Federico Valla's Smooothy is, technically, a carousel library. The demo page gives this away by making you scroll through Toast, Fish but no Head, Hotdog, Ramen Bowl, and Just a Fungus, all priced at 33.23¥.
Smooothy is built to be the carousel underneath your scene, not over it. The Core class is a few hundred lines of TypeScript that exposes everything a shader actually cares about (current, target, progress, speed, parallaxValues, deltaTime) through an onUpdate callback you wire into your own RAF loop.
Worth the click for the configurable demo alone. Drag it around, hit the source code to see how the parallax values get piped into the actual GLSL.
