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# 3.2 Arms Control

In this lesson you will learn how to create controls for the arms of the character.

## 5.Conclusion1 lesson, 00:51

### 3.2 Arms Control

Hi everyone, and welcome back to the Rig a Rubberhose Character Course. In this lesson, we'll be going through how to create the control for the arm. So as you can see from the previous setup, the only way that we can really control the arm is if we can select Spline. And if we can somehow get hold of the points here, we can move the points like so. Or if we can select the elbow like so. And doing this isn't really efficient, so we'll need to create a control. So the only way we can do this is if we right-click on Spline. Go to Character Tags, and click on IK. And then under the Tag tab, we want to turn on point IK. And what this will do is it'll look for the points of the spline that we have created, and work out how the arm is going to move. And to help with this, we'll need to define a start and end point for this. Now, the way that this is done is it's done by the order that the points are created. So if we look at our spline here, we've got point zero, which is the first one here. Point 1, which is the elbow. And point 2, which is the hand. So let's define the end point, which is point 2, so if we press number 2 here. And now, straight away you can see that once we've done that, there is a green line which connects point 2 and point zero. And it basically shows the relationship between the start and the end points of our arm. Now we have set the goal. Now the thing that we have to do is set the goal, which is basically a thing that will guide where our hand's going to move to. So let's click on Add Goal, which is here. And this will basically create a Null, which is here, which will act as the goal for our arm. So we can rename this R_Arm.Goal. And now, you can see if we start to move the goal, the arm will start to move as well. So let’s unhide our arm, go back to our Perspective View. And making sure that right arm goal is selected, we can use the Move tool to sort of move our arm like so. And you can see now that everything is connected from our hand, our elbow, and our shoulder. So this is how the rubber hose arm will move. Kind of like how you would control a puppet. Now, the problems start arising if we try and make our arm go up here. So if you wanted our character to wave, let's say, if you wanted him to say hello, it kinda looks awkward because the elbow is pointing towards his head. So it doesn't quite work that way. So the only way that we can sort of fix this is to control the elbow. And to control the elbow, we'll need to create a pole vector. So let's just press Ctrl+Z so that the arm goes back to it's original state. And to create a pole vector, we'll need to go Spline Wrap. No, let's go to the right arm spline, click on IK here. And if we scroll down, making sure that we're under the Tag tab here, scroll down past the Add Goal, where Pole Vector is, and we'll want to click on Add Pole. And again, this will create a right arm spline pole here. And you can see that our arm sort of looks really weird here. And the reason for that is, if we go to our Top View, our Spline Pole is inside the center of our character. So if we move this here, I move it around, you can see, if we go to all of our views, how this sort of controls the elbow of our character. So instead of it being inside our character here, if we move it outside sort of around this sort of area here, our arm now looks a little bit more natural because this controls the elbow and we can also twist it here. But we want it just behind the elbow, just behind the arm here. So now, you can see that we can control the elbow with this pole. And now, if we grab our arm goal like so, and if we try and make it wave like we did previously, there we go. Our elbow is pointing in the correct direction, and he can wave to all of his friends like so. Excellent. So that is how you create a control for the hand and the elbow. We can actually move this a little bit further out here like so. Excellent. So now that we have the controls for the arm and the elbow, the next thing we'll want to do is create a control for the shoulder so that we can control and rotate the entire arm. To do this, we need to group the arm. So let's group the arm spline by pressing Alt+G on our keyboard to create this Null. And now, let's rename this null R_armcontrol. And now, let's click on the Enable Snap button here, and click on the Enable Axis button here. And we are going to snap the anchor point of this Null to the arm spline. So to make things easier, let's go to display and lines. We are just gonna zoom in here, and let's go over to where our shoulder is, and we want to snap this. To our spline. Vertex Snap. So that's R_arm spline Vertex Snap. So that's the one we want, so we want to snap it to that. Excellent. So now, what we're going to do from here is if we expand this, we're going to drag the ArmGoal on top of the right arm spline here. And now, if we click on the arm control, let's click on these two buttons so that we can deactivate those buttons. And if we, making sure that R_arm control is selected, and using the Rotate tool, let's go to shading again. You can see now that we rotate our entire arm. Which is very useful. Excellent. So now that we have the arm moving and behaving in the way that we want it to, in the next lesson we'll be going through the process on how to rig the leg. See you all there.

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