Layer React – Make Your Layers React with One Click in After Effects

A smart tool that makes your layers react to a Null or a Mask

No need to write or remember any expressions.

Simply select the effect you want and click Apply.

🚀 Instantly create smooth, professional animations — perfect for motion designers, editors, and content creators.

⭐ Ideal for explainer videos, ads, YouTube, social media, promos, and more.

Combine multiple reactions and build complex animations in seconds — flexible, fast, and fun.

Example scroll animation – Null react: Scale + Opacity

Example roulette animation – Null react: Vertical Position + Scale

Example look at object animation – Null react: LookAt

Example 3D scroll animation – Null react: Vertical Position

Example pattern animation – Mask react: Scale + Color

✨ HOW TO USE – NULL REACT

1. Select the layers you want to animate.
2. Choose the properties you want to control with a Null (Position, Scale, Opacity, Color...).
3. Click Apply — and you're done!
4. Now you only need to animate the Null using keyframes or expressions.

✅ The selected layers will react dynamically based on their distance to the Null.

✅ Note: Layers are automatically converted to 3D to ensure full compatibility with distance-based animations.

✨ HOW TO USE – MASK REACT

1. Create or select a layer to use as a mask, such as:
   • White Solid with a Mask
   • Shape Layer with Fill
   • Solid with Gradient Ramp
   • Fractal Noise or any layer with luminance contrast
2. Use the dropdown to select the Mask Layer.
3. Select the layers you want to animate.
4. Choose the properties to react (Opacity, Scale, or Color).
5. Click Apply — and it's done!
6. Animate the mask layer to control how the other layers react.

✅ The effect is driven by the brightness (white = full reaction, black = none).
✅ Use the “Transition (%)” slider to control how much the reaction blends from original to full effect.

💻 HOW TO INSTALL THE SCRIPT?

It’s easy! Just copy the two files — the script and the folder with icons — into this folder:

👉 C:/Program Files/Adobe/After Effects (your version)/Support Files/Scripts/ScriptUI Panels

Then open After Effects and go to:
Window → Layer React to launch the panel.

💡 Make sure “Allow Scripts to Write Files and Access Network” is enabled in After Effects Preferences → Scripting & Expressions.

✉️ CONTACT

For any questions, suggestion, or problem, email me to: xantips.contacto@gmail.com

📅 VERSION HISTORY

• Layer React 1.0 – May 2025
  • Product release.

FEATURES:

🔹 NULL REACT – VERTICAL

Slide your layers up or down based on their distance to the null.
Ideal for building vertical menus, reveals, or animated lists.

Sliders:

• Range (px) – Controls how far the null’s influence reaches. Layers outside this range won’t react.
• Position Y (px) – Sets how far the layer moves vertically when it’s close to the null.

💡 Tip: Combine with Opacity or Scale for smoother and more natural transitions.

🔹 NULL REACT – HORIZONTAL

Slide your layers left or right based on their distance to the null.
Great for carousels, sliding panels, or interactive layouts.

Sliders:

• Range (px) – Controls how far the null’s influence reaches. Layers outside this range won’t react.
• Position X (px) – Sets how far the layer moves horizontally when it’s close to the null.

💡 Tip: Use it with a centered null to create symmetrical sliding effects.

🔹 NULL REACT – FORCE

Push layers away from the null in all directions.
Perfect for creating impact effects, explosions, or responsive movement.

Sliders:

• Range (px) – Controls how far the null’s influence reaches. Layers outside this range won’t react.
• Radial Offset (px) – Sets how far each layer is pushed when close to the null.

💡 Tip: Works great when you place the null at the center of your composition.

🔹 NULL REACT – FOLLOW

Make your layers smoothly follow the null’s position.
Perfect for trailing effects, soft motion, or responsive layouts.

Sliders:

• Range (px) – Controls how far the null’s influence reaches. Layers outside this range won’t react.
• Follow (%) – Controls how closely the layer follows the null (0% = don't move, 100% = null position).

💡 Tip: Use lower Follow values for more fluid and delayed motion.

💡 Tip: Use it to animate eyes.

💡 Tip: Use it to reveal 3D layers.

🔹 NULL REACT – LOOKAT

Make your layers rotate to always face the null.
Great for creating dynamic eye-like movements, arrows, or character reactions.

Sliders:

(This reaction doesn’t require any sliders — it uses position data only.)

💡 Tip: Combine LookAt with Opacity or Scale to create more expressive, responsive elements.

🔹 NULL REACT – OPACITY

Make your layers fade in as they get closer to the null.

Sliders:

• Range (px) – Controls how far the null’s influence reaches. Layers outside this range won’t react.
• Opacity Max (%) – Sets the highest opacity when a layer is close to the null. Layers fade out as they move away.

💡 Tip: Set your layers to low opacity to see the fading effect.

🔹 NULL REACT – SCALE

Make your layers grow or shrink based on their distance to the null.
Useful for creating focus effects, depth, or dynamic emphasis.

Sliders:

• Range (px) – Controls how far the null’s influence reaches. Layers outside this range won’t react.
• Scale Max (%) – Sets the maximum scale when a layer is close to the null. Layers return to their original size as they move away.

💡 Tip: Try changing the default scale of your layers to create different animation styles and reactions.

🔹 NULL REACT – COLOR

Make your layers shift between two colors depending on their distance to the null.
Great for creating visual feedback, highlights, or dynamic color effects.

Sliders:

• Range (px) – Controls how far the null’s influence reaches. Layers outside this range won’t react.
• Near Color – The color applied when the layer is close to the null.
• Far Color – The color applied when the layer is far from the null. Layers blend between both based on distance.

💡 Tip: Combine this with Opacity or Scale for more expressive animations.

🧩 MASK REACTIONS

Use a white solid, white shape, gradient, or any visible layer to control how other layers react.
Reactions are based on the brightness (light or dark) of the mask layer at each layer’s position.

🔸 MASK REACT – OPACITY

Make layers fade in or out based on the mask brightness.

Sliders:

• Transition (%) – Controls the blend between original and affected opacity.
• Inside Opacity (%) – Opacity when the layer is over a white (bright) area.
• Outside Opacity (%) – Opacity when the layer is over a dark area.

💡 Tip: Use a white solid or animated gradient to create dynamic reveal effects.

🔸 MASK REACT – SCALE

Increase or decrease layers depending on the mask’s brightness.

Sliders:

• Transition (%) – Controls how much the original scale blends with the mask-driven scale.
• Inside Scale (%) – Scale value over bright areas.
• Outside Scale (%) – Scale value over dark areas.

💡 Tip: Animate a white gradient or fractal noise to simulate proximity or energy effects.

🔸 MASK REACT – COLOR

Blend two colors depending on the brightness of the mask.

Sliders:

• Transition (%) – Blends between original color and the reaction color.
• Inside Color – Color applied over bright areas.
• Outside Color – Color applied over dark areas.

💡 Tip: Combine with Scale or Opacity for more expressive reactions. You can use line with Trim Path to create a path reaction.