parabola
Generates a symmetrical parabolic curve where an input in the [0, 1] range results in an output that smoothly rises from 0 to 1 (at 0.5) and back to 0. Often used for creating soft masks and beam profiles.
Core Advantages
Generates a smooth curve that is 1 at the center and 0 at the ends without textures, with its sharpness precisely controlled by a single 'k' parameter, ideal for effects like vignettes and beams that require a smooth falloff.
Common Uses
Creating soft vignette effects
Simulating energy beams or lightsabers
Creating dynamic pulse or heartbeat animations
How to adjust
Control the curve's shape primarily by adjusting the 'k' parameter. `k > 1` makes the curve sharper and narrower; `0 < k < 1` makes it flatter and wider. Animating 'k' with a time node creates a pulsing effect.
Code Examples
1// Create a mask with a sharp center and falloff
2// k > 1.0 makes the curve sharper
3const sharpMask = parabola( uv().x, 8.0 );