What joints do you have overlapping in the head?
For the elbows and knees, yes I do skip some joints. The only reason I do is because mirroring weights can get confused when joints are in the exact same position, especially in ngSkinTools, which doesn’t support mGear’s naming convention very well. ngSkinTools expects the left and right prefix to be at the beginning of the name. mGear uses foo_L0_jnt in the middle of the name. But Maya can get a bit confused sometimes too, depending on your mirror settings.
Here is how I think about skipping the elbow and knees joints. Your joints might be different numbers. (Sorry I couldn’t think of a way to write this as a shorter post!)
First though, your screenshot is in neutral pose. Learn to skin and test your rig in poses. Then you can see what effect changing your weights has.
- Joint 5 and 6 are in the same position. So I can skip one of those. Which one should I choose?
- Joint 4 and 5 have identical orientation. So 5 is just extra. I don’t need it.
- I’ll keep joint 6, because it is the first joint that rotates with the forearm/elbow. If I skip it, when I use the cartoon bend controls, joint 7 will cause the elbow to collapse.
- (If I bend the upper arm, joint 4 moving will cause the elbow to collapse a bit too, but not as much. I learned this just from testing.)
So I skip joint 5, and use joint 4 and 6 for the elbows. Joint 4 is the arm. Joint 6 is the forearm.
So I remove joint 5 in the arms, and joint 3 in my legs, for the same reason. I don’t allow those joints in my skinCluster at all.
Ideally, if mirroring didn’t get confused, I would not skip joint 5. Because then you could cartoon bend the upper arm and the lower arm, but the elbow would still remain a good solid corner shape. Joint 5 is the end of the upper arm. Joint 6 is the beginning of the forearm.