Simple Replicator: hundreds of 3D copies driven by a single null

After Effects has no built-in way to clone a layer into a formation. The plug-ins that do are powerful, but paid. For a particle background, an image wall or a logo that bursts apart, I mostly needed something simple that stays editable to the end.

The script builds ordinary layers, linked by expressions to a control null. Nothing else to install, and the project opens on any machine with After Effects.

Install the panel

• To try it: File → Scripts → Run Script File…, then pick Simple_Replicator.jsx.
• To dock it: copy the .jsx into After Effects’ Scripts/ScriptUI Panels folder, restart, then open it from the Window menu.
• Optional: copy Startup/Simple_Replicator_AutoOpen.jsx into the Scripts/Startup folder. Clicking a replicator’s null then reopens the panel, even right after After Effects starts.

The panel has three tabs: Create, Replicator and Settings. A menu at the top switches the interface to English, French or Spanish. The setting names on the null stay in English, so the expressions work in every language.

Your first replicator in one minute

1. In a comp, select a layer: an image, a video, a precomp, a text, a shape layer or a 3D model. Several layers work too: the script alternates between them or mixes them.
2. In the Create tab, pick a preset or a shape, and the number of copies.
3. Click Create replicator. The script adds a Replicator 1 Control null and the copies, then switches to the Settings tab.
4. Move a slider: the formation changes at once. Moving, rotating or scaling the null moves the whole formation.

A preset sets the shape, a suggested number of copies and the animation; after that, everything is yours to change. The ten videos at the top of this article show all ten presets, rendered from the sample project in the pack.

Your original layers are hidden, not deleted. A text or shape layer goes into a small cache precomp: After Effects renders it once instead of once per copy.

Adjust everything live

Every setting of the null is mirrored in the Settings tab, in five sub-tabs: Animation, Shape, Variations, Reveal and Color. Select the null or a copy, and the panel loads that replicator on its own.

• Animate: the ◆ button sets a keyframe at the current time, × removes the setting’s keyframes.
• Variations: random position, scale, rotation and opacity, copies spinning on themselves, copies facing the camera.
• Reveal: copies appear one by one, in order, reversed, at random or from the center, flying in from a depth you choose.
• Color: random between two colors, a gradient, or one single color for every copy.

Settings that do nothing with the current shape are greyed out: no arm count outside the galaxy, for example.

Along a path, or pulled by a null

Path: draw a mask or a pen path, select it with the null, then click Use selected path. The copies spread along the path. Animate Path Offset (%) to make them travel, and tick Orient Along Path so they follow the path’s direction, like the arrows in the video.

Attractor: Add an attractor creates a null linked to the replicator. Nearby copies are pulled toward it, or pushed away with a negative strength. Animate the null, and the swarm follows.

Keep a heavy project smooth

Each copy is a layer driven by expressions, recalculated every frame. With several hundred copies, that is what slows playback down. The panel has several levers.

• Light expressions: each copy only holds the code it needs, for the chosen shape and the active settings. When you change a setting from the panel, the expressions adjust on their own.
• Precompose: moves a replicator into its own composition, with its null, attractor and path. The main comp’s camera and lights still apply.
• Turn copies off / on: turns off the eye of every copy, or of the replicators in the selected precomps. They are no longer computed at all.
• Freeze: replaces the expressions with values or keyframes. Playback gets smooth; Unfreeze makes the settings editable again.

Good habits

• Do not rename the null “Replicator N Control”: the expressions find it by name. If it happens, the Diagnostics button offers a repair.
• Adjust with few copies, raise the number with Update, and freeze for rendering if playback stutters.
• The Classic 3D renderer is the fastest for many flat layers. The script offers it when you create a replicator.
• To remove everything, Delete replicator clears the copies, the null and the cache, and shows your original layers again.
• The PDF guide in the pack covers every setting, with recipes: image wall, carousel, cloned text, explosion.