Introduction
Slicing a clip into multiple parts is a popular technique for split-screen animations, stylized transitions, and dynamic motion graphics. In this tutorial, you’ll learn how to divide a single video into multiple vertical slices using solids, track mattes, and smooth animation in After Effects.
Step 1: Import Your Footage
Go to File → Import → File and import your video into the Project panel.
Step 2: Create a New Composition
Create a new composition that matches your video settings (for example, 4096 × 2160).
Step 3: Create Solid Masks for Slicing
Go to Layer → New → Solid and create three (or more) solids. Each solid should be the same size and together fully cover the composition. Example for a 4096 × 2160 video sliced into 3 vertical sections:
Solid width: 1365 px
Solid height: 2160 px
Position the solids side by side so they completely cover the composition frame.
