Adding twist joints

00:03

So next, we need to add the twist joints.

00:09

You can see one here on the unreal skeleton.

00:12

Let's copy that name for now,

00:16

duplicate the lower arm joint

00:21

and delete its Children.

00:23

So there is nothing parented to it.

00:25

We need this joint to be exactly half way between the lower arm and hand joints.

00:31

The quickest way to do this is to use another constraint.

00:34

So like the hand and the lower arm joints

00:38

and add the new lower arm underscore L one joint to the selection

00:44

you had this one last because this is the joint being constrained.

00:48

Now go to constrain point just as we did earlier.

00:52

So just like we did with the eye, we need to maintain offset disabled.

00:55

So the joint moves,

00:58

you can see that it's now moved between the other joints.

01:02

Now it's in position, we can delete the constraint

01:06

and parent that to the lower arm joint.

01:09

So it moves with the lower arm. Also, we need to remember to rename the new joint.

01:14

So let's paste the name we copied earlier. So it matches the unreal skeleton.

01:20

That's the lower arm done.

01:21

Let's move to the upper arm and we are going to

01:24

treat this area a little differently to the unreal mannequin.

01:28

So as before

01:29

duplicate the upper arm joint

01:32

and delete its Children.

01:36

Let's find the name of the twist joint.

01:40

Here it is.

01:43

Let's rename our new joint before we move on.

01:48

There we go

01:50

with this first joint. We're going to leave it here.

01:52

We need this to help with how the shoulder rotates and deforms.

01:57

If you rotate your own shoulder forwards and backwards, up and down

02:01

the shoulder moves with it.

02:03

However, if you twist your arm, the shoulder doesn't twist

02:07

instead your arm twists around the bicep area.

02:11

So we will use this joint later to help replicate this movement.

02:15

Now we need a second twist joint. This will sit in the middle of the arm.

02:20

So duplicate the first

02:22

and change the number to two,

02:25

just like with the lower arm, we will use a constraint to position it.

02:29

So select the lower arm and upper arm joints

02:32

and then the second twist joint

02:34

and create a point constraint

02:37

that's moved. So we can now delete the constraint

02:43

and parent the joints to the upper arm.

02:50

So that all moves together,

02:52

that's the extra arm joints added.

02:54

So let's now add them to the leg and it's exactly the same process.

02:59

Let's copy the name from the unreal skeleton.

03:07

So with the thigh, we are going to use the same set up as the upper arm.

03:10

So we can get the correct defamation.

03:12

Meaning the upper thigh doesn't twist as much as the lower

03:16

duplicate the thigh

03:19

and delete everything underneath it.

03:21

Now, rename it, just paste the name you copied previously.

03:25

Duplicate that twist joint

03:28

and change the number from 1 to 2

03:35

and use another point constraints to update its position.

03:44

Remember to delete the constraint node.

03:48

Oh, and I'll fix that name.

03:52

OK. That's better.

03:54

Now, parent it to the thigh joint.

04:02

The first twist joint needs parenting to it too

04:06

good.

04:09

Actually, I'll update the upper arm too,

04:12

moving the first twist joint. So it's parented to it

04:19

right next section.

04:23

So copy the name,

04:25

we need to do this lower section because this is a calf,

04:30

duplicate the calf and then delete its Children.

04:33

Oh That sounds so harsh. Delete your Children,

04:37

rename it to twist one.

04:39

Now update its position with a point constraint

04:46

and then delete the constraint

04:50

and parent the joint to the calf.

04:53

Now let's do the knee section.

04:56

So copy the knee,

04:58

delete the other joints beneath it.

05:01

That way of putting it sounds better.

05:03

Update the name. So we know it's a twist joint

05:06

point constrain it to the calf and knee joints.

05:11

Actually,

05:12

you may be wondering why I use a point constraint and not a parent constraint.

05:16

Let me quickly demonstrate the difference.

05:20

If I use a parent constraint instead,

05:22

we can tell it to use the translations and rotations,

05:26

applying that moves the joint. But it also rotates it too.

05:30

So as you can see

05:31

the joint's orientation has changed, whereas we need it to remain the same.

05:36

This is because it's trying to find an in between point from the

05:39

orientation of the first joint and the orientation of the second joint.

05:44

This is why I prefer to use a point constraint. In this instant,

05:47

the orientation is kept the same as the knee joint.

05:51

OK. Let's delete that

05:54

and parent the twist joint to the knee.

05:57

OK. All done.

05:60

So that's the main joints we need at this stage.