How to rig a shoulder ?

[tom schuelke]

Hi you talented guys here in the forum.

Well i´ve got a problem. I am still very much a beginner in rigging Characters.

At the moment i´ve got the problem, i dont, know how to rig correct a shoulder.

What i want to achieve ist, that the "clavicle ?" goes up automaticaly, each time, the arme goes higher but horizontal.

Is there somewhere a smal very easy way, tutorial, or does this mean heavy scripting.

My standart rig is based on CAT, but as i know, Catrigs can make use of every standartcontrolers you want.

so any standartsolution also with Max-bones would help..

Tom

[Morbid Angel]

ughhh rigging....not my cup of tea. But I have done some. There are several ways you can do this. I think the most simplest one is to make skin morph targets. Basicly the idea is to have two meshes one in the position A where shoulder is relaxed and second in position B where shoulder is where you want it with clavicle bone in the correct place. Then this is connected in skin morph I believe as a target for the bone. So when ever the bone moves that direction it blends between position A and B. I think you should look up in help about these.
have fun.

[tom schuelke]

Hi Morbid Angel,

thanks,

Yes of course, i also thought of this solution, and maybe it´ll be the only way for a beginner and no veteran sitting next to me..

well, but what i´ve seen, for example is those interisting rig of maxime, that comes with max.

there the shoulder bone moves up automatically after lifting the arm above a certain amount.

i considered for sure also to use skinmorph tarkgets, but only after the overal skinning is as good as i could acheave it with floating stretchy bones and much finetuning in skinweights.

problem only is, in 5 days there has to be a first 10 secound previewanimation ...


argh.


Tom

[joconnell]

Hi Tom,

there's four things that you need to do to make this work correctly.

First of all as you mentioned have an auto clavicle that will raise once the arm gets above a certain angle (since most of the time no one bothers animating it as they should). You can do this with either expose transform or using expressions.

Second of all you need to add in a stretchy muscle bone with an end bone that goes from the center of the chest to the front of the shoulder joint to simulate the chest muscle - otherwise you'll have a load of problems with your skinning and trying to get nice deformations.

Third you need to add another stretchy muscle bone from the middle of the back up to the rear of the shoulder joint in the same way as above to act like the scapula.

Lastly you need a stretchy bone from the side of the neck that points down towards the joint of the shoulder.

You need all these if you are trying to do a particularly realistic character or if your character has a lot of bulk - otherwise you may find problems with the mass of one part of the body going through another.

I should be able to get a small sample scene done up today and get it over to you.

[re:FORM]

Interesting.... I'm having similar problems and would love to see your setup with these stretchy bones.

[tom schuelke]

Hi Joconnel,

Wow, as so often told, this forum is realy a great place, no other place wherey you find so fast so good help.

Now, ill show you a short animation of the setup right now..

underlying rig is a catrig.

I allready have constructed a bunch of floating bones, where i think they could help.

also at the hip i constructed two (four later on) secoundary bones like in maxine in the max examples, to get better deformations here.

i also considered to use Cat-muscle as a skinning help, but i think getting it work on my own is the better way to learn it.

at the end, this character will have to do lots of realy extreme poses, so the rig has to fit this, and also skinmorph will be nescessair i think

http://www.tom-schuelke.de/forum/Eva_rigg.avi

tom

[tom schuelke]

Ah by the way...

I got problems to copy these stretchy bones to the other side.
I try to mirror them but get strange results.

i did reset stretch oneach bone, but i think, the dummys and constraints are the problem.


setup is, a dummy at the end of each floating bone, allined to the bones, a look at to the dummy at the top, and position constraints to the dummys.

dummys then can be linked to wherever i want..

(its the setup from the cg-academy learningtutorials skinning intermediate rigging 3...


Tom

[roppin]

here is a rigg of an axel I did to lern my self with some stretchy muscles etc. not that acurat but anyway an Idea. Hope it can help. for the automatic part; thats not my cup of tea. But I dont think it is that automatic. you can move your arms forward an let the shoulders stay, or even push them backwards. So I have a controle point for the movement of the upper arm joint.



here´s the file: http://www.idigalleri.org/stretchy_axel01.max

[tom schuelke]

hi roppin thanks for this

at the moment i still have to do many weightpainting untill i see if my floating bones... muscles allready are enough.


ill keep this thread up..

tom

[ene.xis]

don t know if it s too late but when i saw this i rememberd imediately this thread....

this is posted here:
http://forums.cgsociety.org/showthread.php?t=360924