View the full tutorial here: https://youtu.be/1lZN-xMrC-g
For my mini movie project, I'm animating a poem that's all about wildflowers. That being said, I need to know how to do more than just making the flowers blow in the wind or something. I want them to sprout and bloom! So here's a summary of how to do this:
THE FLOWER & STEM
First, create your flower in illustrator--make sure to use LAYERS. I'm talking one petal per layer. Then, bring that into AfterEffects. You could draw this in AfterEffects to begin with if you want to, but I'm personally more comfortable illustrating in Adobe Illustrator.
Now that you've imported all your layers into your composition, find your flower stem layer. Add "trim paths" to this layer and alter the "end" keyframes however you like.
Next, select the whole flower head (center and all petals) and pre-compose that. Go to that pre-comp now.
There's a button in the bottom toolbar of the workspace that looks sort of like a Mac's screenshot icon. It's an unfilled rectangle containing a smaller filled rectangle. This is called the "region of interest." Click on it. Draw a rectangle/square around the head of the flower. Now go up to the top menu and... composition > crop comp to region of interest.
Go back to the main composition now. Your pre-comped flower head likely will have moved positions on the screen. First thing's first--make sure the anchor point is placed in the middle of the center circle of the flower head. The anchor point should also align with the flower stem. To double check this, you can lower the opacity a bit for the time being.
Now, add a position transformation to the flower head from the bottom of the stem to the top of the stem (at the same rate of change as the growing stem line).
Select all keyframes now (the two positions on the flower head and the two end points of the animated line) and hit F9 (the easy ease shortcut).
Go to the graph editor and navigate to the speed graph. Select the far right point on this graph and pull it toward the left. The graph will no longer be smooth, but that's what we want.
Next, select the flower head pre-comp and alter the rotation. Imagine the flower faces directly vertically up toward the sky when it's closer to the dirt, and as it grows up, it faces more of a horizontal. Apply easy ease to these rotation keyframes as well, and edit the speed graph in the same method as above.
Now, go into the flower head pre-comp. Move all anchor points of petals into the center of the flower instead of the center of the petal. In other words, the anchor of the petal should actually be at the petal's edge.
Now take each petal and alter the scale throughout the piece. It should sort of shoot out of the center of the flower. The scale should begin at 0 and end at 100. If you want to give it a little pop, extend past 100 before ending at 100. (Ex. 0 -> 106 -> 100) Easy ease again, of course.
Go to the graph editor again, this time going to the value graph. Alter the curve of the graph until it looks how you want it to.
Now, type "cc bend it" into the effects search bar. Drag "cc bend it" to that petal layer to apply the effect. Move the new anchor the a point where the whole petal is filled. Now add bend keyframes. Alter to your liking. It doesn't take much. It could be (0 , -4, 0). It'll just give it a little wiggle for some added interest. Easy ease again, and you can edit the curves in the graph editor.
To make this effect more floppy and cute, grab your keyframes, and use the opt>right arrow key shortcut to bump them over so it doesn't happen at the same time as everything else.
Now, select every keyframe you have just created on that petal. Copy it. Paste it onto all other petals. It's going to look all screwed up. Go through each individual petal, select the bend it effect, and reposition those effect anchor points.
You can drag the layers over kind of sporadically (so they start in different places), which will make your bloom more dynamic. (See 11:45 in tutorial) You'll want to drag the whole group to the right as well to make sure the flower hasn't bloomed already when it's like a cm out of the ground.
Alter the scale of the center circle as well so it grows to full size as the stem grows.
There's a transformation for color as well (you can search in the search bar for it if you can't find it), so you can start that center circle at a different color and transition as it grows so it looks more like a bud.
THE LEAF
Move the anchor point to the base of the leaf rather than the center. It should align with the stem.
Add scale and rotation keyframes so that the leaf grows once the stem hits that point. You can make the leaf wave and bounce a bit like you did with the flower petals. Once again, easy ease everything and edit to your liking in the speed and value graphs.
Adding bend to the leaf can be cool too because you can practically bend the leaf in half and let it pop up as it grows. You can copy and paste these effects to continue the waving of the leaf.
THE WHOLE THING
You're done now--unless you wanna get extra cute. You can precompose the whole flower now and add cc bend it to the whole flower so the whole thing sways.