SpringBox

SpringBox v2.1

Physics-based spring animations for Adobe After Effects.
SpringBox is a free After Effects script that adds elastic overshoot, gravity bounce, and squash & stretch animations to any layer — in one click. No manual expression writing, no keyframe fiddling.

Installation
1. Copy the file
Place SpringBox.jsx into your ScriptUI Panels folder:
Mac: ~/Library/Application Support/Adobe/After Effects/<version>/Scripts/ScriptUI Panels/
Windows: %APPDATA%\Adobe\After Effects\<version>\Scripts\ScriptUI Panels\
2. Allow script access
In After Effects go to Edit → Preferences → Scripting & Expressions and enable “Allow Scripts to Write Files and Access Network”.
3. Open the panel
Go to Window → SpringBox.jsx. Dock it anywhere in your workspace.

The Interface
The panel has two dropdowns at the top and a button row below.
Type dropdown — Choose your animation mode: Elastic, Bounce, or Squash & Stretch.
Preset dropdown — Choose the intensity: Soft, Medium, Heavy, or Custom. Both dropdowns resize with the panel.
Button row
▶ Apply — Applies the animation to your selected layer.
⚙ — Opens the Custom Preset settings where you can define your own values.
✕ — Removes all SpringBox expressions and sliders from the selected layer.
? — Opens the About dialog with version info and website link.
Controller checkbox — At the bottom left. When checked, Apply creates a shared controller null instead of writing sliders to each layer individually.

Animation Modes
Elastic — Classic spring overshoot. Great for UI popups, position snaps, and scale reveals. Adds sliders: SB_Amplitude, SB_Frequency, SB_Decay.
Bounce — Gravity-driven bounce that respects layer velocity. Works on Position, Scale, and Rotation. Adds sliders: SB_Elasticity, SB_Gravity, SB_nMax.
Squash & Stretch — Velocity-based squash applied automatically to Scale. No property selection needed. Adds sliders: SBS_Amplitude, SBS_Frequency, SBS_Decay, SBS_Delay.

How to Use
1. Pick a mode — Select Elastic, Bounce, or Squash & Stretch from the left dropdown.
2. Pick a preset — Select Soft, Medium, Heavy, or Custom from the right dropdown to control the intensity.
3. Select your layer — Click the layer in the timeline. Make sure it has keyframes so the spring has something to react to.
4. Click ▶ Apply — SpringBox writes the expression and adds Slider Controls to the layer’s Effect Controls for live tweaking.
5. Tweak the sliders — Open Effect Controls and adjust the SB_ values. Every change is instant.
6. Remove — Select the layer and click ✕ to strip all SpringBox expressions and sliders cleanly.

Presets
Soft — Subtle, gentle spring. Good for secondary motion.
Medium — Balanced feel. A solid starting point for most animations.
Heavy — Exaggerated, punchy spring. Great for character and UI emphasis.
Custom — Uses values you define yourself. Click ⚙ to set them.

Custom Preset
Click the ⚙ button to open the Custom Preset settings. You’ll see input fields for all three modes — Elastic, Bounce, and Squash & Stretch. Enter your values and click Save. SpringBox remembers your settings between sessions using After Effects’ built-in preferences — no external file needed.

Controller Mode
Check the Controller checkbox before clicking Apply to create a shared null object that controls all layers at once.
Without Controller — each layer has its own sliders. Good for per-layer customisation.
With Controller — one null drives all selected layers. Change one slider, every layer updates. Great for large scenes.
One null is created per mode: SB_Controller_Elastic, SB_Controller_Bounce, SB_Controller_Squash.
⚠️ Removing expressions does not delete the controller null — it stays in your comp in case other layers still reference it.

Slider Reference
Elastic
SB_Amplitude — Overshoot intensity. Higher = more bounce.
SB_Frequency — Oscillation speed.
SB_Decay — How fast the spring settles. Higher = faster.
Bounce
SB_Elasticity — Energy kept per bounce (0–100).
SB_Gravity — Gravitational pull strength.
SB_nMax — Maximum number of bounces.
Squash & Stretch
SBS_Amplitude — Stretch intensity.
SBS_Frequency — Oscillation frequency.
SBS_Decay — Damping speed.
SBS_Delay — Follow delay in seconds.

Free for personal and commercial use. Made with ♥ by Ruhul Amin.