Ribbon Scan

Rolls soft horizontal ribbons down the picture that push it sideways, like a wobbling video signal. At low values a face stays readable; at the top of the range the picture tears apart.

Group: Analog & Glitch · How to add an effect

The dancer on a dark stage, original left and with Ribbon Scan at its default settings right: the outlines of her dress, arms and legs ripple sideways in many thin horizontal waves, while her face stays readable — Left: original. Right: default settings (Displacement 0.3); the ribbons roll down over time.

Use it for: a wavering signal or heat haze · a dreamlike wobble on a performer · a transition (animate Displacement up and back).

Ribbons – how many ribbons fit in the picture height (at least 3).
Displacement – how far the ribbons push the picture. It grows gently: at the default 0.3 a face stays readable, at 1 the picture tears apart.
Edges – whether reads past the frame edge mirror back (Mirror) or wrap around to the other side (Wrap).
Speed – how many ribbons roll past per second; 0 holds them still.

Tip: for a few slow, large waves, set Ribbons to 3 and Speed to 0.2.

Controls

Control	Range	Default
Pattern
Ribbons	3 to 80	14
Style
Displacement	0 to 1	0.3
Edges	Mirror, Wrap	Mirror
Motion
Speed	0 to 5	1

Node setup

The sideways shift of Ribbon Scan as a recipe: Displacement feeds both inputs of a Multiply (Displacement squared), which is multiplied by a Value of 0.06; that reach is multiplied by Ribbon Wave and then by Ribbon Envelope into the shift — The shift: Displacement² × 0.06 × the wave × the envelope of the ribbon.

Ribbon Scan is one flat node graph. Each ribbon has a phase that runs from top to bottom and scrolls with time; Ribbon Wave is the sine of that phase, and Ribbon Envelope fades the ribbon in over its first 18 % and out over its last 38 %. The first Multiply squares Displacement, so the low half of the control stays subtle, and the Value of 0.06 sets the largest shift: 6 % of the frame width. How to open it: The node setup.

Remix: for a shift that grows evenly with the slider, unplug input B of the first Multiply and plug a Value of 1 into it. Then 0.3 pushes 1.8 % of the width instead of 0.54 %.

Technical details

Units. The shift is sin(2π × phase) × Displacement² × 6 % of the frame width: at most 0.54 % at the default 0.3. Ribbons below 3 render as 3, and the inspector says so.
Transparency. Both reads come from a premultiplied cache and blend premultiplied, so cut-out edges keep their colour. Reads past the frame edge mirror or wrap instead of smearing the edge pixel.
Time. The ribbons scroll by Speed ribbons per second of timeline time; the preview, scrubbing and the export match. Displacement 0 leaves every pixel unchanged.
Saved projects. A Ribbon Scan saved before the 2026-10 rebuild keeps its earlier look (a shift of up to 8 %, clamped edges) and has no Edges control; add the effect again for the current version.

The recipe: Effect system: Ribbon Scan. Nodes: Node Catalog.