or a wire parameter or an expression to hook the morph channel to the joint rotation.

Anyway just some ideas for you to chew on.

sam

[robert east]

also another area to consider is where your shoulder rotation comes from , ive seen a lot or rigs built that just give people problems because when you reach forward its not just the arm moving its the whole shoulder blade and front muscles in the chest , just look at your own arm/shoulder as it all moves forward ,
in xsi/maya you can script this all to be automatic , not sure about max , but go to softimage.com , under the tut section , you will see a tut on what im on about , it will help with your whole shoulder problem .

regards rob

[Airflow]

I think your talking about an auto clavicle.... basically the clavical is part of the hinge that lifts the arm, I tend to raise the arm by animating the clavicle, but you can script, wire or set up a reaction to make the clavicle rotate whne you raise the arm...

[MGernot]

Also, you can use morphs to help correct an area provided things aren't too messy when you get to this point and you want to add that little extra bit of perfection. You have to look at your base mesh and then your mesh in a pose and correctively apply a morph to a copy of the base mesh so that it will fix the mesh in the pose and then use the reactor controller or a wire parameter or an expression to hook the morph channel to the joint rotation.

Anyway just some ideas for you to chew on.

sam

Yes, just use SkinMorph for that. No need for complex reactor controller- setups.With it you can pretty much fix everything.

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