Distort
The three distort effects — Twirl, Bulge, and Ripple — their falloffs, their fixed centre, and what each one really does.
Reference
- Panel
- Effect Controls
- Section
- Add effect ▸ Distort
The Distort family holds 3 effects. Each one resamples the layer rather than recolouring it, so the layer's own colours are preserved and only their positions change.
Twirl and Bulge both work about the centre of the frame, which is fixed and cannot be moved. Both are bounded by a Radius measured as a fraction of half the frame's shorter side, and both leave everything outside that radius untouched.
The sections below follow the order of the Distort submenu.
The distort effects
Twirl
Rotates pixels about the frame centre by an angle that is strongest at the centre and falls to zero at Radius. The falloff is quadratic, so the twist stays concentrated near the middle and eases out well before the boundary — the edge of the effect is not a visible seam.
The twist at the very centre. The sign sets the direction of rotation.
The extent of the twist, as a fraction of half the frame's shorter side. At 1.0 the twist reaches half that side's length.
Bulge
Remaps each pixel's distance from the frame centre, magnifying the middle outward (a bulge) or drawing it inward (a pinch). Pixels outside Radius pass through untouched.
Positive values bulge, magnifying the centre. Negative values pinch.
The extent of the distortion, as a fraction of half the frame's shorter side.
Amount -1 is a degenerate case
At exactly -1 the remap collapses: every pixel inside Radius samples the colour at the rim, and the whole disc floods with that single colour. Values near -1 pinch increasingly hard as they approach it. Stop short of the end of the slider for a usable pinch.
Ripple
Displaces each pixel horizontally by an amount driven by a sine wave running down the frame. The result is a wavy horizontal shear — a flag-wave — applied uniformly across the whole layer.
Ripple is not a concentric ripple
Despite the name, Ripple produces no rings and has no centre. It shears the image sideways in waves; it does not radiate from a point. For a radiating, animated ripple, use the Ripple Warp style of the Transition effect.
The horizontal displacement, as a fraction of the frame's width. The maximum, 0.08, displaces by about eight percent of the frame's width.
The number of waves from the top of the frame to the bottom.
Ripple has no phase control, so it is static on its own — the waves sit where they are and do not travel. To animate it, keyframe Amplitude or Frequency; see Keyframes.