Yep. You can't get around stretching, you can only manage it effectively. Do you want a weird bulge or do you want a little texture stretching? You will want to weight that area partially to the clavicle but mostly to the spine. Right now you are rotating the clavicle too much when you're raising the arm.You're example has…
Thank you for the reply. What you said is true, most of the time we have to balance between different issues. But still I will try to get the best result as I can. If I find some solutions before others told me here, I will post them out. As the clavicle rotation, what I learned it can raise above 30 degrees…
1) It can totally go wherever you need it, animators annihilate anatomy every day and it works great. Just don't treat it like it is the arm joint and don't ignore it. It has a limited range of motion. Personally on my rigs and in my animations I don't rotate it as much as you did, most animators I know don't go that far…