User Guide & Documentation
Everything you need to know about using FiziFlo inside After Effects. From basic layer setup to advanced force controls and keyframe baking.
Introduction & The "No Preview" Workflow
FiziFlo (formerly MessFizix) brings the power of a 2D physics engine directly into Adobe After Effects. Instead of relying on a separate "live preview" window that forces you to guess what your render will look like, FiziFlo calculates and bakes keyframes concurrently directly to your timeline.
How this workflow benefits you: You see the exact physics results applied to your actual AE layers, with your real masks, layer styles, and motion blur. Don't like how a bounce looks? Just click Clear Keyframes, adjust a slider, and hit Bake again. It perfectly matches the fast, iterative workflow of professional motion design.
Installation
- Download the FiziFlo package from your purchase receipt and extract it.
- Run the included installer script — Install.bat on Windows or Install.command on Mac. This copies the extension to the correct CEP extensions folder on your system.
- Launch (or restart) After Effects.
- Navigate to Window > Extensions > FiziFlo to open and dock the panel.
Step 1: Adding Bodies
The foundation of any simulation. "Bodies" are physical representations of your After Effects layers. To start, select the layers you want to simulate in your timeline and click Build from Selection in the panel.
Body Types
- Dynamic: The default. These bodies fall with gravity, bounce, and are pushed around by forces and other objects.
- Static: Fixed obstacles. They never move during the simulation. Pro tip: You can manually keyframe a Static body in AE, and dynamic objects will react to it as a moving wall!
Collider Shapes
- Box / Circle: Fast, mathematical boundaries wrapped around your layer's dimensions. Adjust the Rounding (Chamfer) slider to smooth out box corners.
- Mask: Draws the physics boundary exactly along your custom AE mask path! Use this for complex, custom layer shapes.
Comp Boundaries & Null Parenting
You can easily toggle the physical walls of your composition edge. Toggle Use Comp Boundary as Walls and choose between a "Full Box" (so nothing flies off-screen) or "Floor Only". Use the margin slider to shrink the walls inward.
The Parent to Nulls toggle creates an empty Null Object for every body, applying the physics to the null, and parenting your visual layer to it. This is incredibly useful for adding secondary animation atop the physics.
Step 2: Groups & Overrides
Groups allow you to apply specific rules to a subset of your bodies. For example, you might want red squares to launch upwards while blue circles fall downwards.
AE Label Integration
Grouping is seamlessly integrated with After Effects. Click Auto by Label, and FiziFlo will instantly create groups based on the AE label colors assigned to your layers in the timeline!
Available Overrides per Group
Gives the group an immediate push on frame 0. Great for cannons or fountains.
Scatters the launch direction and rotation. Perfect for particle explosions and debris.
A powerful feature. Turning this on means bodies within this specific group will ignore hitting each other, but will still hit everything else. Ideal for text characters flowing together without jumbling into a mess.
Step 3: Global Physics Defaults
Set the rules of the world. These sliders control the engine broadly (unless overridden by a group). You can start fast by selecting a preset from the top dropdown (like "Bounce" or "Zero-G") and then tweaking these values.
Controls the constant downward (or sideways) pull on all dynamic objects. Vertical gravity pulls down dynamically.
Energy retention. 0 means dead stop on impact, 100 means a perfect, endless bounce.
How "sticky" surfaces are when sliding against each other. High static friction makes objects harder to push from a standstill.
Acts like drag, slowing down fast-moving or spinning objects constantly during the simulation. Great for feathers or leaves.
Heavier objects are harder to push and will aggressively plow through lighter objects.
Optimization technique. When checked, bodies that come to rest are "put to sleep" by the engine to save processing power and stop micro-jitters.
Constraints & Environmental Forces
Take your scene further by chaining objects together or applying powerful cinematic forces. FiziFlo uses native AE constructs (Parenting and Null objects) to control these advanced features seamlessly.
Body Joints (Constraints)
To link two bodies together with a physical joint or spring constraint, simply parent the layers together in the After Effects timeline before clicking "Build from Selection". FiziFlo automatically reads the AE parenting chain and builds physical constraints.
- Joint Rigidity: 100% acts as a solid metal rod. Lower percentages turn the joint into an elastic spring.
- Spring Decay: Controls how quickly a bouncing spring stiffens and settles down back to its resting length.
Environmental Forces (Controlled via Nulls)
Stack dynamics like explosions or vortexes. When you add an origin-based force, click "Create Null" in the panel. FiziFlo generates an appropriately named Null (e.g., MF Explosion). You position this Null in your AE Comp to control exactly where the force originates!
Wind
Applies a continuous, uniform directional push across the entire composition. Simply define the angle and strength.
Vortex (Tornado)
Spins all dynamic objects in an orbit around the MF Vortex Null center point. Great for swirling reveals.
Boom (Explosion)
An instantaneous outward shockwave originating precisely from the MF Explosion Null object on the very first frame.
Push/Pull (Magnet)
Continuously attracts (positive) or repels (negative) bodies toward the MF Attraction Null. Perfect for clustering elements.
Step 6: Output & Bake
The final step! Running the physics solver and injecting standard transformations onto your layers.
- Duration: How many seconds of simulation to calculate and bake into keyframes. Longer durations take longer to process.
- Simulation Speed: Speed up or slow down time. 50% yields beautiful slow-motion collisions and bounces.
- Keyframe Interval: Crucial for heavy scenes. Setting this to 1 writes a key on every frame. Setting this to 3 writes a key every third frame, vastly reducing AE bloat while maintaining solid playback.
- Bake / Cancel / Clear: Click "Bake Simulation" to begin. The engine is robust; if a bake is taking too long on a dense comp, simply hit the Cancel icon to cleanly stop. Use "Clear Keyframes" to wipe the keys and try again!
Troubleshooting & Solver Quality
My bodies pack too tightly/intersect during simulations!
This is caused when the density of the layer stack exceeds the resolution of the solver step. To fix this: Change the Simulation Quality to Stable or Precise. This allows the engine to iterate collision checks far more times per frame, resolving intersections cleanly.
Why does After Effects feel slow when baking?
Simulating hundreds of layers using complex Mask colliders over a long Duration (for instance, 30s) requires intense calculation looping between the Panel and AE's core. Ensure you start with low layer counts, or increase your Keyframe Interval to ease the data-writing load.
Clear Keyframes isn't working on some nested pre-comps.
FiziFlo targets exact IDs based on the original build pass. If you have heavily mutated a layer tree (duplicating, cutting, changing source bounds) in the AE timeline manually *after* baking, it may lose its reference track. You will need to manually delete the position/rotation keys for those fragmented layers.
Need Further Help?
Hit a snag compiling complex convex hulls, or noticing performance drops? Reach out!