Tunnel

A corridor flying past lit rings

A corrugated corridor seen from inside, curving away into the dark, with bright rings passing overhead at regular intervals. The camera flies forward continuously. The most expensive shader here, and the only one with real depth.

Rendering cost: heavy. A raymarch or escape-time loop per pixel: cap the pixel ratio, or keep it to a card rather than a fullscreen background. How to tune it

Take Tunnel with you.

Tunnel is free. Sign in and it is yours — the background itself, with your settings already saved in, ready to drop into your site. The account is only somewhere to put the files. No card now, and no card later.

The other 61 come with a licence, $9.99 once.

$0forever

Your preset is in the URL. It survives the trip.