Configuring the arm twist joints

00:03

When we built the skeleton, we added a series of twist joints

00:08

at the moment, these don't really do much.

00:10

So let's now look at getting these working,

00:13

let's switch to FK. So we have more direct control over the shoulder

00:18

and also get rid of the textures

00:21

and turn on wireframe.

00:23

If I rotate the upper arm,

00:25

you see that the shoulder follows the joint as you would expect.

00:29

The problem is that this isn't a natural defamation.

00:33

If you rotate your own arm,

00:34

you will see that the shoulder area doesn't twist like this.

00:38

Instead it twists around the bicep area.

00:42

So we need to mimic this in our rig.

00:45

This is where the twist joints come into play.

00:48

Let me select the upper arm twist joint

00:51

back when we were skinning the model,

00:53

we made sure the twist joint influenced the shoulder, not the upper arm joint.

00:58

This is so we can control this area more like this,

01:02

we can rotate the twist joint back to keep the shoulder steady.

01:07

What we can also do is use a second twist

01:09

joint here to make the blend down the arm more gradual