Techniques

import { echo, smear, squeeze, svg } from "@web-kits/motion-blur";

motionBlur(el, { technique: squeeze({ factor: 16 }) });

Technique	Options
`echo()`	`spacing = 1.5`, `copies = 16`	Copies of the layer along the path at `1/n` opacity, added with `plus-lighter`. The only one shaped like a camera's blur, and the only one that follows a curve.
`squeeze()`	`factor = 16`	A CSS blur stretched along the motion by scaling the layer before the filter. No copies, so it's the cheapest blur.
`svg()`		`feGaussianBlur` along one axis, rotated to the direction of motion.
`smear()`	`limit = 1.05`	Stretches the layer along the motion. Nothing is blurred, so keep the limit low on anything with text.

Pick a technique, then slow it down or press Still to stop the square at its fastest point, where the shape of each blur is easiest to see. Blur is a plain CSS blur() for comparison.

Echo gets one copy for every spacing px of streak, up to copies. Squeeze and SVG rotate the layer and its child in opposite directions, so the layer must have exactly one element child.