Updating clavicle rotation

00:03

Now let's look at the orientations.

00:06

First, let's display the rotational axes.

00:09

So we can see how these are being affected.

00:12

So you can clearly see as I move the control,

00:15

the rotations on the clavicle joints aren't being updated.

00:20

What we can do is use aim constraints again to

00:23

make sure the clavicle always points towards the shoulder.

00:27

But to ensure we don't get any rotational issues or the joints flipping,

00:32

we will use a locator to stabilize the constraint.

00:36

So create a new locator

00:38

and match it to the upper spine or spine three's position.

00:43

So it's up here. Now,

00:45

let's move it back behind the torso

00:47

and scale it a little. So we can see it.

00:51

I'm also going to move it up a little. So it's more in line with the clavicles, Z axis

00:58

around here should be fine.

01:01

And let's rename this to clavicle aim.

01:05

We want it to move with a torso. So parent it to the spine three joint.

01:12

OK. That follows good.

01:15

Now, select the left arm, root control

01:18

and then the left clavicle joint

01:21

and go to constrain

01:23

aim and open the options.

01:27

I'll reset this.

01:29

So we want the aim vector to be set to Y. So the Y axis points to the root control

01:35

world up type should be changed to object up. So we can use the locator's position.

01:40

And now add the locator's name

01:42

clavicle aim

01:45

the up vector also needs to match the axis which will be pointing at the locator.

01:50

So this is minus Z

01:54

let's apply that.

01:56

All right, I put the wrong a vector in,

01:58

I set it to X.

02:00

Let's undo and change this to why?

02:04

So we need a one here

02:06

and apply that again.

02:08

OK. That's better.

02:09

Why is pointing at the control? Now,

02:13

it's important to mention that you can

02:14

edit a name constraint after you've created it

02:17

just in the attribute editor.

02:20

So you don't always need to delete them and

02:21

recreate them if you added in the wrong values.

02:25

So what I want to do now is undo it

02:28

and reset the root control

02:29

because I don't want there to be too much movement when created.

02:33

So I want to double check this when it's applied in a neutral pose.

02:37

Let's apply this again.

02:39

So you see we have some small rotation values here. Now,

02:43

if we wanted, we could adjust the locators position to just try and remove these.

02:50

But this is OK for this rig.

02:52

OK. Now, as we move the root control, the clavicle joint rotates to follow it.

02:57

Perfect.

02:59

Let's add the constraints to the opposite side. Now.

03:02

So on this joint, the Y axis is pointing the opposite way.

03:05

So we need to change the aim vector to minus one instead.

03:10

And the Z axis is pointing towards the locator.

03:14

So we can remove the minus from the up vector

03:18

and apply that

03:21

that works now too.

03:23

And both are locked to the locator,

03:26

meaning we compose the spine

03:29

and the constraints are more stable with less risk of them flipping.