[nuccy]

Indeed, all those animations are pre-rendered videos embedded in the page, which are then randomly selected. I find shadertoy [1] really impressive, given that those animations are calculated/rendered in real-time.

A while ago after being impressed by shadertoy I've built a website (now offline) with a shader as a background using Tree.js [2]. The website was showing caustics - constantly-changing ridges of light produced on the bottom of the pool/lake/sea when light passes through the waves (similar to [3]). People visiting it were always assuming those are pre-rendered videos and were genuinely surprised that their N-years old phone is capable of running that shader in real-time flawlessly.

1. https://www.shadertoy.com/browse (click Hot or Popular button to sort)

2. https://threejs.org/docs/#api/en/materials/ShaderMaterial

3. https://www.shadertoy.com/view/wlc3zr

[OsrsNeedsf2P]

Shadertoy is a blast, and if you use KDE, you can make your wallpaper use it[0]

0. https://github.com/y4my4my4m/kde-shader-wallpaper