Over-Life Curves
Changing size, color and opacity across a particle life
Also known as: Color over life · Size over life · Alpha over life · Over lifetime curve · Particle curves · Scale by life
Definition
Over-life curves control how a particle's properties change from the moment it spawns to the moment it dies. Typical curves drive size, color, opacity, speed and rotation, such as a spark that starts bright and small, grows quickly and then fades out, or smoke that expands and becomes transparent. These curves, shown as graphs or gradients in the editor, are the main tool for giving an effect its feel, and are called Color over Lifetime in Unity and Color From Curve in Niagara.
In production
Design the curve shape on purpose: a quick rise and a slow fall feels natural for fire, while an even fade looks mechanical. Use a gradient of color for fire, from white and yellow at the start to orange, red and dark at the end. Fade opacity in at the start and out at the end to avoid pops. Reuse the same curves in a library, and adjust their length to the lifetime.
Learn Over-Life Curves in
Tools that use Over-Life Curves
See also
Particle System
Spawns and animates many small elements
Niagara
UE5 particle and VFX system
VFX Timing (Anticipation, Impact, Dissipation)
The rhythm that makes an effect feel right
Additive vs Alpha Blending
Two ways particles combine with the scene
Ribbons and Trails
Strips that follow a moving point
Flipbook (Sprite Sheet)
Animated texture made of a grid of frames