After Effects tutorial: Automate cuts to sequence comps in After Effects

Discover a simple way to automate the process of cutting a sequence of comps together on the Timeline in After Effects, and apply 3D lights, cameras and effects to all of them.

In this second in After Effects guru Angie Taylor’s new series of tutorials, you’ll sequence a series of comps using markers and clever scripts – and discover a quick way to apply 3D lights, cameras and effects.

This tutorial is part of Angie’s series looking at intermediate to advanced After Effects techniques. They’re based around a music-led advertising project inspired by an old trick her Grandad used to do with a five-pound note. He would fold the paper in such a way that when titled it would make the Queen’s face happy or sad. You can see how the trick appears here.

For these tutorials, you’re using this idea in After Effects to create an ad for a hair product. The idea is to create a Sad Hair/Happy Hair scenario where magical – and unfortunately fictitious – hair product Happy Hair cheers up your drab barnet.

In the first part, we created the concertina effect on our 3D layers using a combination of parenting and expressions.

Check back next week for the third in this series of After Effects tutorials, creating and compositing a brand new 3D object using the free Cinema 4D Lite application that is bundled with After Effects CC.

This project is based around the audio track Pages, by up-and-coming electronic act Lifecycle (which features the bass skills of Digital Arts’ own Letitia Austin).

Software needed

Adobe After Effects CC

Time taken

2 hours

Project Files

Please visit the desktop site to download the project files.


In this tutorial’s project files, I’ve provided a 30-day trial of a script that will automate the sequencing and trimming of layers. This was specially written for this tutorial by a friend of mine, Lloyd Alvarez, who runs a website called AE Scripts.

Please copy the file named Automate to Sequence.jsxbin from the Project Files > Scripts folder and paste it into the Applications/After Effects CC / Scripts / ScriptUI Panels folder (Mac) or Program Files\Adobe\Adobe After Effects \Support Files (Windows).


You also need to ensure that your After Effects preferences are set up correctly. Go to After Effects > Preferences > General and check the box next to Allow Scripts to Write Files and Access Network. You will need to restart After Effects after making this change.

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First we’ll add markers in time with the music beats whilst listening to the audio to create a dynamic, jump-cut look for our animation.

Open 01_Start.aep and then the ’01_Start’ comp. Select the Audio Edit layer. Hit the . key on the keyboard’s numeric keypad to play audio (or Ctrl + . on the main keyboard – Mac only) and then hit * on the numeric keypad (or Ctrl + 8 on the Mac) to add markers at the beats while listening to the audio.

Use the screenshot as reference. Once you’re done, we’ll use the markers to synchronise a sequence of nested compositions based on the final output of my previous tutorial.


Drag the Part One comps folder to the Timeline. This will place all of its contents into the timeline.

We want to stagger the layers so that each one begins at a marker. This is where Lloyd’s script comes in very handy! Go to Window > Automate to Sequence.jsxbin. A panel will open which you can dock anywhere in the interface.


Select all of the layers except the Audio Edit layer. In the Automate to Sequence panel, choose the Audio Edit layer from the Marker Layer drop down (if this doesn’t appear, hit the Refresh button).

Click on the Sequence Layers button to quickly arrange and trim the layers based upon the markers.

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Now we need a camera and some lights for each, which were created in my previous tutorial.

Double-click the ’01’ layer number 2 to open it, then RAM preview the animation. Notice how the camera and lights accentuate the 3D arrangement of the layers and make her change from sad to happy.

Instead of adding cameras and lights to each individual nested comp in this way, I’ll show you a trick that uses only one camera and two lights to affect all the nested comps.


Select the camera and both lights, then hit Cmd/Ctrl + X to cut them from this comp. Notice that the comp’s appearance dramatically changes when we lose the camera angle and lighting.

Hit the Tab key to open the Mini-Flowchart in the Timeline. Use this to to jump back to the 01_Start comp and then paste in the Camera and Lights. If necessary, trim the camera’s and lights’ duration to that of the comp.


Select all of the numbered nested comps on the Timeline and make them in 3D layer. Notice that they now react to the lights and camera, but the appearance is not the same as before.

This is because After Effects is rendering the nested comp and then making the rendered layer 3D. It’s like flattening the rendered layer and then treating it like a flat postcard in 3D space – it looks very flat.

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We can overcome this ‘floating postcard’ issue by rendering the 3D interactions of all the layers within these nested comps here in the Main composition. This will maintain the geometry of the layers and will allow them to react to the camera and lighting in this composition.

Click and drag down the Collapse Transformations column on the Timeline and the 3D geometry effect will return – just like magic.