This chapter is from the book
This chapter is from the book
This chapter is from the book
Creating nulls from paths
When you parent one layer to another, the child layer adopts the parent layer’s attributes. But it’s a bit trickier when you want to create a relationship between a single point on a shape and another layer. The Create Nulls From Paths panel makes it easier to do just that. A null object is an invisible layer that has all the same properties as other layers so that it can serve as a parent to any layer. The Create Nulls From Paths panel creates null objects based on specific points, which you can then parent to other layers without having to write complex expressions.
You’ll draw a stem and leaves that emerge from the flowerpot to meet the falling star. You can simply parent the layers to each other to move the stem and leaves in unison, but to attach the stem to the flower, you’ll need to create a null.
Drawing shapes with the Pen tool
First you’ll draw the stem. It will have a slightly thicker stroke than the flower, but no fill, and it will rise to meet the flower. The leaves will have a fill but no stroke.
Go to 4:20, when the flower is in its final position.
Select the Pen tool in the Tools panel.
Click the word Fill to open the Fill Options dialog box, and then select the None option, and click OK.
Click the Stroke Color box in the Tools panel, change the stroke color to green (we used R=44, G=73, B=62), and then click OK. Change the Stroke Width to 3 px.
Click just below the rim of the flowerpot to create an initial vertex, and then click at the center of the flower. Before releasing the mouse, drag the Bezier handle to create a subtle curve in the stem.
Select the Shape 1 layer, press Enter or Return, change its name to Stem, and press Enter or Return again.
With the Stem layer selected, press P to reveal its Position property. Then click the stopwatch icon (
) to create an initial keyframe at its final position.Go to 3:00, and press Alt+[ (Windows) or Option+[ (macOS) to set the In point of the layer to the current time.
Select the Selection tool in the Tools panel, and drag the stem down so that it is completely below the top of the flowerpot. Press Shift as you drag to move it straight down.
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The stem will begin to emerge from the pot at 3:00. Now you’ll draw the leaves.
Go to 4:20, where the flower is in its final position.
Press F2 or click an empty area of the Timeline panel to deselect all layers. Then select the Pen tool in the Tools panel, click the Fill Color box, select a color that is similar to the green stroke color (we used R=45, G=74, B=63), and click OK. Click the word Stroke, select None in the Stroke Options dialog box, and click OK.
Click an initial vertex for the leaf near the base of the stem, and then click one for the other end of the leaf. Before you release the mouse, drag the Bezier handle to create a curved leaf.
Press F2 to deselect the layer, and then repeat step 12 to draw another leaf for the other side of the stem.
Select Shape Layer 1, press Return or Enter, rename it Leaf 1, and then press Return or Enter. Then rename Shape Layer 2 Leaf 2.
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The layers aren’t needed until the stem begins to emerge at 3:00, so you’ll set their In point to match the stem’s.
Go to 3:00. Select the Leaf 1 layer and Shift-select the Leaf 2 layer. Then press Alt+[ (Windows) or Option+[ (macOS) to set the In point for both of the layers.
Parenting layers
You’ll parent the leaves to the stem, so they’ll emerge with it.
Move the Stem, Leaf 1, and Leaf 2 layers beneath the Base of Flowerpot layer in the Timeline panel so that the stem and leaves will be behind the flowerpot as they rise.
Hide all layer properties, and deselect all layers.
Drag the pick whip (
) from the Leaf 1 layer to the Stem layer, and then drag the pick whip from the Leaf 2 layer to the Stem layer.
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The Leaf 1 and Leaf 2 layers will move in relationship to the Stem layer.
Using nulls to connect points
There are three options in the Create Nulls From Paths panel: Points Follow Nulls creates nulls that control the position of the path points; Nulls Follow Points creates nulls that are controlled by the positions of the path points; and Trace Path creates a single null with its position linked to the coordinates of the path.
You’ll create a null for the point at the top of the stem, and then you’ll parent that null to the flower so the two remain connected even as the flower moves.
Go to 4:20 so you can see the stem and leaves well.
Choose Window > Create Nulls From Paths.jsx.
Expand the Stem layer in the Timeline panel, and then expand Contents, Shape 1, Path 1.
Select Path.
You must select a path in the Timeline panel in order to create a null using the options in the Create Nulls From Paths panel.
Click Points Follow Nulls in the Create Nulls From Paths panel.
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After Effects creates two nulls, corresponding to the two points on the stem path. The null objects appear in gold in the Composition panel, and as layers named Stem: Path 1 [1.1.0} and Stem: Path 1 [1.1.1] in the Timeline panel. You only need the null for the top point.
Select the null that corresponds to the bottom point of the stem, and delete it.
In the Timeline panel, drag the pick whip (
) from the Stem: Path 1 [1.1.1] layer to the Falling Star layer.Move the current-time indicator across the time ruler to see how the stem connects to the flower.
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You’ll animate the flower subtly, and the stem will move with it.
Go to 4:28, and use the Selection tool to move the flower a bit to the right as if it had been moved by the wind.
Select the Falling Star layer, and press R to reveal its Rotation property. Then go to 4:20, and click the stopwatch icon to create an initial keyframe at its original rotation. Go to 4:28, and change the rotation to 30°.
Choose File > Save to save your work.
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