Start your free trial now, and begin learning software, business and creative skills—anytime, anywhere—with video instruction from recognized industry experts.

Start Your Free Trial Now

Coordinating simple properties


From:

After Effects Apprentice 09: Expressions

with Chris Meyer and Trish Meyer

Video: Coordinating simple properties

Let's build upon what you learned in the last movie to use expressions to tie together similar properties. In this case, I'm going to open up the comp 02-Simple Math*starter, select both layers, Command+A or Ctrl+A, press U to reveal their animating properties. And once again, the first letter has been keyframed the second layer has been tied the first layer using expressions. I'll do a quick RAM preview here. Nothing strange there. Okay, let's say we want a jazz this animation up, add a drop shadow to these layers.
please wait ...
Watch the Online Video Course After Effects Apprentice 09: Expressions
1h 37m Intermediate Jul 27, 2011 Updated Nov 29, 2012

Viewers: in countries Watching now:

Expressions are one of the most powerful but underused features in After Effects. They can be used to animate layer properties with code, as compared to explicitly keyframing every value in the Timeline, and have multiple parameters and layers that follow the lead of a master layer or controller effect, making it much easier to coordinate complex animations and quickly accommodate client changes. In this introduction, Chris Meyer shows how to let After Effects do most of the work by creating simple but very useful expressions that can be put to work on a wide variety of jobs.

The After Effects Apprentice videos on lynda.com were created by Trish and Chris Meyer and are designed to be used on their own and as a companion to their book After Effects Apprentice. We are honored to host these tutorials in the lynda.com Online Training Library®.

Topics include:
  • Creating and managing expressions
  • Linking together different parameters
  • Randomizing a layer's movement
  • Looping an animation
  • Controlling multiple layers from a single source
Subject:
Video
Software:
After Effects
Authors:
Chris Meyer Trish Meyer

Coordinating simple properties

Let's build upon what you learned in the last movie to use expressions to tie together similar properties. In this case, I'm going to open up the comp 02-Simple Math*starter, select both layers, Command+A or Ctrl+A, press U to reveal their animating properties. And once again, the first letter has been keyframed the second layer has been tied the first layer using expressions. I'll do a quick RAM preview here. Nothing strange there. Okay, let's say we want a jazz this animation up, add a drop shadow to these layers.

I'll select the blue pulley and apply Effect > Perspective > Drop Shadow. And to make it stand out a little bit, I'll give a little bit more Distance, maybe just a little bit Softness. That looks nice. Now if you've watched the previous lesson in our After Effect Apprentice series on nesting and pre-composing, you know that we drove home the point of the render order of layers, and by looking at the timeline panel, you can quite often figure out what that render order is. In this case, effects such as the drop shadow happen before the transforms, such as the scale and rotation. And indeed, as that blue pulley rotates, you can see the shadow, unfortunately, is rotating along with the pulley, which is not at all what we want.

Now there are a few ways of fixing that, including by using expressions. Rotation is a very simple parameter using degrees. The Drop Shadow also has a Direction property that uses degrees. What can we do with expression to tie these two together? Let's think for a second. As that pulley rotates counterclockwise, we need the shadow to rotate in the opposite direction by exactly the same amount to stay in the same relative position.

Okay, that's gives me the clue here: before you apply expressions make sure that all the properties you want to deal with are exposed. My Drop Shadow is exposed in Effect Controls panel and the blue pulley's rotation is exposed on the Timeline panel. That's good. We need the drop shadow to follow the rotation, so the drop shadow is what needs to get the expression. I'll hold down Option on Mac, Alt on Windows, click on the stopwatch for direction. It'll appear down here in the Timeline panel with expressions enabled.

You'll see that it has a red value now. Its text is highlighted, ready for action. I'll click on this pick whip and drag this pick whip down to Rotation property for the same layer, and you'll see it's picked up the transform rotation already. It wrote the code for me automatically. Now if I leave this alone, it just means it is going to be the same, but what I really need is for this to rotate in the opposite direction, times -1. Press Enter, and now as I scrub through the timeline, you'll see the shadow is appearing to remain stationary.

In reality, its direction is just rotating exactly the opposite to the rotation of the gear. Well, we are most of the way there, but now my shadow is going up the screen, not down to the right like it was before. That's easy to fix. Remember, you can also add offsets these layers. I can type in a number, like say 120 degree, or remember, you can say +value to pick up the underlying value of this property, which defaults to 135 degree. I'll press Enter.

My shadow falls down in position. I'll turn off expressions briefly to remind us that we did indeed have 135 degree underneath, and here is our lovely shadow now exactly where it's supposed to be, thanks to expressions. Expressions, by the way, are just another property of an effect or other value. For example, if I select Drop Shadow, Command+C or Ctrl+C to copy, go to the Red Pulley and Command+V or Ctrl+V to paste, not only will it paste the drop shadow, it will paste the expression attached to that drop shadow.

You'll see that it has a red value now to show that it has an expression applied, and now both of these layers indeed have properly positioned drop shadows. So that's another use of expressions, just to solve some very simple math issues of things rotating the wrong direction, rotating too fast, too slow, et cetera. I know math is usually an ugly word for artists; however, by combining expression with just a little bit of math, you can solve a lot of problems without having to add extra keyframes or come up with another design approach or whatever.

Expressions can be your friend. In the next movie, we'll take this to the next level by tying together the different hands of a watch.

Find answers to the most frequently asked questions about After Effects Apprentice 09: Expressions .


Expand all | Collapse all
please wait ...
Q: This course was updated on 11/29/2012. What changed?
A: We have added exercise files designed for After Effects CS6. We also added a movie that shows our premium subscribers how to use the exercise files.
 
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ .

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

Join now Already a member? Log in

* Estimated file size

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed After Effects Apprentice 09: Expressions.

Return to your organization's learning portal to continue training, or close this page.


OK

Upgrade to View Courses Offline

login

With our new Desktop App, Annual Premium Members can download courses for Internet-free viewing.

Upgrade Now

After upgrading, download Desktop App Here.

Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member ?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Learn more, save more. Upgrade today!

Get our Annual Premium Membership at our best savings yet.

Upgrade to our Annual Premium Membership today and get even more value from your lynda.com subscription:

“In a way, I feel like you are rooting for me. Like you are really invested in my experience, and want me to get as much out of these courses as possible this is the best place to start on your journey to learning new material.”— Nadine H.

Start your FREE 10-day trial

Begin learning software, business, and creative skills—anytime,
anywhere—with video instruction from recognized industry experts.
lynda.com provides
Unlimited access to over 4,000 courses—more than 100,000 video tutorials
Expert-led instruction
On-the-go learning. Watch from your computer, tablet, or mobile device. Switch back and forth as you choose.
Start Your FREE Trial Now
 

A trusted source for knowledge.

 

We provide training to more than 4 million people, and our members tell us that lynda.com helps them stay ahead of software updates, pick up brand-new skills, switch careers, land promotions, and explore new hobbies. What can we help you do?

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.