Animation in After Effects: Your beginner's tutorial

Tips and tricks for animating in After Effects: Trimming compositions

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Philipp Sniechota
By Philipp Sniechota Last updated on Shown in: Adobe After Effects CC 2014
Tips and tricks for animating in After Effects: Trimming compositions

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When I create my compositions, it often happens that I don't yet know what I'm going to do in them or what size they should be in the end.

In this example, I have a smiley composition in a larger composition. But unfortunately there is a lot of empty space around the smiley - which means that it is more difficult to animate the smiley itself in the larger composition.

Tips and tricks for animating in After Effects: Trimming compositions

Unfortunately, After Effects does not have the practical option of simply selecting the relevant area and cropping it automatically.

But we have another function that helps us with this: we can select the relevant area manually. This is actually there to render only a certain pixel area in render-intensive scenes, but it allows us to make a selection here.

This tool works in a similar way to the clipping tool in Photoshop and we can only select the important area.

Tips and tricks for animating in After Effects: Trimming compositions

Finally, we confirm the relevant area by going to Composition>Crop composition to relevant area.

Tips and tricks for animating in After Effects: Trimming compositions

Now we can animate our smiley in the larger composition without any problems and without an unnecessarily large border.

Tips and tricks for animating in After Effects: Trimming compositions

If the smiley would now move and I would like to find out in which area it is moving - for example by expressing the position with wiggle(5,100), I can first create a new adjustment layer with Ctrl+Alt+Y. Then I can right-click on the effect settings and go to Time>CC Time Blender.

Tips and tricks for animating in After Effects: Trimming compositions

In CC Time Blend, we then go to Composite Over or Composite Under and set the Accumulation to 100.

Using this method, we can make all the frames of the smiley visible on top of or underneath each other.

Tips and tricks for animating in After Effects: Trimming compositions

Now we can select the relevant area again and use Composition to crop the relevant area. And now we have perfectly cropped everything relevant, including the movements, and can edit it further without any problems.

Tips and tricks for animating in After Effects: Trimming compositions

Philipp Sniechota
Trainer About Philipp Sniechota Philipp Sniechota is a motion designer and works as a freelancer for various moving image agencies. He specializes in 3D design and motion design and teaches his know-how to beginners and users at national and international conferences and workshops. All courses by Philipp Sniechota