Connecting the follow joints

00:03

So next, we need the follow joints to move with the arm too,

00:07

but we need to be careful. So we don't add that twist back in

00:12

to do this. We're going to use an I

00:14

handle.

00:16

So go to skeleton, I care handle and open the options.

00:20

We need a rotate plane solver here. So we can control that twisting movement.

00:25

Create one from the follow joint to the follow tip joint.

00:30

Let's rename this to upper arm. Follow I care handle.

00:34

We are going to parent this to the elbow joint

00:37

but first match the transforms. So it's the same position

00:42

and now parent it to the main elbow joint,

00:45

the skinned joint

00:48

there, we can see it in position.

00:50

What this will do is make the IK follow the

00:53

arm which will then move the follow joints for us.

00:57

So if I rotate the shoulder,

00:59

the joints and the locator follow it,

01:03

the same happens if I raise and lower the arm.

01:05

So the locator is staying behind the arm,

01:09

the problem is the twist has come back again.

01:12

We can fix it easily though with the IK handle,

01:15

let's find it

01:17

there. It is

01:19

all you need to do is set the po vector attributes to zero.

01:24

Now, we can move the arm and the locator follow us.

01:28

And if we twist it, the shoulder maintains its orientation.