Modifying shape nodes for joint control

00:04

As well as moving shape nodes under other curves.

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You can also do the same with other nodes.

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Let's create another circle

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and make it bigger

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and freezer transforms

00:22

and also delete the history.

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Let's say we are going to use this as a control for the shoulder joint.

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First, we need to move it into position.

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So let's use the match transformations tool to do that.

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This will move the circle to the joint, matching its position and orientation.

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There we go.

00:46

OK.

00:47

So what we would traditionally do is use a parent

00:50

constraint which will constrain the joint to the control.

00:55

So now the circle controls the joint perfect.

00:60

The problem is that constraints can be

01:01

unpredictable depending on how they are used.

01:04

And ideally you want the rig to use as few nodes as possible.

01:09

Let's undo that.

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So what we can do is move the circle's shape node again.

01:15

But this time move it to the joint's transform node,

01:19

show the shapes in the outliner.

01:24

And let's bring back the script editor.

01:27

All we are going to do this time is select the shape node

01:30

and then the upper arm joint

01:33

and run the code.

01:37

So now, we can select the curve and it will select the joint.

01:40

It's basically selecting the joint for

01:43

us

01:43

much like with a selection handle,

01:46

we can delete the transform node now

01:51

and here is a shape node.

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If we disable the shapes, now

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it vanishes.

01:58

And you can see that the joint icon has now changed to a curve icon.

02:03

The beauty of this setup is that we can

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hide the joints and the control is still visible.

02:09

Unfortunately, it does also hide when the joint is manually hidden.

02:14

But you can get around this

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if you want the controls visible and the joints hidden

02:19

simply set the joints draw style to none.

02:24

This is a nice way to set up control arms or legs, for example,

02:28

where you have another layer of joints controlling the base skeleton.

02:32

What I wouldn't recommend is using these to control the base skeleton directly

02:37

as it can cause issues when exporting to unreal.