The bright, shifting web of light that sunlight throws on the floor of a pool. Two layers of light lines drift and fold over aqua and turquoise water, the brightest lines carry a faint rainbow fringe, and shallow and deep patches drift slowly underneath.

A fresh background for summer, travel, swimwear, spa and beach pages, and for pool party invitations and video titles. Set the deep, shallow and light colours, the size of the light web, its brightness and sharpness, the rainbow fringe, and pool tiles that wobble under the water. The demo has three presets: Lagoon, Pool tiles and Mermaid.

What you get: a GLSL ES 3.00 fragment shader for plain WebGL2, an ES module that returns a three.js ShaderMaterial, a Shadertoy version, and a demo page that runs offline with a small settings panel. For video editors there is a 10-second 1920 x 1080 H.264 loop that plays end to start without a seam.

It runs in one pass with no textures needed, at about 1.9 ms of GPU time per frame at 1920 x 1080 on a recent laptop. The README covers set-up in WebGL2, three.js and Shadertoy, every uniform with its default and range, and performance notes.