Brandon Griffin

Advice Skinning Shoulders on Rig

Fellow Cookies!

I have been practicing rigging a character model of my own creation, and I am struggling to comprehend the relationships of the various bones around the shoulder.

Here is basically the target pose. As you can see, there is some work to do, particularly in the shoulders and forearms. I'd like to focus on the shoulders.

Here are various views of the painted weights and the wireframe.


Any advice on improving either the mesh or the weight paint is appreciated!


Thanks!

  • cgrifter  I am definitely not an expert on rigging, so take this with a grain of salt, but two things after looking at the pictures.  Are the upper arm bones parented to the clavicle.  It looks like they might be in your images and I don't think that is common practice.  Clearing the parent might get you cleaner shoulder deformations.  Also I think the bone joints normally rotate toward the z axis, so you will want to adjust the roll such that the z axis points toward the joint creases (like the elbow pit, it looks like the z axis comes out the side of your elbow).  Also check to see if "Preserve volume" is checked in the armature deform modifier.  I think it is off by default and that may also help.  Again, not real solid on my rigging skills so if this is useless, sorry for wasting your time, but I hope it's helpful.

  • Hey Brandon, this character looks so good man! I've been trying to figure out some rigging myself lately. I came across this tutorial/article. Its a long read but it has some goodtheory about the torso and shoulders. I hope it helps.

    http://ainetutorials.blogspot.com/2015/11/tutorial-principles-of-blender-rigging_21.html


  • pprocyonlotor Thank you for taking the time to consider my request!

    The upper arm bones are indeed parented to the clavicle, which is in following with a couple different tutorials. I will try clearing the parent to see how it goes, because I can see how it might be beneficial.

    I have learned that the main rotation of a bone is around the x-axis. Of course, the shoulder is a rather complex joint, but I interpret this to mean that the up/down action of the arm should be around the x, making the forward to back action around the z.  That said, given that this guy is a knuckle walker, it might make sense to adapt the roll to better suit the action. Also, the clavicles might want for better orientation, 

    I do have "Preserve volume" checked. :)

  • phoenix4690 Thanks Phil! I will have a look into this article and see if I can glean some help out of it.

    Also, if you feel like practicing animation on this guy when his rig is better, I'll shoot him your way. :)


  • cgrifter Please do, I would love to swing him through some trees and poke at ant hills with sticks. :)

  • maybe check out this youtube channel...

    from a fellow blender cookie...

    lots of good stuff

    https://www.youtube.com/user/Dantreige/videos