View Full Version : solution arm-shoulder problem

10 October 2003, 08:39 AM
solution arm-shoulder problem
Has anybody found a nice solution for the eternal arm-shoulder problem yet?

I tried rigs with combinations of hold bones, Metaeffectors, spherizes, muscles, flexmotion(in the armpit), flexmotion on the shoulder/arm link, softbodies, auto HP for the shoulders, angle driven morphs for +-heading and -+pitching. The last and most oldskool way still worx best, though it takes most time to set up(life sucks).

Results are not bad but they don't work for any pose. Especially when I start to bank the upperArm or when trying to touch my opposite shoulder. But its still not satisfying enough.:banghead:

U see, my character is built up out of water. So I need a metaball(hypervoxel)ish blending look at the joints.

I think I've tried everything.
Could someone help me out please (or not?).

10 October 2003, 09:03 AM
What people see, apart from the animation, are the deformations!
They don't give a fak about messiah or motionbuilder or ... whatever. And even less about its features.
Nice, natural deformations. That's important and very hard to achieve.

10 October 2003, 09:15 AM
Shoulder deformation very much depends on your geometry flow - look at Tarons butch sample scene and see how beautyfully the shoulder deforms with just a basic skeleton - when the model is done right you might get away with very little or now extra solutions. I've gone through all this myself, and I usually always come back to the simplest solutions. Also, always remember that the clavicle contributes very much to the arm movement, e. g. when you try to touch the opposite shoulder, the clavicle moves foreward, wich compensates the extreme crease. When the arm moves up its movement anatomically is pretty much limited at the horizontal, from there the clavicle begins to raise. For banking the arm at the shoulder simply split the upperarm bone and bank the second upper arm bone, not the one at the shoulder itself (or at least not that much) - again, when you look at your own upperarm, it actually doesn't bank right at the shoulder itself. So, shoulder deformation rarely occurs just on the shoulder joint itself, and with these things in mind you should avoid the extreme deformations... Still, it's a tricky spot, I agree, and it takes much experimentation to get it right :)

Hope this helps a bit...

10 October 2003, 09:16 AM
In all cases, the key to proper deformation is your geometry.
If your geometry doesnt help, messiah wont save you, nomatter the promising name.

10 October 2003, 09:50 AM
Thanx guys.
When I I compare my model with that butch guy, my deformations also look pretty well.
Maybe Im just too hard to please.:annoyed:

CGTalk Moderation
01 January 2006, 10:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.