Pool shader preview: Clear water from above, with refraction, caustics and sun glints.
ittybitty

Pool

Clear water from above, with refraction, caustics and sun glints.

Code

The usage always matches the preview, layers and performance settings included. No build step or package.

Copy embed gives one block to paste into any page or site builder, no setup. For your own code: add water.js, ittybitty-shader.js, runtime.js, container.js, pointer.js, shape.js, texture.js next to this page. Highlighted values follow the controls.

<!-- Quickest: one element. Size it with CSS; it fills its box. -->
<script type="module" src="./ittybitty-shader.js"></script>
<ittybitty-shader effect="water" style="width: 100%; height: 480px;"></ittybitty-shader>

<!-- Or with JavaScript, for full control: -->
<canvas id="water" aria-hidden="true" style="width: 100%; height: 480px; display: block"></canvas>

<script type="module">
  import { water } from './water.js';

  const canvas = document.getElementById('water');
  const effect = water(canvas, {
    showFloor: true,
    showCaustics: true,
    showSheen: true,
    showGlints: true,
    speed: 0.5,
    scale: 1,
    refraction: 0.6,
    caustics: 0.8,
    depth: 0.45,
    glints: 0.5,
    interactive: true,
    responsiveness: 0.5,
    floor: 'tiles',
    water: '#2fb6c7',
    container: 'off',
    outline: 'itty',
    edgeLight: 0.6,
    rim: 0.6,
    gloss: 0.5,
    innerShadow: 0.5,
    // Performance
    dpr: 1.5,
    adaptive: true,
  });

  // Later: effect.set(…), effect.pause(), effect.resume(), effect.destroy()
</script>

Details

A moving surface bends your view of the floor beneath it and focuses sunlight into shimmering caustics with a faint rainbow fringe. Light is absorbed with depth, and wave crests catch the sun. One pass, no textures, no simulation.

Payload
9.8 KB brotli for water.js and ittybitty-shader.js and runtime.js and container.js and pointer.js and shape.js and texture.js, measured at build time. See the method.
Resolution
Device pixel ratio capped at 1.5. Adaptive resolution steps down on slow devices.
Frame rate
Display rate.
When unseen
Stops rendering when the canvas leaves the viewport or the tab is hidden, and resumes where it left off.
Reduced motion
Shows a single still frame. Controls still update it.
Layers
Up to five effects fuse into one shader and one draw call. Filters such as dithering and halftone process the layers beneath them.
Browsers
Any browser with WebGL2: Chrome and Edge 56+, Firefox 51+, Safari 15+.
Licence
MIT. Copy it, change it, ship it.